Release extension version 0.3.35 (#297)

Co-authored-by: GitHub Actions <github-actions@github.com>

.github/CODEOWNERS

@@ -1 +1 @@
-* @actions/actions-workflow-development-reviewers
+* @actions/actions-vscode-reviewers

.github/dependabot.yml

@@ -0,0 +1,16 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
+
+version: 2
+updates:
+  - package-ecosystem: "npm" # See documentation for possible values
+    directories: 
+      - "/"
+      - "/languageservice"
+      - "/languageserver"
+      - "expressions"
+      - "browser-playground"
+    schedule:
+      interval: "weekly"

.github/workflows/buildtest.yml

@@ -1,4 +1,6 @@
 name: Build & Test
+permissions:
+  contents: read
 
 on:
   push:
@@ -10,18 +12,55 @@ jobs:
   build:
     runs-on: ubuntu-latest
 
+    strategy:
+      matrix:
+        node-version: [18.x, 20.x, 22.x]
+
     steps:
-    - uses: actions/checkout@v3
-    - name: Use Node.js 16.15
-      uses: actions/setup-node@v3
+    - uses: actions/checkout@v4
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v4
       with:
-        node-version: 16.15
+        node-version: ${{ matrix.node-version }}
         cache: 'npm'
         registry-url: 'https://npm.pkg.github.com'
-    - run: npm ci
+    - run: npm ci --engine-strict
       env:
         NODE_AUTH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     - run: npm run format-check -ws
     - run: npm run build -ws
     - run: npm run lint -ws
     - run: npm test -ws
+
+  check-generated:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Use Node.js 22.x
+      uses: actions/setup-node@v4
+      with:
+        node-version: 22.x
+        cache: 'npm'
+        registry-url: 'https://npm.pkg.github.com'
+    - run: npm ci
+      env:
+        NODE_AUTH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+    - name: Regenerate JSON files
+      run: |
+        cd languageservice && npm run update-webhooks && cd ..
+    - name: Check for uncommitted changes
+      run: |
+        if ! git diff --exit-code; then
+          echo ""
+          echo "=========================================="
+          echo "ERROR: Generated files are out of date!"
+          echo "=========================================="
+          echo ""
+          echo "Please run the following commands locally and commit the changes:"
+          echo ""
+          echo "  cd languageservice && npm run update-webhooks && cd .."
+          echo "  git add -A && git commit -m 'Regenerate JSON files'"
+          echo ""
+          exit 1
+        fi

.github/workflows/publish.yml

@@ -1,13 +1,18 @@
 name: Create release PR
 
-run-name: Create release PR for v${{ github.event.inputs.version }}
+run-name: Create release PR for new ${{ github.event.inputs.version }} version
 
 on:
   workflow_dispatch:
     inputs:
       version:
         required: true
-        description: "Version to bump `package.json` to (format: x.y.z)"
+        type: choice
+        description: "What type of release is this"
+        options:
+          - "major"
+          - "minor"
+          - "patch"
 
 jobs:
   create-release-pr:
@@ -20,9 +25,9 @@ jobs:
       pull-requests: write
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
-      - uses: actions/setup-node@v3
+      - uses: actions/setup-node@v4
         with:
           node-version: "16"
 
@@ -31,21 +36,27 @@ jobs:
           git config --global user.email "github-actions@github.com"
           git config --global user.name "GitHub Actions"
 
-          git checkout -b release/${{ inputs.version }}
+          NEW_VERSION=$(./script/workflows/increment-version.sh ${{ inputs.version }})
 
-          npx lerna version ${{ inputs.version }} --yes --no-push --no-git-tag-version --force-publish
+          git checkout -b release/$NEW_VERSION
+
+          npx lerna version $NEW_VERSION --yes --no-push --no-git-tag-version --force-publish
 
           git add **/package.json package-lock.json lerna.json
-          git commit -m "Release extension version ${{ inputs.version }}"
+          git commit -m "Release extension version $NEW_VERSION"
 
-          git push --set-upstream origin release/${{ inputs.version }}
+          git push --set-upstream origin release/$NEW_VERSION
+
+          echo "new_version=$NEW_VERSION" >> $GITHUB_ENV
 
       - name: Create PR
         run: |
+          LAST_PR=$(gh pr list --repo ${{ github.repository }} --limit 1 --state merged --search "Release version" --json number | jq -r '.[0].number')
+          ./script/workflows/generate-release-notes.sh $LAST_PR ${{ env.new_version }}
           gh pr create \
-            --title "Release version ${{ inputs.version }}" \
-            --body "Release version ${{ inputs.version }}" \
+            --title "Release version ${{ env.new_version }}" \
+            --body-file releasenotes.md \
             --base main \
-            --head release/${{ inputs.version }}
+            --head release/${{ env.new_version }}
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/release.yml

@@ -24,10 +24,10 @@ jobs:
       contents: read
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Check if version has changed
         id: check-version
-        uses: actions/github-script@v6
+        uses: actions/github-script@v7
         with:
           script: |
             const version = '${{ inputs.version }}' || require('./lerna.json').version;
@@ -65,11 +65,11 @@ jobs:
       PKG_VERSION: "" # will be set in the workflow
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
-      - uses: actions/setup-node@v3
+      - uses: actions/setup-node@v4
         with:
-          node-version: 16.x
+          node-version: 22.x
           cache: "npm"
           scope: '@actions'
 
@@ -80,7 +80,7 @@ jobs:
       - run: npm ci
 
       - name: Create release
-        uses: actions/github-script@v6
+        uses: actions/github-script@v7
         with:
           script: |
             const fs = require("fs");

.gitignore

@@ -1,5 +1,16 @@
 */node_modules
 */dist
-
+lerna-debug.log
 node_modules
-.DS_Store
+.DS_Store
+
+# Nx cache (generated by Lerna/Nx)
+.nx/
+
+# Minified JSON (generated at build time)
+*.min.json
+
+# Intermediate JSON for size comparison (generated by update-webhooks --all)
+*.all.json
+*.drop.json
+*.strip.json

README.md

@@ -8,6 +8,24 @@ This repository contains multiple npm packages for working with GitHub Actions w
 - [languageserver](./languageserver) - Language Server for GitHub Actions, hosting the language service for LSP-compatible editors
 - [browser-playground](./browser-playground) - Browser-based playground for the language service
 
-## Contributing
+## Documentation
 
-See [CONTRIBUTING.md](./CONTRIBUTING.md)
+- [JSON Data Files](./docs/json-data-files.md) - How the JSON data files are generated and maintained
+
+### Note
+
+Thank you for your interest in this GitHub repo, however, right now we are not taking contributions. 
+
+We continue to focus our resources on strategic areas that help our customers be successful while making developers' lives easier. While GitHub Actions remains a key part of this vision, we are allocating resources towards other areas of Actions and are not taking contributions to this repository at this time. The GitHub public roadmap is the best place to follow along for any updates on features we’re working on and what stage they’re in.
+
+We are taking the following steps to better direct requests related to GitHub Actions, including:
+
+1. We will be directing questions and support requests to our [Community Discussions area](https://github.com/orgs/community/discussions/categories/actions)
+
+2. High Priority bugs can be reported through Community Discussions or you can report these to our support team https://support.github.com/contact/bug-report.
+
+3. Security Issues should be handled as per our [security.md](security.md)
+
+We will still provide security updates for this project and fix major breaking changes during this time.
+
+You are welcome to still raise bugs in this repo.

browser-playground/package.json

@@ -34,6 +34,6 @@
     "typescript": "^4.9.4",
     "webpack": "^5.75.0",
     "webpack-cli": "^5.0.1",
-    "webpack-dev-server": "^4.11.1"
+    "webpack-dev-server": ">=5.2.1"
   }
 }

docs/esm-migration-plan.md

@@ -0,0 +1,319 @@
+# ESM Migration Plan: Add File Extensions to Imports
+
+## Overview
+
+This document outlines the plan to migrate from TypeScript's deprecated `"moduleResolution": "node"` (node10) to `"moduleResolution": "node16"` or `"nodenext"`. This change is necessary because the published ESM packages have extensionless imports that don't work correctly in modern ESM environments.
+
+## TL;DR - Remaining Work
+
+- [x] expressions - Migrated ✅
+- [x] workflow-parser - Migrated ✅
+- [x] languageservice - Migrated ✅
+- [x] languageserver - Add `.js` extensions to imports ✅
+- [ ] languageserver - Update `tsconfig.build.json` to `moduleResolution: "node16"` (blocked by vscode-languageserver)
+- [ ] languageserver - Upgrade `vscode-languageserver` to stable v10+ when released
+
+**Blocker:** `vscode-languageserver@8.0.2` lacks ESM exports. Stable v10 with `exports` field needed.
+
+### ⚠️ Important: `skipLibCheck: true` Required
+
+All migrated packages use `skipLibCheck: true` in their `tsconfig.build.json`. This works around a TS2386 "Overload signatures must all be optional or required" error in `@types/node/module.d.ts`.
+
+**Why can't we just fix the error?** The error is in `@types/node`, a third-party package maintained by DefinitelyTyped. We can't modify `node_modules`, and upstream fixes take time.
+
+**Is `skipLibCheck` safe?** Yes. It only skips type checking of `.d.ts` files (declaration files from dependencies). Our own `.ts` source files are still fully type-checked. This is a common and recommended workaround for issues in third-party type definitions.
+
+---
+
+## Issues Fixed
+
+This migration will resolve the following issues:
+
+- **#154** - Upgrade `moduleResolution` from `node` to `node16` or `nodenext` in tsconfig
+- **#110** - Published ESM code has imports without file extensions
+- **#64** - expressions: ERR_MODULE_NOT_FOUND attempting to run example demo script  
+- **#146** - Can not import `@actions/workflow-parser`
+
+## Problem Statement
+
+### Current State
+
+All packages use `"moduleResolution": "node"`:
+
+| Package | moduleResolution | TypeScript |
+|---------|------------------|------------|
+| expressions | `"node"` | ^4.7.4 |
+| workflow-parser | `"node"` | ^4.8.4 |
+| languageservice | `"node"` | ^4.8.4 |
+| languageserver | `"node"` | ^4.8.4 |
+| browser-playground | `"Node16"` ✅ | ^4.9.4 |
+
+This causes TypeScript to emit code like:
+```javascript
+// Published to npm - INVALID ESM
+export { Expr } from "./ast";  // Missing .js extension!
+```
+
+### Why This Fails
+
+ESM in Node.js 12+ **requires** explicit file extensions. When users try to import these packages:
+
+```javascript
+// User's code
+import { Expr } from "@actions/expressions";
+```
+
+Node.js fails with:
+```
+Error [ERR_MODULE_NOT_FOUND]: Cannot find module '.../node_modules/@actions/expressions/dist/ast'
+```
+
+## Migration Strategy
+
+### Option A: TypeScript 5.7+ with `rewriteRelativeImportExtensions` (Recommended)
+
+TypeScript 5.7 introduced a new compiler option that automatically rewrites `.ts` extensions to `.js` in output:
+
+```jsonc
+{
+  "compilerOptions": {
+    "moduleResolution": "node16",  // or "nodenext"
+    "rewriteRelativeImportExtensions": true
+  }
+}
+```
+
+**Source code:**
+```typescript
+import { Expr } from "./ast.ts";
+```
+
+**Compiled output:**
+```javascript
+export { Expr } from "./ast.js";
+```
+
+**Pros:**
+- Source uses `.ts` extensions (matches actual files)
+- Works with Deno (which requires `.ts` extensions)
+- TypeScript automatically transforms to `.js`
+- Modern, forward-looking approach
+
+**Cons:**
+- Requires TypeScript 5.7+
+- Relatively new feature
+- **BUG:** See "Known Issues" section below
+
+### Option B: Manual `.js` Extensions
+
+Use `.js` extensions in source TypeScript files:
+
+```typescript
+import { Expr } from "./ast.js";  // Points to .ts file, but use .js extension
+```
+
+**Pros:**
+- Works with TypeScript 4.7+ (with node16 moduleResolution)
+- Well-established pattern
+- No post-processing needed
+- Works with ts-jest without extra configuration
+
+**Cons:**
+- Confusing - `.js` files don't exist at write time
+- Doesn't work with Deno out of the box
+
+### Recommendation
+
+**Use Option B** (manual `.js` extensions). Option A with `rewriteRelativeImportExtensions` has compatibility issues with ts-jest and requires additional workarounds.
+
+---
+
+## Known Issues and Workarounds (December 2025)
+
+### 1. TypeScript Version Conflicts in Monorepo
+
+**Problem:** The root `node_modules/typescript` was version 4.9.5 (pulled in by `ts-node` and `tsutils` dependencies), while workspace packages specified `^5.8.3`.
+
+**Symptoms:** 
+- `npx tsc --version` showed 4.9.5
+- `require('typescript').version` in ts-jest showed 5.8.3
+- Confusing build failures
+
+**Solution:** Add npm overrides in root `package.json`:
+```json
+{
+  "overrides": {
+    "typescript": "5.8.3"
+  }
+}
+```
+
+### 2. ts-jest Compatibility with TypeScript 5.9+
+
+**Problem:** ts-jest 29.4.6 uses `typescript.JSDocParsingMode.ParseAll` which doesn't exist in TypeScript's ES module exports.
+
+**Error:**
+```
+TypeError: Cannot read properties of undefined (reading 'ParseAll')
+at Object.<anonymous> (node_modules/ts-jest/dist/compiler/ts-compiler.js:43:123)
+```
+
+**Root Cause:** ts-jest accesses `typescript_1.default.JSDocParsingMode.ParseAll` but TypeScript has no default export in ESM.
+
+**Solution:** 
+- Use ts-jest 29.0.3 (older version that doesn't use this API)
+- OR wait for ts-jest fix
+- **Stay on TypeScript 5.8.3, not 5.9+**
+
+### 3. TypeScript `rewriteRelativeImportExtensions` Bug with .d.ts Files
+
+**Problem:** TypeScript's `rewriteRelativeImportExtensions: true` correctly rewrites `.ts` → `.js` in `.js` output files, but **incorrectly keeps `.ts` extensions in `.d.ts` declaration files**.
+
+**Example:**
+- Source: `export { Expr } from "./ast.ts";`
+- Output `index.js`: `export { Expr } from "./ast.js";` ✅ Correct
+- Output `index.d.ts`: `export { Expr } from "./ast.ts";` ❌ Wrong (should be `.js`)
+
+**Upstream Issue:** https://github.com/microsoft/TypeScript/issues/61037 (marked "Help Wanted", in Backlog, NOT FIXED as of Dec 2025)
+
+**Workaround:** Post-process `.d.ts` files with a script. See `script/fix-dts-extensions.cjs`.
+
+**Note:** Since we use Option B (manual `.js` extensions), this bug does not affect our migration.
+
+### 4. yaml Package Internal Types Not Exported
+
+**Problem:** The `yaml` package does not export internal types like `LinePos` and `NodeBase` that are used in `workflow-parser/src/workflows/yaml-object-reader.ts`.
+
+**Error:**
+```
+error TS2305: Module '"yaml"' has no exported member 'LinePos'.
+error TS2305: Module '"yaml"' has no exported member 'NodeBase'.
+```
+
+**Solution:** Define local type aliases in the file that uses them:
+```typescript
+// Local type definitions to replace yaml internal imports
+type LinePos = { line: number; col: number };
+type NodeBase = { range?: [number, number, number] };
+```
+
+### 5. languageserver Blocked by vscode-languageserver Dependency
+
+**Problem:** The `vscode-languageserver` package (v8.0.2) does not have proper ESM exports. When using `moduleResolution: "node16"`, TypeScript requires packages to have an `exports` field in `package.json` for subpath imports to work.
+
+**Error:**
+```
+src/index.ts(6,8): error TS2307: Cannot find module 'vscode-languageserver/browser' or its corresponding type declarations.
+src/connection.ts(1,43): error TS2307: Cannot find module 'vscode-languageserver/node' or its corresponding type declarations.
+```
+
+**Root Cause:** The `vscode-languageserver` package.json only has `main` and `browser` fields, but no `exports` field:
+```json
+{
+  "main": "./lib/node/main.js",
+  "browser": {
+    "./lib/node/main.js": "./lib/browser/main.js"
+  }
+  // No "exports" field!
+}
+```
+
+With `moduleResolution: "node16"`, TypeScript follows Node.js ESM resolution rules which require explicit `exports` for subpath imports like `vscode-languageserver/browser` and `vscode-languageserver/node`.
+
+**Status:** Partial - `.js` extensions added, waiting for stable `vscode-languageserver` release with ESM exports to complete migration.
+
+**Completed:** All relative imports in languageserver source files have been updated to use `.js` extensions. This is compatible with the current `moduleResolution: "node"` and will enable a seamless migration once a stable vscode-languageserver version with ESM exports is available.
+
+**Options to resolve:**
+- Wait for stable vscode-languageserver v10+ with ESM exports
+- Use pre-release `vscode-languageserver@10.0.0-next.16` (has proper exports but is unstable)
+- Fork or patch the dependency
+
+---
+
+## Migration Status
+
+| Package | Tests | ESM Status |
+|---------|-------|------------|
+| expressions | 1068 | ✅ Migrated |
+| workflow-parser | 292 | ✅ Migrated |
+| languageservice | 452 | ✅ Migrated |
+| languageserver | 31 | 🔶 Partial (`.js` extensions added, awaiting stable vscode-languageserver) |
+
+---
+
+## Required Configuration Changes
+
+### tsconfig.build.json (each migrated package)
+
+**Note:** We use **Option B** (manual `.js` extensions in source files) rather than `rewriteRelativeImportExtensions` because Option A caused ts-jest compatibility issues (tests would hang indefinitely).
+
+```json
+{
+  "compilerOptions": {
+    "module": "node16",
+    "moduleResolution": "node16",
+    "skipLibCheck": true,
+    "lib": ["ES2022"],
+    "target": "ES2022"
+  }
+}
+```
+
+The `skipLibCheck: true` is needed to work around @types/node compatibility issues with TypeScript 5.x (TS2386 overload signature errors).
+```
+
+### jest.config.js (each migrated package)
+
+```javascript
+/** @type {import('ts-jest').JestConfigWithTsJest} */
+export default {
+  preset: "ts-jest/presets/default-esm",
+  moduleNameMapper: {
+    "^(\\.{1,2}/.*)\\.js$": "$1",
+    "^(\\.{1,2}/.*)\\.ts$": "$1",
+  },
+  transform: {
+    "^.+\\.tsx?$": [
+      "ts-jest",
+      {
+        useESM: true,
+        isolatedModules: true,
+      },
+    ],
+  },
+  moduleFileExtensions: ["ts", "js"],
+};
+```
+
+### Root package.json
+
+```json
+{
+  "overrides": {
+    "typescript": "5.8.3"
+  }
+}
+```
+
+### Each workspace package.json
+
+```json
+{
+  "devDependencies": {
+    "typescript": "^5.8.3",
+    "ts-jest": "^29.0.3"
+  }
+}
+```
+
+---
+
+## References
+
+- [TypeScript moduleResolution reference](https://www.typescriptlang.org/docs/handbook/modules/reference.html)
+- [TypeScript 5.7 rewriteRelativeImportExtensions](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-5-7.html#path-rewriting-for-relative-paths)
+- [TypeScript .d.ts extension bug #61037](https://github.com/microsoft/TypeScript/issues/61037)
+- [Node.js ESM mandatory extensions](https://nodejs.org/api/esm.html#mandatory-file-extensions)
+- [ts-jest ESM support](https://kulshekhar.github.io/ts-jest/docs/guides/esm-support)
+- [Community fork that works](https://github.com/boxbuild-io/actions-languageservices/commit/077fb2b58dfd2cca3d6e3df1fdf9e26e75db24ae)

docs/json-data-files.md

@@ -0,0 +1,197 @@
+# JSON Data Files
+
+This document describes the JSON data files used by the language service packages and how they are maintained.
+
+## Overview
+
+The language service uses several JSON files containing schema definitions, webhook payloads, and other metadata. To reduce bundle size, these files are:
+
+1. **Optimized at generation time** — unused events are dropped, unused fields are stripped
+2. **Minified at build time** — whitespace is removed to produce `.min.json` files
+
+The source `.json` files are human-readable and checked into the repository. The `.min.json` files are generated during build and gitignored.
+
+## Files
+
+### languageservice
+
+| File | Description |
+|------|-------------|
+| `src/context-providers/events/webhooks.json` | Webhook event payload schemas for autocompletion |
+| `src/context-providers/events/objects.json` | Deduplicated shared object definitions referenced by webhooks |
+| `src/context-providers/events/schedule.json` | Schedule event context data |
+| `src/context-providers/events/workflow_call.json` | Reusable workflow call context data |
+| `src/context-providers/descriptions.json` | Context variable descriptions for hover |
+
+### workflow-parser
+
+| File | Description |
+|------|-------------|
+| `src/workflow-v1.0.json` | Workflow YAML schema definition |
+
+## Generation
+
+### Webhooks and Objects
+
+The `webhooks.json` and `objects.json` files are generated from the [GitHub REST API description](https://github.com/github/rest-api-description):
+
+```bash
+cd languageservice
+npm run update-webhooks
+```
+
+This script:
+1. Fetches webhook schemas from the GitHub API description
+2. **Validates** all events are categorized (fails if new events are found)
+3. **Drops** events that aren't valid workflow triggers (see [Dropped Events](#dropped-events))
+4. **Strips** unused fields like `description` and `summary` (see [Stripped Fields](#stripped-fields))
+5. **Deduplicates** shared object definitions into `objects.json`
+6. Writes the optimized, pretty-printed JSON files
+
+### Handling New Webhook Events
+
+When GitHub adds a new webhook event, the script will fail with an error like:
+
+```
+ERROR: New webhook event(s) detected!
+
+The following events are not categorized:
+  - new_event_name
+
+Action required:
+  1. Check if the event is a valid workflow trigger
+  2. Add the event to DROPPED_EVENTS or KEPT_EVENTS
+```
+
+**To resolve:**
+
+1. Check [Events that trigger workflows](https://docs.github.com/en/actions/writing-workflows/choosing-when-your-workflow-runs/events-that-trigger-workflows)
+
+2. Edit `languageservice/script/webhooks/index.ts`:
+   - Add to `KEPT_EVENTS` if it's a valid workflow trigger
+   - Add to `DROPPED_EVENTS` if it's GitHub App or API-only
+
+3. Run `npm run update-webhooks` and commit the changes
+
+#### Viewing Full Unprocessed Data
+
+To see all available fields and events before optimization:
+
+```bash
+npm run update-webhooks -- --all
+```
+
+This generates `webhooks.all.json` and `objects.all.json` (gitignored) containing the complete unprocessed data from the GitHub API.
+
+### Other Files
+
+The other JSON files (`schedule.json`, `workflow_call.json`, `descriptions.json`, `workflow-v1.0.json`) are manually maintained.
+
+## Minification
+
+At build time, all JSON files are minified (whitespace removed) to produce `.min.json` versions:
+
+```bash
+npm run minify-json
+```
+
+This runs automatically via `prebuild` and `pretest` hooks, so you don't need to run it manually.
+
+The code imports the minified versions:
+
+```ts
+import webhooks from "./events/webhooks.min.json"
+```
+
+## CI Verification
+
+CI verifies that generated source files are up-to-date:
+
+1. Runs `npm run update-webhooks` to regenerate webhooks.json and objects.json
+2. Checks for uncommitted changes with `git diff --exit-code`
+
+The `.min.json` files are generated at build time and are not committed to the repository.
+
+If the build fails, run `cd languageservice && npm run update-webhooks` locally and commit the changes.
+
+## Dropped Events
+
+Webhook events that aren't valid workflow `on:` triggers are dropped (e.g., `installation`, `ping`, `member`, etc.). These are GitHub App or API-only events.
+
+See `DROPPED_EVENTS` in `script/webhooks/index.ts` for the full list.
+
+## Stripped Fields
+
+Unused fields are stripped to reduce bundle size. For example:
+
+```json
+// Before (from webhooks.all.json)
+{
+  "type": "object",
+  "name": "issue",
+  "in": "body",
+  "description": "The issue itself.",
+  "isRequired": true,
+  "childParamsGroups": [...]
+}
+
+// After (webhooks.json)
+{
+  "name": "issue",
+  "description": "The issue itself.",
+  "childParamsGroups": [...]
+}
+```
+
+Only `name`, `description`, and `childParamsGroups` are kept — these are used for autocompletion and hover docs.
+
+To compare all fields vs stripped, run `npm run update-webhooks -- --all` and diff the `.all.json` files against the regular ones.
+
+See `EVENT_ACTION_FIELDS` and `BODY_PARAM_FIELDS` in `script/webhooks/index.ts` to modify what gets stripped.
+
+## Schema Synchronization
+
+The `workflow-v1.0.json` schema defines which activity types are valid for each workflow trigger event. A test in `workflow-parser/src/schema-sync.test.ts` verifies these stay in sync with `webhooks.json`.
+
+### When the Test Fails
+
+If the schema-sync test fails, you'll see an error like:
+
+```
+Event "pull_request" is missing activity type "new_activity" in workflow-v1.0.json
+```
+
+**To resolve:**
+
+1. Check [Events that trigger workflows](https://docs.github.com/en/actions/writing-workflows/choosing-when-your-workflow-runs/events-that-trigger-workflows) to verify the activity type is a valid workflow trigger:
+   - Find the event section (e.g., "pull_request")
+   - Look at the "Activity types" table — it lists which types can be used in `on.<event>.types`
+   - If the type is listed there, it's a valid workflow trigger
+   - If the type only appears in webhook docs but NOT in the workflow trigger docs, it's webhook-only
+
+2. If it IS a valid workflow trigger:
+   - Edit `workflow-parser/src/workflow-v1.0.json`
+   - Find the `<event>-activity-type` definition (e.g., `pull-request-activity-type`)
+   - Add the new activity type to `allowed-values`
+   - Update the `description` in `<event>-activity` to list all types
+   - Run `npm test` to regenerate the minified JSON
+
+3. If it is NOT a valid workflow trigger (webhook-only):
+   - Edit `workflow-parser/src/schema-sync.test.ts`
+   - Add the type to `WEBHOOK_ONLY` for that event
+
+### Known Discrepancies
+
+The test tracks several types of known discrepancies:
+
+| Category | Purpose | Example |
+|----------|---------|---------|
+| `WEBHOOK_ONLY` | Types in webhooks that aren't valid workflow triggers | `check_suite.requested` |
+| `SCHEMA_ONLY` | Types valid for workflows but missing from webhooks | `registry_package.updated` |
+| `NAME_MAPPINGS` | Different names for the same concept | `project_column`: webhook uses `edited`, schema uses `updated` |
+
+### Bidirectional Checking
+
+The test checks both directions:
+- **webhooks → schema**: Ensures all webhook activity types are in the schema (or listed in `WEBHOOK_ONLY`)
+- **schema → webhooks**: Ensures the schema doesn't have types that don't exist in webhooks (or listed in `SCHEMA_ONLY` or `NAME_MAPPINGS`)

expressions/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@actions/expressions",
-  "version": "0.3.3",
+  "version": "0.3.35",
   "license": "MIT",
   "type": "module",
   "source": "./src/index.ts",
@@ -9,10 +9,12 @@
   },
   "exports": {
     ".": {
-      "import": "./dist/index.js"
+      "import": "./dist/index.js",
+      "types": "./dist/index.d.ts"
     },
     "./*": {
-      "import": "./dist/*.js"
+      "import": "./dist/*.js",
+      "types": "./dist/*.d.ts"
     }
   },
   "typesVersions": {
@@ -34,7 +36,7 @@
     "clean": "rimraf dist",
     "format": "prettier --write '**/*.ts'",
     "format-check": "prettier --check '**/*.ts'",
-    "lint": "eslint 'src/**/*.ts'",
+    "lint": "eslint --max-warnings 0 'src/**/*.ts'",
     "lint-fix": "eslint --fix 'src/**/*.ts'",
     "prepublishOnly": "npm run build && npm run test",
     "test": "NODE_OPTIONS=\"--experimental-vm-modules\" jest",
@@ -42,7 +44,7 @@
     "watch": "tsc --build tsconfig.build.json --watch"
   },
   "engines": {
-    "node": ">= 16.15"
+    "node": ">= 18"
   },
   "files": [
     "dist/**/*"
@@ -58,6 +60,6 @@
     "prettier": "^2.8.3",
     "rimraf": "^3.0.2",
     "ts-jest": "^29.0.3",
-    "typescript": "^4.7.4"
+    "typescript": "^5.8.3"
   }
 }

expressions/src/ast.ts

@@ -1,5 +1,5 @@
-import {ExpressionData} from "./data";
-import {Token} from "./lexer";
+import {ExpressionData} from "./data/index.js";
+import {Token} from "./lexer.js";
 
 export interface ExprVisitor<R> {
   visitLiteral(literal: Literal): R;

expressions/src/completion.test.ts

@@ -1,11 +1,11 @@
-import {complete, CompletionItem, trimTokenVector} from "./completion";
-import {DescriptionDictionary} from "./completion/descriptionDictionary";
-import {BooleanData} from "./data/boolean";
-import {Dictionary} from "./data/dictionary";
-import {StringData} from "./data/string";
-import {wellKnownFunctions} from "./funcs";
-import {FunctionDefinition, FunctionInfo} from "./funcs/info";
-import {Lexer, TokenType} from "./lexer";
+import {complete, CompletionItem, trimTokenVector} from "./completion.js";
+import {DescriptionDictionary} from "./completion/descriptionDictionary.js";
+import {BooleanData} from "./data/boolean.js";
+import {Dictionary} from "./data/dictionary.js";
+import {StringData} from "./data/string.js";
+import {wellKnownFunctions} from "./funcs.js";
+import {FunctionDefinition, FunctionInfo} from "./funcs/info.js";
+import {Lexer, TokenType} from "./lexer.js";
 
 const testContext = new Dictionary(
   {

expressions/src/completion.ts

@@ -1,11 +1,11 @@
-import {DescriptionPair} from "./completion/descriptionDictionary";
-import {Dictionary, isDictionary} from "./data/dictionary";
-import {ExpressionData} from "./data/expressiondata";
-import {Evaluator} from "./evaluator";
-import {wellKnownFunctions} from "./funcs";
-import {FunctionDefinition, FunctionInfo} from "./funcs/info";
-import {Lexer, Token, TokenType} from "./lexer";
-import {Parser} from "./parser";
+import {DescriptionPair} from "./completion/descriptionDictionary.js";
+import {Dictionary, isDictionary} from "./data/dictionary.js";
+import {ExpressionData} from "./data/expressiondata.js";
+import {Evaluator} from "./evaluator.js";
+import {wellKnownFunctions} from "./funcs.js";
+import {FunctionDefinition, FunctionInfo} from "./funcs/info.js";
+import {Lexer, Token, TokenType} from "./lexer.js";
+import {Parser} from "./parser.js";
 
 export type CompletionItem = {
   label: string;

expressions/src/completion/descriptionDictionary.test.ts

@@ -1,5 +1,5 @@
-import {StringData} from "../data";
-import {DescriptionDictionary} from "./descriptionDictionary";
+import {StringData} from "../data/index.js";
+import {DescriptionDictionary} from "./descriptionDictionary.js";
 
 describe("description dictionary", () => {
   it("pairs contains all values", () => {

expressions/src/completion/descriptionDictionary.ts

@@ -1,5 +1,5 @@
-import {Dictionary} from "../data/dictionary";
-import {ExpressionData, Kind, Pair} from "../data/expressiondata";
+import {Dictionary} from "../data/dictionary.js";
+import {ExpressionData, Kind, Pair} from "../data/expressiondata.js";
 
 export type DescriptionPair = Pair & {description?: string};
 

expressions/src/data/array.ts

@@ -1,4 +1,4 @@
-import {ExpressionData, ExpressionDataInterface, Kind, kindStr} from "./expressiondata";
+import {ExpressionData, ExpressionDataInterface, Kind, kindStr} from "./expressiondata.js";
 
 export class Array implements ExpressionDataInterface {
   private v: ExpressionData[] = [];

expressions/src/data/boolean.ts

@@ -1,4 +1,4 @@
-import {ExpressionDataInterface, Kind} from "./expressiondata";
+import {ExpressionDataInterface, Kind} from "./expressiondata.js";
 
 export class BooleanData implements ExpressionDataInterface {
   constructor(public readonly value: boolean) {}

expressions/src/data/dictionary.test.ts

@@ -1,5 +1,5 @@
-import {Dictionary} from "./dictionary";
-import {StringData} from "./string";
+import {Dictionary} from "./dictionary.js";
+import {StringData} from "./string.js";
 
 describe("dictionary", () => {
   it("pairs contains all values", () => {

expressions/src/data/dictionary.ts

@@ -1,4 +1,4 @@
-import {ExpressionData, ExpressionDataInterface, Kind, kindStr, Pair} from "./expressiondata";
+import {ExpressionData, ExpressionDataInterface, Kind, kindStr, Pair} from "./expressiondata.js";
 
 export class Dictionary implements ExpressionDataInterface {
   private keys: string[] = [];

expressions/src/data/expressiondata.ts

@@ -1,9 +1,9 @@
-import {Dictionary} from "./dictionary";
-import {Null} from "./null";
-import {Array} from "./array";
-import {StringData} from "./string";
-import {NumberData} from "./number";
-import {BooleanData} from "./boolean";
+import {Dictionary} from "./dictionary.js";
+import {Null} from "./null.js";
+import {Array} from "./array.js";
+import {StringData} from "./string.js";
+import {NumberData} from "./number.js";
+import {BooleanData} from "./boolean.js";
 
 export enum Kind {
   String = 0,

expressions/src/data/index.ts

@@ -1,9 +1,9 @@
-export {Array} from "./array";
-export {BooleanData} from "./boolean";
-export {Dictionary} from "./dictionary";
-export {ExpressionData, Kind} from "./expressiondata";
-export {Null} from "./null";
-export {NumberData} from "./number";
-export {replacer} from "./replacer";
-export {reviver} from "./reviver";
-export {StringData} from "./string";
+export {Array} from "./array.js";
+export {BooleanData} from "./boolean.js";
+export {Dictionary} from "./dictionary.js";
+export {ExpressionData, Kind} from "./expressiondata.js";
+export {Null} from "./null.js";
+export {NumberData} from "./number.js";
+export {replacer} from "./replacer.js";
+export {reviver} from "./reviver.js";
+export {StringData} from "./string.js";

expressions/src/data/null.ts

@@ -1,4 +1,4 @@
-import {ExpressionDataInterface, Kind} from "./expressiondata";
+import {ExpressionDataInterface, Kind} from "./expressiondata.js";
 
 export class Null implements ExpressionDataInterface {
   public readonly kind = Kind.Null;

expressions/src/data/number.test.ts

@@ -1,4 +1,4 @@
-import {NumberData} from "./number";
+import {NumberData} from "./number.js";
 
 describe("number", () => {
   it("coerces to string", () => {

expressions/src/data/number.ts

@@ -1,4 +1,4 @@
-import {ExpressionDataInterface, Kind} from "./expressiondata";
+import {ExpressionDataInterface, Kind} from "./expressiondata.js";
 
 export class NumberData implements ExpressionDataInterface {
   constructor(public readonly value: number) {}

expressions/src/data/replacer.test.ts

@@ -1,9 +1,9 @@
-import {Array} from "./array";
-import {Dictionary} from "./dictionary";
-import {Null} from "./null";
-import {NumberData} from "./number";
-import {replacer} from "./replacer";
-import {StringData} from "./string";
+import {Array} from "./array.js";
+import {Dictionary} from "./dictionary.js";
+import {Null} from "./null.js";
+import {NumberData} from "./number.js";
+import {replacer} from "./replacer.js";
+import {StringData} from "./string.js";
 
 describe("replacer", () => {
   it("null", () => {

expressions/src/data/replacer.ts

@@ -1,9 +1,9 @@
-import {Array} from "./array";
-import {BooleanData} from "./boolean";
-import {Dictionary} from "./dictionary";
-import {Null} from "./null";
-import {NumberData} from "./number";
-import {StringData} from "./string";
+import {Array} from "./array.js";
+import {BooleanData} from "./boolean.js";
+import {Dictionary} from "./dictionary.js";
+import {Null} from "./null.js";
+import {NumberData} from "./number.js";
+import {StringData} from "./string.js";
 
 /**
  * Replacer can be passed to JSON.stringify to convert an ExpressionData object into plain JSON

expressions/src/data/reviver.test.ts

@@ -1,11 +1,11 @@
-import {Array} from "./array";
-import {BooleanData} from "./boolean";
-import {Dictionary} from "./dictionary";
-import {ExpressionData} from "./expressiondata";
-import {Null} from "./null";
-import {NumberData} from "./number";
-import {reviver} from "./reviver";
-import {StringData} from "./string";
+import {Array} from "./array.js";
+import {BooleanData} from "./boolean.js";
+import {Dictionary} from "./dictionary.js";
+import {ExpressionData} from "./expressiondata.js";
+import {Null} from "./null.js";
+import {NumberData} from "./number.js";
+import {reviver} from "./reviver.js";
+import {StringData} from "./string.js";
 
 describe("reviver", () => {
   const tests: {

expressions/src/data/reviver.ts

@@ -1,10 +1,10 @@
-import {Array as dArray} from "./array";
-import {BooleanData} from "./boolean";
-import {Dictionary} from "./dictionary";
-import {ExpressionData} from "./expressiondata";
-import {Null} from "./null";
-import {NumberData} from "./number";
-import {StringData} from "./string";
+import {Array as dArray} from "./array.js";
+import {BooleanData} from "./boolean.js";
+import {Dictionary} from "./dictionary.js";
+import {ExpressionData} from "./expressiondata.js";
+import {Null} from "./null.js";
+import {NumberData} from "./number.js";
+import {StringData} from "./string.js";
 
 /**
  * Reviver can be passed to `JSON.parse` to convert plain JSON into an `ExpressionData` object.

expressions/src/data/string.ts

@@ -1,4 +1,4 @@
-import {ExpressionDataInterface, Kind} from "./expressiondata";
+import {ExpressionDataInterface, Kind} from "./expressiondata.js";
 
 export class StringData implements ExpressionDataInterface {
   constructor(public readonly value: string) {}

expressions/src/errors.ts

@@ -1,4 +1,4 @@
-import {Pos, Token, tokenString} from "./lexer";
+import {Pos, Token, tokenString} from "./lexer.js";
 
 export const MAX_PARSER_DEPTH = 50;
 export const MAX_EXPRESSION_LENGTH = 21000;

expressions/src/evaluator.test.ts

@@ -1,8 +1,8 @@
-import * as data from "./data";
-import {ExpressionEvaluationError} from "./errors";
-import {Evaluator} from "./evaluator";
-import {Lexer} from "./lexer";
-import {Parser} from "./parser";
+import * as data from "./data/index.js";
+import {ExpressionEvaluationError} from "./errors.js";
+import {Evaluator} from "./evaluator.js";
+import {Lexer} from "./lexer.js";
+import {Parser} from "./parser.js";
 
 describe("evaluator", () => {
   const lexAndParse = (input: string) => {

expressions/src/evaluator.ts

@@ -10,14 +10,14 @@ import {
   Logical,
   Star,
   Unary
-} from "./ast";
-import * as data from "./data";
-import {FilteredArray} from "./filtered_array";
-import {wellKnownFunctions} from "./funcs";
-import {FunctionDefinition} from "./funcs/info";
-import {idxHelper} from "./idxHelper";
-import {TokenType} from "./lexer";
-import {equals, falsy, greaterThan, lessThan, truthy} from "./result";
+} from "./ast.js";
+import * as data from "./data/index.js";
+import {FilteredArray} from "./filtered_array.js";
+import {wellKnownFunctions} from "./funcs.js";
+import {FunctionDefinition} from "./funcs/info.js";
+import {idxHelper} from "./idxHelper.js";
+import {TokenType} from "./lexer.js";
+import {equals, falsy, greaterThan, lessThan, truthy} from "./result.js";
 
 export class Evaluator implements ExprVisitor<data.ExpressionData> {
   /**

expressions/src/features.test.ts

@@ -0,0 +1,61 @@
+import {FeatureFlags} from "./features.js";
+
+describe("FeatureFlags", () => {
+  describe("isEnabled", () => {
+    it("returns false by default when no options provided", () => {
+      const flags = new FeatureFlags();
+      expect(flags.isEnabled("missingInputsQuickfix")).toBe(false);
+    });
+
+    it("returns false by default when empty options provided", () => {
+      const flags = new FeatureFlags({});
+      expect(flags.isEnabled("missingInputsQuickfix")).toBe(false);
+    });
+
+    it("returns true when feature is explicitly enabled", () => {
+      const flags = new FeatureFlags({missingInputsQuickfix: true});
+      expect(flags.isEnabled("missingInputsQuickfix")).toBe(true);
+    });
+
+    it("returns false when feature is explicitly disabled", () => {
+      const flags = new FeatureFlags({missingInputsQuickfix: false});
+      expect(flags.isEnabled("missingInputsQuickfix")).toBe(false);
+    });
+
+    it("returns true when all is enabled", () => {
+      const flags = new FeatureFlags({all: true});
+      expect(flags.isEnabled("missingInputsQuickfix")).toBe(true);
+    });
+
+    it("explicit feature flag takes precedence over all:true", () => {
+      const flags = new FeatureFlags({all: true, missingInputsQuickfix: false});
+      expect(flags.isEnabled("missingInputsQuickfix")).toBe(false);
+    });
+
+    it("explicit feature flag takes precedence over all:false", () => {
+      const flags = new FeatureFlags({all: false, missingInputsQuickfix: true});
+      expect(flags.isEnabled("missingInputsQuickfix")).toBe(true);
+    });
+  });
+
+  describe("getEnabledFeatures", () => {
+    it("returns empty array when no features enabled", () => {
+      const flags = new FeatureFlags();
+      expect(flags.getEnabledFeatures()).toEqual([]);
+    });
+
+    it("returns enabled features", () => {
+      const flags = new FeatureFlags({missingInputsQuickfix: true});
+      expect(flags.getEnabledFeatures()).toEqual(["missingInputsQuickfix"]);
+    });
+
+    it("returns all features when all is enabled", () => {
+      const flags = new FeatureFlags({all: true});
+      expect(flags.getEnabledFeatures()).toEqual([
+        "missingInputsQuickfix",
+        "blockScalarChompingWarning",
+        "actionScaffoldingSnippets"
+      ]);
+    });
+  });
+});

expressions/src/features.ts

@@ -0,0 +1,84 @@
+/**
+ * Experimental feature flags.
+ *
+ * Individual feature flags take precedence over `all`.
+ * Example: { all: true, missingInputsQuickfix: false } enables all
+ * experimental features EXCEPT missingInputsQuickfix.
+ *
+ * When a feature graduates to stable, its flag becomes a no-op
+ * (the feature will be enabled regardless of the configuration value).
+ */
+export interface ExperimentalFeatures {
+  /**
+   * Enable all experimental features.
+   * Individual feature flags take precedence over this setting.
+   * @default false
+   */
+  all?: boolean;
+
+  /**
+   * Enable quickfix code action for missing required action inputs.
+   * @default false
+   */
+  missingInputsQuickfix?: boolean;
+
+  /**
+   * Warn when block scalars (| or >) use implicit clip chomping,
+   * which adds a trailing newline that may be unintentional.
+   * @default false
+   */
+  blockScalarChompingWarning?: boolean;
+
+  /**
+   * Enable action scaffolding snippets in action.yml files.
+   * Offers Node.js, Composite, and Docker action scaffolds.
+   * @default false
+   */
+  actionScaffoldingSnippets?: boolean;
+}
+
+/**
+ * Keys of ExperimentalFeatures that represent actual features (excludes 'all')
+ */
+export type ExperimentalFeatureKey = Exclude<keyof ExperimentalFeatures, "all">;
+
+/**
+ * All known experimental feature keys.
+ * This list must be kept in sync with the ExperimentalFeatures interface.
+ */
+const allFeatureKeys: ExperimentalFeatureKey[] = [
+  "missingInputsQuickfix",
+  "blockScalarChompingWarning",
+  "actionScaffoldingSnippets"
+];
+
+export class FeatureFlags {
+  private readonly features: ExperimentalFeatures;
+
+  constructor(features?: ExperimentalFeatures) {
+    this.features = features ?? {};
+  }
+
+  /**
+   * Check if an experimental feature is enabled.
+   *
+   * Resolution order:
+   * 1. Explicit feature flag (if set)
+   * 2. `all` flag (if set)
+   * 3. false (default)
+   */
+  isEnabled(feature: ExperimentalFeatureKey): boolean {
+    const explicit = this.features[feature];
+    if (explicit !== undefined) {
+      return explicit;
+    }
+    return this.features.all ?? false;
+  }
+
+  /**
+   * Returns list of all enabled experimental features.
+   */
+  getEnabledFeatures(): ExperimentalFeatureKey[] {
+    return allFeatureKeys.filter(key => this.isEnabled(key));
+  }
+}

expressions/src/filtered_array.ts

@@ -1,3 +1,3 @@
-import * as data from "./data";
+import * as data from "./data/index.js";
 
 export class FilteredArray extends data.Array {}

expressions/src/funcs.ts

@@ -1,13 +1,13 @@
-import {ErrorType, ExpressionError} from "./errors";
-import {contains} from "./funcs/contains";
-import {endswith} from "./funcs/endswith";
-import {format} from "./funcs/format";
-import {fromjson} from "./funcs/fromjson";
-import {FunctionDefinition, FunctionInfo} from "./funcs/info";
-import {join} from "./funcs/join";
-import {startswith} from "./funcs/startswith";
-import {tojson} from "./funcs/tojson";
-import {Token} from "./lexer";
+import {ErrorType, ExpressionError} from "./errors.js";
+import {contains} from "./funcs/contains.js";
+import {endswith} from "./funcs/endswith.js";
+import {format} from "./funcs/format.js";
+import {fromjson} from "./funcs/fromjson.js";
+import {FunctionDefinition, FunctionInfo} from "./funcs/info.js";
+import {join} from "./funcs/join.js";
+import {startswith} from "./funcs/startswith.js";
+import {tojson} from "./funcs/tojson.js";
+import {Token} from "./lexer.js";
 
 export type ParseContext = {
   allowUnknownKeywords: boolean;

expressions/src/funcs/contains.ts

@@ -1,6 +1,6 @@
-import {BooleanData, ExpressionData, Kind} from "../data";
-import {equals} from "../result";
-import {FunctionDefinition} from "./info";
+import {BooleanData, ExpressionData, Kind} from "../data/index.js";
+import {equals} from "../result.js";
+import {FunctionDefinition} from "./info.js";
 
 export const contains: FunctionDefinition = {
   name: "contains",

expressions/src/funcs/endswith.ts

@@ -1,6 +1,6 @@
-import {BooleanData, ExpressionData} from "../data";
-import {toUpperSpecial} from "../result";
-import {FunctionDefinition} from "./info";
+import {BooleanData, ExpressionData} from "../data/index.js";
+import {toUpperSpecial} from "../result.js";
+import {FunctionDefinition} from "./info.js";
 
 export const endswith: FunctionDefinition = {
   name: "endsWith",

expressions/src/funcs/format.test.ts

@@ -1,5 +1,5 @@
-import {Null, NumberData, StringData} from "../data";
-import {format} from "./format";
+import {Null, NumberData, StringData} from "../data/index.js";
+import {format} from "./format.js";
 
 describe("format", () => {
   it("null", () => {

expressions/src/funcs/format.ts

@@ -1,5 +1,5 @@
-import {ExpressionData, StringData} from "../data";
-import {FunctionDefinition} from "./info";
+import {ExpressionData, StringData} from "../data/index.js";
+import {FunctionDefinition} from "./info.js";
 
 export const format: FunctionDefinition = {
   name: "format",

expressions/src/funcs/fromjson.ts

@@ -1,7 +1,7 @@
-import {ExpressionData} from "../data";
-import {reviver} from "../data/reviver";
-import {ExpressionEvaluationError} from "../errors";
-import {FunctionDefinition} from "./info";
+import {ExpressionData} from "../data/index.js";
+import {reviver} from "../data/reviver.js";
+import {ExpressionEvaluationError} from "../errors.js";
+import {FunctionDefinition} from "./info.js";
 
 export const fromjson: FunctionDefinition = {
   name: "fromJson",

expressions/src/funcs/info.ts

@@ -1,4 +1,4 @@
-import {ExpressionData} from "../data";
+import {ExpressionData} from "../data/index.js";
 
 export interface FunctionInfo {
   name: string;

expressions/src/funcs/join.ts

@@ -1,5 +1,5 @@
-import {ExpressionData, Kind, StringData} from "../data";
-import {FunctionDefinition} from "./info";
+import {ExpressionData, Kind, StringData} from "../data/index.js";
+import {FunctionDefinition} from "./info.js";
 
 export const join: FunctionDefinition = {
   name: "join",

expressions/src/funcs/startswith.ts

@@ -1,6 +1,6 @@
-import {BooleanData, ExpressionData} from "../data";
-import {toUpperSpecial} from "../result";
-import {FunctionDefinition} from "./info";
+import {BooleanData, ExpressionData} from "../data/index.js";
+import {toUpperSpecial} from "../result.js";
+import {FunctionDefinition} from "./info.js";
 
 export const startswith: FunctionDefinition = {
   name: "startsWith",

expressions/src/funcs/tojson.ts

@@ -1,6 +1,6 @@
-import {ExpressionData, StringData} from "../data";
-import {replacer} from "../data/replacer";
-import {FunctionDefinition} from "./info";
+import {ExpressionData, StringData} from "../data/index.js";
+import {replacer} from "../data/replacer.js";
+import {FunctionDefinition} from "./info.js";
 
 export const tojson: FunctionDefinition = {
   name: "toJson",

expressions/src/idxHelper.ts

@@ -1,4 +1,4 @@
-import {ExpressionData} from "./data";
+import {ExpressionData} from "./data/index.js";
 
 export class idxHelper {
   public readonly str: string | undefined;

expressions/src/index.ts

@@ -1,9 +1,10 @@
-export {Expr} from "./ast";
-export {complete, CompletionItem} from "./completion";
-export {DescriptionDictionary, DescriptionPair, isDescriptionDictionary} from "./completion/descriptionDictionary";
-export * as data from "./data";
-export {ExpressionError, ExpressionEvaluationError} from "./errors";
-export {Evaluator} from "./evaluator";
-export {wellKnownFunctions} from "./funcs";
-export {Lexer, Result} from "./lexer";
-export {Parser} from "./parser";
+export {Expr} from "./ast.js";
+export {complete, CompletionItem} from "./completion.js";
+export {DescriptionDictionary, DescriptionPair, isDescriptionDictionary} from "./completion/descriptionDictionary.js";
+export * as data from "./data/index.js";
+export {ExpressionError, ExpressionEvaluationError} from "./errors.js";
+export {Evaluator} from "./evaluator.js";
+export {ExperimentalFeatureKey, ExperimentalFeatures, FeatureFlags} from "./features.js";
+export {wellKnownFunctions} from "./funcs.js";
+export {Lexer, Result} from "./lexer.js";
+export {Parser} from "./parser.js";

expressions/src/lexer.test.ts

@@ -1,4 +1,4 @@
-import {Lexer, Token, TokenType} from "./lexer";
+import {Lexer, Token, TokenType} from "./lexer.js";
 
 describe("lexer", () => {
   const tests: {

expressions/src/lexer.ts

@@ -1,5 +1,5 @@
-import {StringData} from "./data";
-import {MAX_EXPRESSION_LENGTH} from "./errors";
+import {StringData} from "./data/index.js";
+import {MAX_EXPRESSION_LENGTH} from "./errors.js";
 
 export enum TokenType {
   UNKNOWN,

expressions/src/parser.ts

@@ -1,9 +1,20 @@
-import {Binary, ContextAccess, Expr, FunctionCall, Grouping, IndexAccess, Literal, Logical, Star, Unary} from "./ast";
-import * as data from "./data";
-import {ErrorType, ExpressionError, MAX_PARSER_DEPTH} from "./errors";
-import {ParseContext, validateFunction} from "./funcs";
-import {FunctionInfo} from "./funcs/info";
-import {Token, TokenType} from "./lexer";
+import {
+  Binary,
+  ContextAccess,
+  Expr,
+  FunctionCall,
+  Grouping,
+  IndexAccess,
+  Literal,
+  Logical,
+  Star,
+  Unary
+} from "./ast.js";
+import * as data from "./data/index.js";
+import {ErrorType, ExpressionError, MAX_PARSER_DEPTH} from "./errors.js";
+import {ParseContext, validateFunction} from "./funcs.js";
+import {FunctionInfo} from "./funcs/info.js";
+import {Token, TokenType} from "./lexer.js";
 
 export class Parser {
   private extContexts: Map<string, boolean>;

expressions/src/result.test.ts

@@ -1,5 +1,5 @@
-import {BooleanData, ExpressionData, NumberData, StringData} from "./data";
-import {coerceTypes, toUpperSpecial} from "./result";
+import {BooleanData, ExpressionData, NumberData, StringData} from "./data/index.js";
+import {coerceTypes, toUpperSpecial} from "./result.js";
 
 describe("coerceTypes", () => {
   const tests: {

expressions/src/result.ts

@@ -1,4 +1,4 @@
-import * as data from "./data";
+import * as data from "./data/index.js";
 
 export function falsy(d: data.ExpressionData): boolean {
   switch (d.kind) {

expressions/src/xlang.test.ts

@@ -1,14 +1,14 @@
 import * as fs from "fs";
 import * as path from "path";
-import {Expr} from "./ast";
-import * as data from "./data";
-import {kindStr} from "./data/expressiondata";
-import {replacer} from "./data/replacer";
-import {reviver} from "./data/reviver";
-import {ExpressionError} from "./errors";
-import {Evaluator} from "./evaluator";
-import {Lexer, Result} from "./lexer";
-import {Parser} from "./parser";
+import {Expr} from "./ast.js";
+import * as data from "./data/index.js";
+import {kindStr} from "./data/expressiondata.js";
+import {replacer} from "./data/replacer.js";
+import {reviver} from "./data/reviver.js";
+import {ExpressionError} from "./errors.js";
+import {Evaluator} from "./evaluator.js";
+import {Lexer, Result} from "./lexer.js";
+import {Parser} from "./parser.js";
 
 interface TestResult {
   value: data.ExpressionData;

expressions/tsconfig.build.json

@@ -2,9 +2,12 @@
   "exclude": ["./src/**/*.test.ts"],
   "extends": "./tsconfig.json",
   "compilerOptions": {
+    "module": "node16",
+    "moduleResolution": "node16",
     "declaration": true,
     "declarationMap": true,
     "noEmit": false,
-    "outDir": "./dist"
+    "outDir": "./dist",
+    "skipLibCheck": true
   }
 }

languageserver/README.md

@@ -10,6 +10,14 @@ The [package](https://www.npmjs.com/package/@actions/languageserver) contains Ty
 npm install @actions/languageserver
 ```
 
+To install the language server as a standalone CLI:
+
+```bash
+npm install -g @actions/languageserver
+```
+
+This makes the `actions-languageserver` command available globally.
+
 ## Usage
 
 ### Basic usage using `vscode-languageserver-node`
@@ -76,6 +84,11 @@ export interface InitializationOptions {
    * Desired log level
    */
   logLevel?: LogLevel;
+
+  /**
+   * Experimental features that are opt-in
+   */
+  experimentalFeatures?: ExperimentalFeatures;
 }
 ```
 
@@ -92,6 +105,177 @@ const clientOptions: LanguageClientOptions = {
 const client = new LanguageClient("actions-language", "GitHub Actions Language Server", serverOptions, clientOptions);
 ```
 
+### Experimental Features
+
+The language server supports opt-in experimental features via the `experimentalFeatures` initialization option. These features may change or be removed in between releases.
+
+```typescript
+initializationOptions: {
+  experimentalFeatures: {
+    // Enable all experimental features
+    all: true,
+
+    // Or enable specific features
+    missingInputsQuickfix: true,
+  }
+}
+```
+
+**Available experimental features:**
+
+| Feature | Description |
+|---------|-------------|
+| `missingInputsQuickfix` | Code action to add missing required inputs for actions |
+| `blockScalarChompingWarning` | Warn when block scalars (`\|` or `>`) use implicit clip chomping, which adds a trailing newline that may be unintentional |
+
+Individual feature flags take precedence over `all`. For example, `{ all: true, missingInputsQuickfix: false }` enables all experimental features except `missingInputsQuickfix`.
+
+When a feature graduates to stable, its flag becomes a no-op and the feature will be enabled regardless of the configuration value.
+
+### Standalone CLI
+
+After installing globally, you can run the language server directly:
+
+```bash
+actions-languageserver --stdio
+```
+
+This starts the language server using stdio transport, which is the standard way for editors to communicate with language servers.
+
+### In Neovim
+
+#### 1. Install the language server
+
+```bash
+npm install -g @actions/languageserver
+```
+
+#### 2. Set up filetype detection
+
+Add this to your `init.lua` to detect GitHub Actions workflow files:
+
+```lua
+vim.filetype.add({
+  pattern = {
+    [".*/%.github/workflows/.*%.ya?ml"] = "yaml.ghactions",
+  },
+})
+```
+
+This sets the filetype to `yaml.ghactions` for YAML files in `.github/workflows/`, allowing you to keep separate YAML LSP configurations if needed.
+
+#### 3. Create the LSP configuration
+
+As of Neovim 0.11+ you can add this configuration in `~/.config/nvim/lsp/actionsls.lua`:
+
+```lua
+local function get_github_token()
+  local handle = io.popen("gh auth token 2>/dev/null")
+  if not handle then return nil end
+  local token = handle: read("*a"):gsub("%s+", "")
+  handle:close()
+  return token ~= "" and token or nil
+end
+
+local function parse_github_remote(url)
+  if not url or url == "" then return nil end
+
+  -- SSH format: git@github.com:owner/repo.git
+  local owner, repo = url:match("git@github%.com:([^/]+)/([^/%.]+)")
+  if owner and repo then
+    return owner, repo: gsub("%.git$", "")
+  end
+
+  -- HTTPS format: https://github.com/owner/repo.git
+  owner, repo = url:match("github%.com/([^/]+)/([^/%.]+)")
+  if owner and repo then
+    return owner, repo:gsub("%.git$", "")
+  end
+
+  return nil
+end
+
+local function get_repo_info(owner, repo)
+  local cmd = string.format(
+    "gh repo view %s/%s --json id,owner --template '{{.id}}\t{{.owner.type}}' 2>/dev/null",
+    owner,
+    repo
+  )
+  local handle = io.popen(cmd)
+  if not handle then return nil end
+  local result = handle: read("*a"):gsub("%s+$", "")
+  handle:close()
+
+  local id, owner_type = result:match("^(%d+)\t(.+)$")
+  if id then
+    return {
+      id = tonumber(id),
+      organizationOwned = owner_type == "Organization",
+    }
+  end
+  return nil
+end
+
+local function get_repos_config()
+  local handle = io.popen("git rev-parse --show-toplevel 2>/dev/null")
+  if not handle then return nil end
+  local git_root = handle: read("*a"):gsub("%s+", "")
+  handle:close()
+
+  if git_root == "" then return nil end
+
+  handle = io.popen("git remote get-url origin 2>/dev/null")
+  if not handle then return nil end
+  local remote_url = handle:read("*a"):gsub("%s+", "")
+  handle:close()
+
+  local owner, name = parse_github_remote(remote_url)
+  if not owner or not name then return nil end
+
+  local info = get_repo_info(owner, name)
+
+  return {
+    {
+      id = info and info.id or 0,
+      owner = owner,
+      name = name,
+      organizationOwned = info and info.organizationOwned or false,
+      workspaceUri = "file://" .. git_root,
+    },
+  }
+end
+
+return {
+  cmd = { "actions-languageserver", "--stdio" },
+  filetypes = { "yaml.ghactions" },
+  root_markers = { ".git" },
+  init_options = {
+    -- Optional: provide a GitHub token and repo context for added functionality
+    -- (e.g., repository-specific completions)
+    sessionToken = get_github_token(),
+    repos = get_repos_config(),
+  },
+}
+```
+
+#### 4. Enable the LSP
+
+Add to your `init.lua`:
+
+```lua
+vim.lsp.enable('actionsls')
+```
+
+#### 5. Verify it's working
+
+Open any `.github/workflows/*.yml` file and run:
+
+```vim
+:checkhealth vim.lsp
+```
+
+You should see `actionsls` in the list of attached clients.
+
 ## Contributing
 
 See [CONTRIBUTING.md](../CONTRIBUTING.md) at the root of the repository for general guidelines and recommendations.
@@ -110,6 +294,27 @@ or to watch for changes
 npm run watch
 ```
 
+### Running the language server locally
+
+After running
+
+```bash
+npm run build:cli
+npm link
+```
+
+`actions-languageserver` will be available globally. You can start it with:
+
+```bash
+actions-languageserver --stdio
+```
+
+Once linked you can also watch for changes and rebuild automatically:
+
+```bash
+npm run watch:cli
+```
+
 ### Test
 
 ```bash

languageserver/bin/actions-languageserver

@@ -0,0 +1,2 @@
+#!/usr/bin/env node
+import "../dist/cli.bundle.cjs";

languageserver/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@actions/languageserver",
-  "version": "0.3.3",
+  "version": "0.3.35",
   "description": "Language server for GitHub Actions",
   "license": "MIT",
   "type": "module",
@@ -31,36 +31,43 @@
     "url": "https://github.com/actions/languageservices"
   },
   "scripts": {
-    "build": "tsc --build tsconfig.build.json",
+    "build": "tsc --build tsconfig.build.json && npm run build:cli",
+    "build:cli": "esbuild src/index.ts --bundle --platform=node --format=cjs --outfile=dist/cli.bundle.cjs",
     "clean": "rimraf dist",
     "format": "prettier --write '**/*.ts'",
     "format-check": "prettier --check '**/*.ts'",
-    "lint": "eslint 'src/**/*.ts'",
+    "lint": "eslint --max-warnings 0 'src/**/*.ts'",
     "lint-fix": "eslint --fix 'src/**/*.ts'",
     "prepublishOnly": "npm run build && npm run test",
     "test": "NODE_OPTIONS=\"--experimental-vm-modules\" jest",
     "test-watch": "NODE_OPTIONS=\"--experimental-vm-modules\" jest --watch",
-    "watch": "tsc --build tsconfig.build.json --watch"
+    "watch": "tsc --build tsconfig.build.json --watch",
+    "watch:cli": "esbuild src/index.ts --bundle --platform=node --format=cjs --outfile=dist/cli.bundle.cjs --watch"
+  },
+  "bin": {
+    "actions-languageserver": "./bin/actions-languageserver"
   },
   "dependencies": {
-    "@actions/languageservice": "^0.3.3",
-    "@actions/workflow-parser": "^0.3.3",
-    "@octokit/rest": "^19.0.7",
+    "@actions/languageservice": "^0.3.35",
+    "@actions/workflow-parser": "^0.3.35",
+    "@octokit/rest": "^21.1.1",
     "@octokit/types": "^9.0.0",
     "vscode-languageserver": "^8.0.2",
     "vscode-languageserver-textdocument": "^1.0.7",
     "yaml": "^2.1.3"
   },
   "engines": {
-    "node": ">= 16.15"
+    "node": ">= 18"
   },
   "files": [
-    "dist/**/*"
+    "dist/**/*",
+    "bin/**/*"
   ],
   "devDependencies": {
     "@types/jest": "^29.0.3",
     "@typescript-eslint/eslint-plugin": "^5.56.0",
     "@typescript-eslint/parser": "^5.56.0",
+    "esbuild": "^0.27.1",
     "eslint": "^8.36.0",
     "eslint-config-prettier": "^8.8.0",
     "eslint-plugin-prettier": "^4.2.1",

languageserver/src/client.ts

@@ -1,8 +1,9 @@
 import {Octokit} from "@octokit/rest";
 
-export function getClient(token: string, userAgent?: string): Octokit {
+export function getClient(token: string, userAgent?: string, apiUrl?: string): Octokit {
   return new Octokit({
     auth: token,
-    userAgent: userAgent || `GitHub Actions Language Server`
+    userAgent: userAgent || `GitHub Actions Language Server`,
+    baseUrl: apiUrl
   });
 }

languageserver/src/connection.ts

@@ -1,4 +1,4 @@
-import {documentLinks, hover, validate, ValidationConfig} from "@actions/languageservice";
+import {documentLinks, getInlayHints, hover, validate, ValidationConfig} from "@actions/languageservice";
 import {registerLogger, setLogLevel} from "@actions/languageservice/log";
 import {clearCache, clearCacheEntry} from "@actions/languageservice/utils/workflow-cache";
 import {Octokit} from "@octokit/rest";
@@ -12,24 +12,27 @@ import {
   HoverParams,
   InitializeParams,
   InitializeResult,
+  InlayHint,
+  InlayHintParams,
   TextDocumentIdentifier,
   TextDocumentPositionParams,
   TextDocuments,
   TextDocumentSyncKind
 } from "vscode-languageserver";
 import {TextDocument} from "vscode-languageserver-textdocument";
-import {getClient} from "./client";
-import {Commands} from "./commands";
-import {contextProviders} from "./context-providers";
-import {descriptionProvider} from "./description-provider";
-import {getFileProvider} from "./file-provider";
-import {InitializationOptions, RepositoryContext} from "./initializationOptions";
-import {onCompletion} from "./on-completion";
-import {ReadFileRequest, Requests} from "./request";
-import {getActionsMetadataProvider} from "./utils/action-metadata";
-import {TTLCache} from "./utils/cache";
-import {timeOperation} from "./utils/timer";
-import {valueProviders} from "./value-providers";
+import {getClient} from "./client.js";
+import {Commands} from "./commands.js";
+import {contextProviders} from "./context-providers.js";
+import {descriptionProvider} from "./description-provider.js";
+import {FeatureFlags} from "@actions/expressions";
+import {getFileProvider} from "./file-provider.js";
+import {InitializationOptions, RepositoryContext} from "./initializationOptions.js";
+import {onCompletion} from "./on-completion.js";
+import {ReadFileRequest, Requests} from "./request.js";
+import {getActionsMetadataProvider} from "./utils/action-metadata.js";
+import {TTLCache} from "./utils/cache.js";
+import {timeOperation} from "./utils/timer.js";
+import {valueProviders} from "./value-providers.js";
 
 export function initConnection(connection: Connection) {
   const documents: TextDocuments<TextDocument> = new TextDocuments(TextDocument);
@@ -39,6 +42,7 @@ export function initConnection(connection: Connection) {
   const cache = new TTLCache();
 
   let hasWorkspaceFolderCapability = false;
+  let featureFlags = new FeatureFlags();
 
   // Register remote console logger with language service
   registerLogger(connection.console);
@@ -51,7 +55,7 @@ export function initConnection(connection: Connection) {
     const options = params.initializationOptions as InitializationOptions;
 
     if (options.sessionToken) {
-      client = getClient(options.sessionToken, options.userAgent);
+      client = getClient(options.sessionToken, options.userAgent, options.gitHubApiUrl);
     }
 
     if (options.repos) {
@@ -62,6 +66,8 @@ export function initConnection(connection: Connection) {
       setLogLevel(options.logLevel);
     }
 
+    featureFlags = new FeatureFlags(options.experimentalFeatures);
+
     const result: InitializeResult = {
       capabilities: {
         textDocumentSync: TextDocumentSyncKind.Full,
@@ -72,7 +78,8 @@ export function initConnection(connection: Connection) {
         hoverProvider: true,
         documentLinkProvider: {
           resolveProvider: false
-        }
+        },
+        inlayHintProvider: true
       }
     };
 
@@ -88,6 +95,11 @@ export function initConnection(connection: Connection) {
   });
 
   connection.onInitialized(() => {
+    const enabledFeatures = featureFlags.getEnabledFeatures();
+    if (enabledFeatures.length > 0) {
+      connection.console.info(`Experimental features enabled: ${enabledFeatures.join(", ")}`);
+    }
+
     if (hasWorkspaceFolderCapability) {
       connection.workspace.onDidChangeWorkspaceFolders(() => {
         clearCache();
@@ -111,7 +123,8 @@ export function initConnection(connection: Connection) {
       actionsMetadataProvider: getActionsMetadataProvider(client, cache),
       fileProvider: getFileProvider(client, cache, repoContext?.workspaceUri, async path => {
         return await connection.sendRequest(Requests.ReadFile, {path} satisfies ReadFileRequest);
-      })
+      }),
+      featureFlags
     };
 
     const result = await validate(textDocument, config);
@@ -158,6 +171,12 @@ export function initConnection(connection: Connection) {
     return documentLinks(getDocument(documents, textDocument), repoContext?.workspaceUri);
   });
 
+  connection.languages.inlayHint.on(async ({textDocument}: InlayHintParams): Promise<InlayHint[] | null> => {
+    return timeOperation("inlayHints", () => {
+      return getInlayHints(getDocument(documents, textDocument));
+    });
+  });
+
   // Make the text document manager listen on the connection
   // for open, change and close text document events
   documents.listen(connection);

languageserver/src/context-providers.test.ts

@@ -0,0 +1,76 @@
+import {data, DescriptionDictionary} from "@actions/expressions";
+import {WorkflowContext} from "@actions/languageservice/context/workflow-context";
+import {Mode} from "@actions/languageservice/context-providers/default";
+import {contextProviders} from "./context-providers.js";
+import {RepositoryContext} from "./initializationOptions.js";
+import {TTLCache} from "./utils/cache.js";
+
+describe("contextProviders", () => {
+  const mockCache = new TTLCache();
+  const mockRepo: RepositoryContext = {
+    id: 123,
+    owner: "test-owner",
+    name: "test-repo",
+    organizationOwned: true,
+    workspaceUri: "file:///workspace"
+  };
+  const mockWorkflowContext: WorkflowContext = {
+    uri: "test.yaml",
+    template: undefined
+  };
+
+  describe("when client is undefined", () => {
+    it("should return incomplete context for secrets", async () => {
+      const config = contextProviders(undefined, mockRepo, mockCache);
+      const result = await config.getContext("secrets", undefined, mockWorkflowContext, Mode.Validation);
+
+      expect(result).toBeInstanceOf(DescriptionDictionary);
+      expect((result as DescriptionDictionary).complete).toBe(false);
+    });
+
+    it("should return incomplete context for vars", async () => {
+      const config = contextProviders(undefined, mockRepo, mockCache);
+      const result = await config.getContext("vars", undefined, mockWorkflowContext, Mode.Validation);
+
+      expect(result).toBeInstanceOf(DescriptionDictionary);
+      expect((result as DescriptionDictionary).complete).toBe(false);
+    });
+
+    it("should preserve defaultContext and mark as incomplete for secrets", async () => {
+      const config = contextProviders(undefined, mockRepo, mockCache);
+      const defaultContext = new DescriptionDictionary();
+      defaultContext.add("EXISTING_SECRET", new data.StringData("test"));
+
+      const result = await config.getContext("secrets", defaultContext, mockWorkflowContext, Mode.Validation);
+
+      expect(result).toBe(defaultContext);
+      expect((result as DescriptionDictionary).complete).toBe(false);
+      expect((result as DescriptionDictionary).get("EXISTING_SECRET")).toBeDefined();
+    });
+
+    it("should return undefined for other contexts like steps", async () => {
+      const config = contextProviders(undefined, mockRepo, mockCache);
+      const result = await config.getContext("steps", undefined, mockWorkflowContext, Mode.Validation);
+
+      expect(result).toBeUndefined();
+    });
+  });
+
+  describe("when both client and repo are undefined", () => {
+    it("should return incomplete context for secrets", async () => {
+      const config = contextProviders(undefined, undefined, mockCache);
+      const result = await config.getContext("secrets", undefined, mockWorkflowContext, Mode.Validation);
+
+      expect(result).toBeInstanceOf(DescriptionDictionary);
+      expect((result as DescriptionDictionary).complete).toBe(false);
+    });
+
+    it("should return incomplete context for vars", async () => {
+      const config = contextProviders(undefined, undefined, mockCache);
+      const result = await config.getContext("vars", undefined, mockWorkflowContext, Mode.Validation);
+
+      expect(result).toBeInstanceOf(DescriptionDictionary);
+      expect((result as DescriptionDictionary).complete).toBe(false);
+    });
+  });
+});

languageserver/src/context-providers.ts

@@ -3,11 +3,11 @@ import {ContextProviderConfig} from "@actions/languageservice";
 import {Mode} from "@actions/languageservice/context-providers/default";
 import {WorkflowContext} from "@actions/languageservice/context/workflow-context";
 import {Octokit} from "@octokit/rest";
-import {getSecrets} from "./context-providers/secrets";
-import {getStepsContext} from "./context-providers/steps";
-import {getVariables} from "./context-providers/variables";
-import {RepositoryContext} from "./initializationOptions";
-import {TTLCache} from "./utils/cache";
+import {getSecrets} from "./context-providers/secrets.js";
+import {getStepsContext} from "./context-providers/steps.js";
+import {getVariables} from "./context-providers/variables.js";
+import {RepositoryContext} from "./initializationOptions.js";
+import {TTLCache} from "./utils/cache.js";
 
 export function contextProviders(
   client: Octokit | undefined,
@@ -15,7 +15,18 @@ export function contextProviders(
   cache: TTLCache
 ): ContextProviderConfig {
   if (!repo || !client) {
-    return {getContext: () => Promise.resolve(undefined)};
+    // When GitHub client/repo is unavailable, return an incomplete dictionary
+    // to avoid false "Context access might be invalid" warnings
+    return {
+      getContext: (name: string, defaultContext: DescriptionDictionary | undefined) => {
+        if (name === "secrets" || name === "vars") {
+          const context = defaultContext || new DescriptionDictionary();
+          context.complete = false;
+          return Promise.resolve(context);
+        }
+        return Promise.resolve(undefined);
+      }
+    };
   }
 
   const getContext = async (

languageserver/src/context-providers/action-outputs.ts

@@ -1,7 +1,7 @@
 import {ActionOutputs, ActionReference} from "@actions/languageservice/action";
 import {Octokit} from "@octokit/rest";
-import {fetchActionMetadata} from "../utils/action-metadata";
-import {TTLCache} from "../utils/cache";
+import {fetchActionMetadata} from "../utils/action-metadata.js";
+import {TTLCache} from "../utils/cache.js";
 
 export async function getActionOutputs(
   octokit: Octokit,

languageserver/src/context-providers/secrets.ts

@@ -6,10 +6,10 @@ import {warn} from "@actions/languageservice/log";
 import {isMapping, isString} from "@actions/workflow-parser";
 import {Octokit} from "@octokit/rest";
 
-import {RepositoryContext} from "../initializationOptions";
-import {TTLCache} from "../utils/cache";
-import {errorStatus} from "../utils/error";
-import {getRepoPermission} from "../utils/repo-permission";
+import {RepositoryContext} from "../initializationOptions.js";
+import {TTLCache} from "../utils/cache.js";
+import {errorStatus} from "../utils/error.js";
+import {getRepoPermission} from "../utils/repo-permission.js";
 
 export async function getSecrets(
   workflowContext: WorkflowContext,
@@ -28,6 +28,7 @@ export async function getSecrets(
   }
 
   const eventsConfig = workflowContext?.template?.events;
+
   if (eventsConfig?.workflow_call) {
     // Unpredictable secrets may be passed in via a workflow_call trigger
     secretsContext.complete = false;
@@ -38,6 +39,7 @@ export async function getSecrets(
   }
 
   let environmentName: string | undefined;
+
   if (workflowContext?.job?.environment) {
     if (isString(workflowContext.job.environment)) {
       environmentName = workflowContext.job.environment.value;
@@ -46,10 +48,17 @@ export async function getSecrets(
         if (isString(x.key) && x.key.value === "name") {
           if (isString(x.value)) {
             environmentName = x.value.value;
+          } else {
+            // this means we have a dynamic environment, in those situations we
+            // want to make sure we skip doing secret validation
+            secretsContext.complete = false;
           }
           break;
         }
       }
+    } else {
+      // if the expression is something like environment: ${{ ... }} then we want to skip validation
+      secretsContext.complete = false;
     }
   }
 
@@ -116,7 +125,7 @@ async function getRemoteSecrets(
     environmentSecrets:
       (environmentName &&
         (await cache.get(`${repo.owner}/${repo.name}/secrets/environment/${environmentName}`, undefined, () =>
-          fetchEnvironmentSecrets(octokit, repo.id, environmentName)
+          fetchEnvironmentSecrets(octokit, repo.owner, repo.name, environmentName)
         ))) ||
       [],
     orgSecrets: await cache.get(`${repo.owner}/secrets`, undefined, () => fetchOrganizationSecrets(octokit, repo))
@@ -142,14 +151,16 @@ async function fetchSecrets(octokit: Octokit, owner: string, name: string): Prom
 
 async function fetchEnvironmentSecrets(
   octokit: Octokit,
-  repositoryId: number,
+  owner: string,
+  name: string,
   environmentName: string
 ): Promise<StringData[]> {
   try {
     return await octokit.paginate(
       octokit.actions.listEnvironmentSecrets,
       {
-        repository_id: repositoryId,
+        owner,
+        repo: name,
         environment_name: environmentName,
         per_page: 100
       },

languageserver/src/context-providers/steps.test.ts

@@ -1,11 +1,11 @@
-import {data, DescriptionDictionary} from "@actions/expressions";
+import {data, DescriptionDictionary, isDescriptionDictionary} from "@actions/expressions";
 import {getStepsContext as getDefaultStepsContext} from "@actions/languageservice/context-providers/steps";
 import {Octokit} from "@octokit/rest";
 import fetchMock from "fetch-mock";
 
-import {createWorkflowContext} from "../test-utils/workflow-context";
-import {TTLCache} from "../utils/cache";
-import {getStepsContext} from "./steps";
+import {createWorkflowContext} from "../test-utils/workflow-context.js";
+import {TTLCache} from "../utils/cache.js";
+import {getStepsContext} from "./steps.js";
 
 const workflow = `
 name: Caching Primes
@@ -63,6 +63,47 @@ it("returns default context when job is undefined", async () => {
   expect(stepsContext).toEqual(defaultContext);
 });
 
+it("outputs is an incomplete dictionary to allow dynamic outputs", async () => {
+  const mock = fetchMock
+    .sandbox()
+    .getOnce("https://api.github.com/repos/actions/cache/contents/action.yml?ref=v3", actionMetadata);
+
+  const workflowContext = await createWorkflowContext(workflow, "build");
+  const defaultContext = getDefaultStepsContext(workflowContext);
+
+  const stepsContext = await getStepsContext(
+    new Octokit({
+      request: {
+        fetch: mock
+      }
+    }),
+    new TTLCache(),
+    defaultContext,
+    workflowContext
+  );
+
+  // Get the step context
+  const stepContext = stepsContext?.get("cache-primes");
+  if (!stepContext) {
+    throw new Error("Expected stepContext to be defined");
+  }
+  expect(isDescriptionDictionary(stepContext)).toBe(true);
+
+  // Get the outputs - should be a dictionary, not null
+  const outputs = (stepContext as DescriptionDictionary).get("outputs");
+  if (!outputs) {
+    throw new Error("Expected outputs to be defined");
+  }
+  expect(isDescriptionDictionary(outputs)).toBe(true);
+
+  // Outputs should be marked incomplete to allow dynamic outputs
+  const outputsDict = outputs as DescriptionDictionary;
+  expect(outputsDict.complete).toBe(false);
+
+  // Known outputs from action.yml should be present
+  expect(outputsDict.get("cache-hit")).toBeDefined();
+});
+
 it("adds action outputs", async () => {
   const mock = fetchMock
     .sandbox()
@@ -83,29 +124,34 @@ it("adds action outputs", async () => {
   );
   expect(stepsContext).toBeDefined();
 
+  // Create expected outputs dict with complete = false
+  // (actions can have dynamic outputs beyond what's declared in action.yml)
+  const expectedOutputs = new DescriptionDictionary({
+    key: "cache-hit",
+    value: new data.StringData("A boolean value to indicate an exact match was found for the primary key"),
+    description: "A boolean value to indicate an exact match was found for the primary key"
+  });
+  expectedOutputs.complete = false;
+
   expect(stepsContext).toEqual(
     new DescriptionDictionary({
       key: "cache-primes",
       value: new DescriptionDictionary(
         {
           key: "outputs",
-          value: new DescriptionDictionary({
-            key: "cache-hit",
-            value: new data.StringData("A boolean value to indicate an exact match was found for the primary key"),
-            description: "A boolean value to indicate an exact match was found for the primary key"
-          })
+          value: expectedOutputs
         },
         {
           key: "conclusion",
           value: new data.Null(),
           description:
-            "The result of a completed step after `continue-on-error` is applied. Possible values are `success`, `failure`, `cancelled`, or `skipped`. When a `continue-on-error` step fails, the `outcome` is `failure`, but the final conclusion is `success`."
+            "The result of a completed step after [`continue-on-error`](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepscontinue-on-error) is applied. Possible values are `success`, `failure`, `cancelled`, or `skipped`. When a `continue-on-error` step fails, the `outcome` is `failure`, but the final conclusion is `success`."
         },
         {
           key: "outcome",
           value: new data.Null(),
           description:
-            "The result of a completed step before `continue-on-error` is applied. Possible values are `success`, `failure`, `cancelled`, or `skipped`. When a `continue-on-error` step fails, the `outcome` is `failure`, but the final conclusion is `success`."
+            "The result of a completed step before [`continue-on-error`](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepscontinue-on-error) is applied. Possible values are `success`, `failure`, `cancelled`, or `skipped`. When a `continue-on-error` step fails, the `outcome` is `failure`, but the final conclusion is `success`."
         }
       )
     })

languageserver/src/context-providers/steps.ts

@@ -3,8 +3,8 @@ import {parseActionReference} from "@actions/languageservice/action";
 import {WorkflowContext} from "@actions/languageservice/context/workflow-context";
 import {isActionStep} from "@actions/workflow-parser/model/type-guards";
 import {Octokit} from "@octokit/rest";
-import {TTLCache} from "../utils/cache";
-import {getActionOutputs} from "./action-outputs";
+import {TTLCache} from "../utils/cache.js";
+import {getActionOutputs} from "./action-outputs.js";
 
 export async function getStepsContext(
   octokit: Octokit,
@@ -58,6 +58,8 @@ export async function getStepsContext(
             continue;
           }
           const outputsDict = new DescriptionDictionary();
+          // Actions can have dynamic outputs beyond what's declared in action.yml
+          outputsDict.complete = false;
           for (const [key, value] of Object.entries(outputs)) {
             outputsDict.add(key, new data.StringData(value.description), value.description);
           }

languageserver/src/context-providers/variables.ts

@@ -2,14 +2,15 @@ import {data, DescriptionDictionary} from "@actions/expressions";
 import {Pair} from "@actions/expressions/data/expressiondata";
 import {StringData} from "@actions/expressions/data/index";
 import {WorkflowContext} from "@actions/languageservice/context/workflow-context";
-import {warn} from "@actions/languageservice/log";
+import {log, warn} from "@actions/languageservice/log";
 import {isMapping, isString} from "@actions/workflow-parser";
 import {Octokit} from "@octokit/rest";
+import {RequestError} from "@octokit/request-error";
 
-import {RepositoryContext} from "../initializationOptions";
-import {TTLCache} from "../utils/cache";
-import {errorStatus} from "../utils/error";
-import {getRepoPermission} from "../utils/repo-permission";
+import {RepositoryContext} from "../initializationOptions.js";
+import {TTLCache} from "../utils/cache.js";
+import {errorStatus} from "../utils/error.js";
+import {getRepoPermission} from "../utils/repo-permission.js";
 
 export async function getVariables(
   workflowContext: WorkflowContext,
@@ -25,6 +26,8 @@ export async function getVariables(
     return secretsContext;
   }
 
+  const variablesContext = defaultContext || new DescriptionDictionary();
+
   let environmentName: string | undefined;
   if (workflowContext?.job?.environment) {
     if (isString(workflowContext.job.environment)) {
@@ -34,58 +37,71 @@ export async function getVariables(
         if (isString(x.key) && x.key.value === "name") {
           if (isString(x.value)) {
             environmentName = x.value.value;
+          } else {
+            // this means we have a dynamic environment, in those situations we want to skip validation
+            variablesContext.complete = false;
           }
           break;
         }
       }
+    } else {
+      // if the expression is something like environment: ${{ ... }} then we want to skip validation
+      variablesContext.complete = false;
     }
   }
 
-  const variablesContext = defaultContext || new DescriptionDictionary();
-  const variables = await getRemoteVariables(octokit, cache, repo, environmentName);
+  try {
+    const variables = await getRemoteVariables(octokit, cache, repo, environmentName);
 
-  // Build combined map of variables
-  const variablesMap = new Map<
-    string,
-    {
-      key: string;
-      value: data.StringData;
-      description?: string;
-    }
-  >();
+    // Build combined map of variables
+    const variablesMap = new Map<
+      string,
+      {
+        key: string;
+        value: data.StringData;
+        description?: string;
+      }
+    >();
 
-  variables.organizationVariables.forEach(variable =>
-    variablesMap.set(variable.key.toLowerCase(), {
-      key: variable.key,
-      value: new data.StringData(variable.value.coerceString()),
-      description: `${variable.value.coerceString()} - Organization variable`
-    })
-  );
+    variables.organizationVariables.forEach(variable =>
+      variablesMap.set(variable.key.toLowerCase(), {
+        key: variable.key,
+        value: new data.StringData(variable.value.coerceString()),
+        description: `${variable.value.coerceString()} - Organization variable`
+      })
+    );
 
-  // Override org variables with repo variables
-  variables.repoVariables.forEach(variable =>
-    variablesMap.set(variable.key.toLowerCase(), {
-      key: variable.key,
-      value: new data.StringData(variable.value.coerceString()),
-      description: `${variable.value.coerceString()} - Repository variable`
-    })
-  );
+    // Override org variables with repo variables
+    variables.repoVariables.forEach(variable =>
+      variablesMap.set(variable.key.toLowerCase(), {
+        key: variable.key,
+        value: new data.StringData(variable.value.coerceString()),
+        description: `${variable.value.coerceString()} - Repository variable`
+      })
+    );
 
-  // Override repo variables with environment veriables (if defined)
-  variables.environmentVariables.forEach(variable =>
-    variablesMap.set(variable.key.toLowerCase(), {
-      key: variable.key,
-      value: new data.StringData(variable.value.coerceString()),
-      description: `${variable.value.coerceString()} - Variable for environment \`${environmentName || ""}\``
-    })
-  );
+    // Override repo variables with environment veriables (if defined)
+    variables.environmentVariables.forEach(variable =>
+      variablesMap.set(variable.key.toLowerCase(), {
+        key: variable.key,
+        value: new data.StringData(variable.value.coerceString()),
+        description: `${variable.value.coerceString()} - Variable for environment \`${environmentName || ""}\``
+      })
+    );
 
-  // Sort variables by key and add to context
-  Array.from(variablesMap.values())
-    .sort((a, b) => a.key.localeCompare(b.key))
-    .forEach(variable => variablesContext?.add(variable.key, variable.value, variable.description));
+    // Sort variables by key and add to context
+    Array.from(variablesMap.values())
+      .sort((a, b) => a.key.localeCompare(b.key))
+      .forEach(variable => variablesContext?.add(variable.key, variable.value, variable.description));
 
-  return variablesContext;
+    return variablesContext;
+  } catch (e) {
+    if (!(e instanceof RequestError)) throw e;
+    if (e.name == "HttpError" && e.status == 404) {
+      log("Failure to request variables. Ignore if you're using GitHub Enterprise Server below version 3.8");
+      return variablesContext;
+    } else throw e;
+  }
 }
 
 export async function getRemoteVariables(
@@ -106,7 +122,7 @@ export async function getRemoteVariables(
     environmentVariables:
       (environmentName &&
         (await cache.get(`${repo.owner}/${repo.name}/vars/environment/${environmentName}`, undefined, () =>
-          fetchEnvironmentVariables(octokit, repo.id, environmentName)
+          fetchEnvironmentVariables(octokit, repo.owner, repo.name, environmentName)
         ))) ||
       [],
     organizationVariables: await cache.get(`${repo.owner}/vars`, undefined, () =>
@@ -137,14 +153,16 @@ async function fetchVariables(octokit: Octokit, owner: string, name: string): Pr
 
 async function fetchEnvironmentVariables(
   octokit: Octokit,
-  repositoryId: number,
+  owner: string,
+  name: string,
   environmentName: string
 ): Promise<Pair[]> {
   try {
     return await octokit.paginate(
       octokit.actions.listEnvironmentVariables,
       {
-        repository_id: repositoryId,
+        owner: owner,
+        repo: name,
         environment_name: environmentName,
         per_page: 100
       },

languageserver/src/description-provider.ts

@@ -1,8 +1,8 @@
 import {DescriptionProvider} from "@actions/languageservice/hover";
 import {Octokit} from "@octokit/rest";
-import {getActionDescription} from "./description-providers/action-description";
-import {getActionInputDescription} from "./description-providers/action-input";
-import {TTLCache} from "./utils/cache";
+import {getActionDescription} from "./description-providers/action-description.js";
+import {getActionInputDescription} from "./description-providers/action-input.js";
+import {TTLCache} from "./utils/cache.js";
 
 export function descriptionProvider(client: Octokit | undefined, cache: TTLCache): DescriptionProvider {
   const getDescription: DescriptionProvider["getDescription"] = async (context, token, path) => {

languageserver/src/description-providers/action-description.test.ts

@@ -1,9 +1,9 @@
 import {Octokit} from "@octokit/rest";
 import fetchMock from "fetch-mock";
-import {createWorkflowContext} from "../test-utils/workflow-context";
-import {TTLCache} from "../utils/cache";
-import {getActionDescription} from "./action-description";
-import {actionsCheckoutMetadata} from "../test-utils/action-metadata";
+import {createWorkflowContext} from "../test-utils/workflow-context.js";
+import {TTLCache} from "../utils/cache.js";
+import {getActionDescription} from "./action-description.js";
+import {actionsCheckoutMetadata} from "../test-utils/action-metadata.js";
 
 const workflow = `
 name: Hello World

languageserver/src/description-providers/action-description.ts

@@ -2,8 +2,8 @@ import {actionUrl, parseActionReference} from "@actions/languageservice/action";
 import {isActionStep} from "@actions/workflow-parser/model/type-guards";
 import {Step} from "@actions/workflow-parser/model/workflow-template";
 import {Octokit} from "@octokit/rest";
-import {fetchActionMetadata} from "../utils/action-metadata";
-import {TTLCache} from "../utils/cache";
+import {fetchActionMetadata} from "../utils/action-metadata.js";
+import {TTLCache} from "../utils/cache.js";
 
 export async function getActionDescription(client: Octokit, cache: TTLCache, step: Step): Promise<string | undefined> {
   if (!isActionStep(step)) {

languageserver/src/description-providers/action-input.test.ts

@@ -2,10 +2,10 @@ import {StringToken} from "@actions/workflow-parser/templates/tokens/string-toke
 import {Octokit} from "@octokit/rest";
 import fetchMock from "fetch-mock";
 
-import {actionsCheckoutMetadata} from "../test-utils/action-metadata";
-import {createWorkflowContext} from "../test-utils/workflow-context";
-import {TTLCache} from "../utils/cache";
-import {getActionInputDescription} from "./action-input";
+import {actionsCheckoutMetadata} from "../test-utils/action-metadata.js";
+import {createWorkflowContext} from "../test-utils/workflow-context.js";
+import {TTLCache} from "../utils/cache.js";
+import {getActionInputDescription} from "./action-input.js";
 
 const workflow = `
 name: Hello World

languageserver/src/description-providers/action-input.ts

@@ -4,8 +4,8 @@ import {isActionStep} from "@actions/workflow-parser/model/type-guards";
 import {Step} from "@actions/workflow-parser/model/workflow-template";
 import {TemplateToken} from "@actions/workflow-parser/templates/tokens/template-token";
 import {Octokit} from "@octokit/rest";
-import {fetchActionMetadata} from "../utils/action-metadata";
-import {TTLCache} from "../utils/cache";
+import {fetchActionMetadata} from "../utils/action-metadata.js";
+import {TTLCache} from "../utils/cache.js";
 
 export async function getActionInputDescription(
   client: Octokit,

languageserver/src/file-provider.ts

@@ -2,8 +2,8 @@ import {File} from "@actions/workflow-parser/workflows/file";
 import {FileProvider} from "@actions/workflow-parser/workflows/file-provider";
 import {fileIdentifier} from "@actions/workflow-parser/workflows/file-reference";
 import {Octokit} from "@octokit/rest";
-import path from "path";
-import {TTLCache} from "./utils/cache";
+import {TTLCache} from "./utils/cache.js";
+import * as vscodeURI from "vscode-uri";
 
 export function getFileProvider(
   client: Octokit | undefined,
@@ -31,7 +31,10 @@ export function getFileProvider(
         throw new Error("Local file references are not supported with this configuration");
       }
 
-      const file = await readFile(path.join(workspace, ref.path));
+      const workspaceURI = vscodeURI.URI.parse(workspace);
+      const refURI = vscodeURI.Utils.joinPath(workspaceURI, ref.path);
+      const file = await readFile(refURI.toString());
+
       if (!file) {
         throw new Error(`File not found: ${ref.path}`);
       }

languageserver/src/index.ts

@@ -6,7 +6,7 @@ import {
 } from "vscode-languageserver/browser";
 import {createConnection as createNodeConnection} from "vscode-languageserver/node";
 
-import {initConnection} from "./connection";
+import {initConnection} from "./connection.js";
 
 /** Helper function determining whether we are executing with node runtime */
 function isNode(): boolean {

languageserver/src/initializationOptions.ts

@@ -1,3 +1,4 @@
+import {ExperimentalFeatures} from "@actions/expressions";
 import {LogLevel} from "@actions/languageservice/log";
 export {LogLevel} from "@actions/languageservice/log";
 
@@ -23,6 +24,17 @@ export interface InitializationOptions {
    * Desired log level
    */
   logLevel?: LogLevel;
+
+  /**
+   * If a GitHub Enterprise Server should be used, the URL of the API endpoint, eg "https://ghe.my-company.com/api/v3"
+   */
+  gitHubApiUrl?: string;
+
+  /**
+   * Experimental features that are opt-in.
+   * Features listed here may change or be removed without notice.
+   */
+  experimentalFeatures?: ExperimentalFeatures;
 }
 
 export interface RepositoryContext {

languageserver/src/on-completion.ts

@@ -2,12 +2,12 @@ import {complete} from "@actions/languageservice/complete";
 import {Octokit} from "@octokit/rest";
 import {CompletionItem, Connection, Position} from "vscode-languageserver";
 import {TextDocument} from "vscode-languageserver-textdocument";
-import {contextProviders} from "./context-providers";
-import {getFileProvider} from "./file-provider";
-import {RepositoryContext} from "./initializationOptions";
-import {Requests} from "./request";
-import {TTLCache} from "./utils/cache";
-import {valueProviders} from "./value-providers";
+import {contextProviders} from "./context-providers.js";
+import {getFileProvider} from "./file-provider.js";
+import {RepositoryContext} from "./initializationOptions.js";
+import {Requests} from "./request.js";
+import {TTLCache} from "./utils/cache.js";
+import {valueProviders} from "./value-providers.js";
 
 export async function onCompletion(
   connection: Connection,

languageserver/src/utils/action-metadata.test.ts

@@ -1,7 +1,7 @@
 import {Octokit} from "@octokit/rest";
 import fetchMock from "fetch-mock";
-import {fetchActionMetadata} from "./action-metadata";
-import {TTLCache} from "./cache";
+import {fetchActionMetadata} from "./action-metadata.js";
+import {TTLCache} from "./cache.js";
 
 // A simplified version of the action.yml file from actions/checkout
 const actionMetadataContent = `

languageserver/src/utils/action-metadata.ts

@@ -3,8 +3,8 @@ import {ActionsMetadataProvider} from "@actions/languageservice";
 import {error} from "@actions/languageservice/log";
 import {Octokit, RestEndpointMethodTypes} from "@octokit/rest";
 import {parse} from "yaml";
-import {TTLCache} from "./cache";
-import {errorMessage, errorStatus} from "./error";
+import {TTLCache} from "./cache.js";
+import {errorMessage, errorStatus} from "./error.js";
 
 export function getActionsMetadataProvider(
   client: Octokit | undefined,

languageserver/src/utils/repo-permission.ts

@@ -1,9 +1,9 @@
 import {error} from "@actions/languageservice/log";
 import {Octokit} from "@octokit/rest";
-import {RepositoryContext} from "../initializationOptions";
-import {TTLCache} from "./cache";
-import {errorStatus} from "./error";
-import {getUsername} from "./username";
+import {RepositoryContext} from "../initializationOptions.js";
+import {TTLCache} from "./cache.js";
+import {errorStatus} from "./error.js";
+import {getUsername} from "./username.js";
 
 export type RepoPermission = "admin" | "write" | "read" | "none";
 

languageserver/src/utils/username.ts

@@ -1,5 +1,5 @@
 import {Octokit} from "@octokit/rest";
-import {TTLCache} from "./cache";
+import {TTLCache} from "./cache.js";
 
 export async function getUsername(octokit: Octokit, cache: TTLCache): Promise<string> {
   return await cache.get(`/username`, undefined, () => fetchUsername(octokit));

languageserver/src/value-providers.ts

@@ -2,11 +2,11 @@ import {ValueProviderConfig} from "@actions/languageservice";
 import {WorkflowContext} from "@actions/languageservice/context/workflow-context";
 import {ValueProviderKind} from "@actions/languageservice/value-providers/config";
 import {Octokit} from "@octokit/rest";
-import {RepositoryContext} from "./initializationOptions";
-import {TTLCache} from "./utils/cache";
-import {getActionInputValues} from "./value-providers/action-inputs";
-import {getEnvironments} from "./value-providers/job-environment";
-import {getRunnerLabels} from "./value-providers/runs-on";
+import {RepositoryContext} from "./initializationOptions.js";
+import {TTLCache} from "./utils/cache.js";
+import {getActionInputValues} from "./value-providers/action-inputs.js";
+import {getEnvironments} from "./value-providers/job-environment.js";
+import {getRunnerLabels} from "./value-providers/runs-on.js";
 
 export function valueProviders(
   client: Octokit | undefined,

languageserver/src/value-providers/action-inputs.ts

@@ -3,8 +3,8 @@ import {WorkflowContext} from "@actions/languageservice/context/workflow-context
 import {Value} from "@actions/languageservice/value-providers/config";
 import {isActionStep} from "@actions/workflow-parser/model/type-guards";
 import {Octokit} from "@octokit/rest";
-import {fetchActionMetadata} from "../utils/action-metadata";
-import {TTLCache} from "../utils/cache";
+import {fetchActionMetadata} from "../utils/action-metadata.js";
+import {TTLCache} from "../utils/cache.js";
 
 export async function getActionInputs(
   client: Octokit,

languageserver/src/value-providers/job-environment.ts

@@ -1,6 +1,6 @@
 import {Value} from "@actions/languageservice/value-providers/config";
 import {Octokit} from "@octokit/rest";
-import {TTLCache} from "../utils/cache";
+import {TTLCache} from "../utils/cache.js";
 
 export async function getEnvironments(client: Octokit, cache: TTLCache, owner: string, name: string): Promise<Value[]> {
   const environments = await cache.get(`${owner}/${name}/environments`, undefined, () =>

languageserver/src/value-providers/runs-on.ts

@@ -2,8 +2,8 @@ import {log} from "@actions/languageservice/log";
 import {Value} from "@actions/languageservice/value-providers/config";
 import {DEFAULT_RUNNER_LABELS} from "@actions/languageservice/value-providers/default";
 import {Octokit} from "@octokit/rest";
-import {TTLCache} from "../utils/cache";
-import {errorMessage} from "../utils/error";
+import {TTLCache} from "../utils/cache.js";
+import {errorMessage} from "../utils/error.js";
 
 // Limitation: getRunnerLabels returns default hosted labels and labels for repository self-hosted runners.
 // It doesn't return labels for organization runners visible to the repository.

languageserver/tsconfig.build.json

@@ -5,6 +5,7 @@
     "declaration": true,
     "declarationMap": true,
     "noEmit": false,
-    "outDir": "./dist"
+    "outDir": "./dist",
+    "skipLibCheck": true
   }
 }

languageservice/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@actions/languageservice",
-  "version": "0.3.3",
+  "version": "0.3.35",
   "description": "Language service for GitHub Actions",
   "license": "MIT",
   "type": "module",
@@ -35,24 +35,27 @@
     "clean": "rimraf dist",
     "format": "prettier --write '**/*.ts'",
     "format-check": "prettier --check '**/*.ts'",
-    "lint": "eslint 'src/**/*.ts'",
+    "lint": "eslint --max-warnings 0 'src/**/*.ts'",
     "lint-fix": "eslint --fix 'src/**/*.ts'",
+    "minify-json": "node ../script/minify-json.js src/context-providers/descriptions.json src/context-providers/events/webhooks.json src/context-providers/events/objects.json src/context-providers/events/schedule.json src/context-providers/events/workflow_call.json",
+    "prebuild": "npm run minify-json",
     "prepublishOnly": "npm run build && npm run test",
+    "pretest": "npm run minify-json",
     "test": "NODE_OPTIONS=\"--experimental-vm-modules\" jest",
     "test-watch": "NODE_OPTIONS=\"--experimental-vm-modules\" jest --watch",
-    "update-webhooks": "ts-node-esm script/webhooks/index.ts",
+    "update-webhooks": "npx tsx script/webhooks/index.ts",
     "watch": "tsc --build tsconfig.build.json --watch"
   },
   "dependencies": {
-    "@actions/expressions": "^0.3.3",
-    "@actions/workflow-parser": "^0.3.3",
+    "@actions/expressions": "^0.3.35",
+    "@actions/workflow-parser": "^0.3.35",
     "vscode-languageserver-textdocument": "^1.0.7",
     "vscode-languageserver-types": "^3.17.2",
-    "vscode-uri": "^3.0.7",
+    "vscode-uri": "^3.0.8",
     "yaml": "^2.1.1"
   },
   "engines": {
-    "node": ">= 16.15"
+    "node": ">= 18"
   },
   "files": [
     "dist/**/*"

languageservice/script/webhooks/index.ts

@@ -1,12 +1,191 @@
 import {promises as fs} from "fs";
 import Webhook from "./webhook.js";
 
-import schemaImport from "rest-api-description/descriptions/api.github.com/dereferenced/api.github.com.deref.json" assert {type: "json"};
+import schemaImport from "rest-api-description/descriptions/api.github.com/dereferenced/api.github.com.deref.json";
 import {deduplicateWebhooks} from "./deduplicate.js";
 const schema = schemaImport as any;
 
 const OUTPUT_PATH = "./src/context-providers/events/webhooks.json";
 const OBJECTS_PATH = "./src/context-providers/events/objects.json";
+const ALL_OUTPUT_PATH = "./src/context-providers/events/webhooks.all.json";
+const ALL_OBJECTS_PATH = "./src/context-providers/events/objects.all.json";
+const DROP_OUTPUT_PATH = "./src/context-providers/events/webhooks.drop.json";
+const DROP_OBJECTS_PATH = "./src/context-providers/events/objects.drop.json";
+const STRIP_OUTPUT_PATH = "./src/context-providers/events/webhooks.strip.json";
+const STRIP_OBJECTS_PATH = "./src/context-providers/events/objects.strip.json";
+
+// Parse --all flag
+const generateAll = process.argv.includes("--all");
+
+// Events to drop - not valid workflow triggers (GitHub App or API-only events)
+// See: https://docs.github.com/en/actions/writing-workflows/choosing-when-your-workflow-runs/events-that-trigger-workflows
+const DROPPED_EVENTS = new Set([
+  "branch_protection_configuration",
+  "code_scanning_alert",
+  "commit_comment",
+  "custom_property",
+  "custom_property_values",
+  "dependabot_alert",
+  "deploy_key",
+  "github_app_authorization",
+  "installation",
+  "installation_repositories",
+  "installation_target",
+  "marketplace_purchase",
+  "member",
+  "membership",
+  "merge_group",
+  "meta",
+  "org_block",
+  "organization",
+  "package",
+  "personal_access_token_request",
+  "ping",
+  "repository",
+  "repository_advisory",
+  "repository_ruleset",
+  "secret_scanning_alert",
+  "secret_scanning_alert_location",
+  "security_advisory",
+  "security_and_analysis",
+  "sponsorship",
+  "star",
+  "team",
+  "team_add"
+]);
+
+// Events to keep - valid workflow triggers
+// See: https://docs.github.com/en/actions/writing-workflows/choosing-when-your-workflow-runs/events-that-trigger-workflows
+const KEPT_EVENTS = new Set([
+  "branch_protection_rule",
+  "check_run",
+  "check_suite",
+  "create",
+  "delete",
+  "deployment",
+  "deployment_status",
+  "discussion",
+  "discussion_comment",
+  "fork",
+  "gollum",
+  "issue_comment",
+  "issues",
+  "label",
+  "milestone",
+  "page_build",
+  "project",
+  "project_card",
+  "project_column",
+  "projects_v2",
+  "projects_v2_item",
+  "public",
+  "pull_request",
+  "pull_request_review",
+  "pull_request_review_comment",
+  "pull_request_review_thread",
+  "push",
+  "registry_package",
+  "release",
+  "repository_dispatch",
+  "repository_import",
+  "repository_vulnerability_alert",
+  "status",
+  "watch",
+  "workflow_dispatch",
+  "workflow_job",
+  "workflow_run"
+]);
+
+/**
+ * Fields to strip from the JSON data.
+ *
+ * EVENT_ACTION_FIELDS: stripped from each event action object (top level only)
+ * Example event action object before stripping:
+ *   {
+ *     "description": "This event is triggered when...",  // <-- stripped
+ *     "summary": "A brief summary",                      // <-- stripped
+ *     "availability": ["repository"],                    // <-- stripped
+ *     "category": "issues",                              // <-- stripped
+ *     "action": "opened",                                // kept
+ *     "bodyParameters": [...]                            // kept
+ *   }
+ *
+ * BODY_PARAM_FIELDS: stripped from every bodyParameters object, recursively through childParamsGroups
+ * Example bodyParameter object before stripping:
+ *   {
+ *     "type": "object",                                  // <-- stripped
+ *     "name": "changes",                                 // kept (used for property names)
+ *     "in": "body",                                      // <-- stripped
+ *     "description": "The changes that were made.",      // kept (used for hover docs)
+ *     "isRequired": true,                                // <-- stripped
+ *     "enum": ["a", "b"],                                // <-- stripped
+ *     "default": "a",                                    // <-- stripped
+ *     "childParamsGroups": [                             // kept (used for nested properties)
+ *       {
+ *         "type": "string",                              // <-- stripped (recursive)
+ *         "name": "from",                                // kept
+ *         "isRequired": true                             // <-- stripped (recursive)
+ *       }
+ *     ]
+ *   }
+ */
+const EVENT_ACTION_FIELDS = ["description", "summary", "availability", "category"];
+const BODY_PARAM_FIELDS = ["type", "in", "isRequired", "enum", "default"];
+
+/**
+ * Strip fields from a bodyParameter object and recursively from childParamsGroups.
+ */
+function stripBodyParam(param: any): any {
+  if (typeof param !== "object" || param === null) {
+    return param;
+  }
+
+  const result: any = {};
+  for (const [key, value] of Object.entries(param)) {
+    if (BODY_PARAM_FIELDS.includes(key)) {
+      continue; // Strip this field
+    }
+    if (key === "childParamsGroups" && Array.isArray(value)) {
+      result[key] = value.map(stripBodyParam);
+    } else {
+      result[key] = value;
+    }
+  }
+  return result;
+}
+
+/**
+ * Strip unused fields from event action data.
+ */
+function stripEventActionFields(action: any): any {
+  const result: any = {};
+  for (const [key, value] of Object.entries(action)) {
+    if (EVENT_ACTION_FIELDS.includes(key)) {
+      continue; // Strip this field
+    }
+    if (key === "bodyParameters" && Array.isArray(value)) {
+      result[key] = value.map((p: any) => (typeof p === "number" ? p : stripBodyParam(p)));
+    } else {
+      result[key] = value;
+    }
+  }
+  return result;
+}
+
+/**
+ * Strip unused fields from all webhooks.
+ * Structure: { eventName: { actionName: { ...fields } } }
+ */
+function stripFields(webhooks: Record<string, Record<string, any>>): Record<string, Record<string, any>> {
+  const result: Record<string, Record<string, any>> = {};
+  for (const [eventName, actions] of Object.entries(webhooks)) {
+    result[eventName] = {};
+    for (const [actionName, actionData] of Object.entries(actions)) {
+      result[eventName][actionName] = stripEventActionFields(actionData);
+    }
+  }
+  return result;
+}
 
 const rawWebhooks = Object.values(schema.webhooks || schema["x-webhooks"]) as any[];
 if (!rawWebhooks) {
@@ -20,11 +199,51 @@ for (const webhook of Object.values(rawWebhooks)) {
 
 await Promise.all(webhooks.map(webhook => webhook.process()));
 
+// Check for unknown events (not in DROPPED_EVENTS or KEPT_EVENTS)
+const unknownEvents: string[] = [];
+for (const webhook of webhooks) {
+  if (!DROPPED_EVENTS.has(webhook.category) && !KEPT_EVENTS.has(webhook.category)) {
+    if (!unknownEvents.includes(webhook.category)) {
+      unknownEvents.push(webhook.category);
+    }
+  }
+}
+
+if (unknownEvents.length > 0) {
+  console.error("");
+  console.error("══════════════════════════════════════════════════════════════════");
+  console.error("ERROR: New webhook event(s) detected!");
+  console.error("══════════════════════════════════════════════════════════════════");
+  console.error("");
+  console.error("The following events are not categorized:");
+  for (const event of unknownEvents.sort()) {
+    console.error(`  - ${event}`);
+  }
+  console.error("");
+  console.error("Action required:");
+  console.error("  1. Check if the event is a valid workflow trigger:");
+  console.error(
+    "     https://docs.github.com/en/actions/writing-workflows/choosing-when-your-workflow-runs/events-that-trigger-workflows"
+  );
+  console.error("");
+  console.error("  2. Add the event to DROPPED_EVENTS or KEPT_EVENTS in:");
+  console.error("     languageservice/script/webhooks/index.ts");
+  console.error("");
+  console.error("  3. See docs/json-data-files.md for more details.");
+  console.error("");
+  process.exit(1);
+}
+
 // The category is the name of the webhook
 const categorizedWebhooks: Record<string, Record<string, Webhook>> = {};
 for (const webhook of webhooks) {
   if (!webhook.action) webhook.action = "default";
 
+  // Drop unused events
+  if (DROPPED_EVENTS.has(webhook.category)) {
+    continue;
+  }
+
   if (categorizedWebhooks[webhook.category]) {
     categorizedWebhooks[webhook.category][webhook.action] = webhook;
   } else {
@@ -33,7 +252,59 @@ for (const webhook of webhooks) {
   }
 }
 
-const objectsArray = deduplicateWebhooks(categorizedWebhooks);
+// Strip fields before deduplication
+const strippedWebhooks = stripFields(categorizedWebhooks);
 
+// Deduplicate after dropping and stripping
+const objectsArray = deduplicateWebhooks(strippedWebhooks);
+
+// Write optimized output
 await fs.writeFile(OBJECTS_PATH, JSON.stringify(objectsArray, null, 2));
-await fs.writeFile(OUTPUT_PATH, JSON.stringify(categorizedWebhooks, null, 2));
+await fs.writeFile(OUTPUT_PATH, JSON.stringify(strippedWebhooks, null, 2));
+
+console.log(`Wrote ${OUTPUT_PATH} (${Object.keys(strippedWebhooks).length} events)`);
+console.log(`Wrote ${OBJECTS_PATH} (${objectsArray.length} objects)`);
+
+// Optionally generate intermediate versions for size comparison
+if (generateAll) {
+  // Helper to deep clone
+  function clone<T>(obj: T): T {
+    return JSON.parse(JSON.stringify(obj));
+  }
+
+  // Build full webhooks (no drop, no strip) from fresh data
+  const fullWebhooks: Record<string, Record<string, any>> = {};
+  for (const webhook of webhooks) {
+    const w = clone(webhook);
+    if (!w.action) w.action = "default";
+    fullWebhooks[w.category] ||= {};
+    fullWebhooks[w.category][w.action] = w;
+  }
+
+  // Generate all version (no drop, no strip)
+  const allWebhooks = clone(fullWebhooks);
+  const allObjects = deduplicateWebhooks(allWebhooks);
+  await fs.writeFile(ALL_OUTPUT_PATH, JSON.stringify(allWebhooks, null, 2));
+  await fs.writeFile(ALL_OBJECTS_PATH, JSON.stringify(allObjects, null, 2));
+  console.log(`Wrote ${ALL_OUTPUT_PATH} (${Object.keys(allWebhooks).length} events)`);
+  console.log(`Wrote ${ALL_OBJECTS_PATH} (${allObjects.length} objects)`);
+
+  // Generate drop-only version (drop events, no strip)
+  const dropWebhooks = clone(fullWebhooks);
+  for (const event of DROPPED_EVENTS) {
+    delete dropWebhooks[event];
+  }
+  const dropObjects = deduplicateWebhooks(dropWebhooks);
+  await fs.writeFile(DROP_OUTPUT_PATH, JSON.stringify(dropWebhooks, null, 2));
+  await fs.writeFile(DROP_OBJECTS_PATH, JSON.stringify(dropObjects, null, 2));
+  console.log(`Wrote ${DROP_OUTPUT_PATH} (${Object.keys(dropWebhooks).length} events)`);
+  console.log(`Wrote ${DROP_OBJECTS_PATH} (${dropObjects.length} objects)`);
+
+  // Generate strip-only version (strip fields, no drop)
+  const stripWebhooks = stripFields(clone(fullWebhooks));
+  const stripObjects = deduplicateWebhooks(stripWebhooks);
+  await fs.writeFile(STRIP_OUTPUT_PATH, JSON.stringify(stripWebhooks, null, 2));
+  await fs.writeFile(STRIP_OBJECTS_PATH, JSON.stringify(stripObjects, null, 2));
+  console.log(`Wrote ${STRIP_OUTPUT_PATH} (${Object.keys(stripWebhooks).length} events)`);
+  console.log(`Wrote ${STRIP_OBJECTS_PATH} (${stripObjects.length} objects)`);
+}

languageservice/src/action.test.ts

@@ -1,4 +1,4 @@
-import {actionIdentifier, parseActionReference as parse} from "./action";
+import {actionIdentifier, parseActionReference as parse} from "./action.js";
 
 describe("parseActionReference", () => {
   it("basic action", () => {

languageservice/src/complete-action.test.ts

@@ -0,0 +1,557 @@
+import {FeatureFlags} from "@actions/expressions";
+import {TextDocument} from "vscode-languageserver-textdocument";
+import {complete, CompletionConfig} from "./complete";
+import {clearCache} from "./utils/workflow-cache";
+
+beforeEach(() => {
+  clearCache();
+});
+
+// Config to enable action scaffolding snippets
+const scaffoldingConfig: CompletionConfig = {
+  featureFlags: new FeatureFlags({actionScaffoldingSnippets: true})
+};
+
+describe("complete action files", () => {
+  function createActionDocument(
+    content: string,
+    uri = "file:///test/action.yml"
+  ): [TextDocument, {line: number; character: number}] {
+    // Parse cursor position and remove the | character
+    const cursorIndex = content.indexOf("|");
+    if (cursorIndex === -1) {
+      throw new Error("No cursor (|) found in content");
+    }
+    const newContent = content.substring(0, cursorIndex) + content.substring(cursorIndex + 1);
+    const doc = TextDocument.create(uri, "yaml", 1, newContent);
+    const position = doc.positionAt(cursorIndex);
+    return [doc, position];
+  }
+
+  describe("expression completion in composite actions", () => {
+    it("completes inputs context", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+description: Test action
+inputs:
+  name:
+    description: The name
+  greeting:
+    description: The greeting
+    default: Hello
+runs:
+  using: composite
+  steps:
+    - run: echo "\${{ inputs.| }}"
+      shell: bash`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("name");
+      expect(labels).toContain("greeting");
+    });
+
+    it("completes steps context with prior step IDs", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+description: Test action
+runs:
+  using: composite
+  steps:
+    - id: step1
+      run: echo "hello"
+      shell: bash
+    - id: step2
+      run: echo "\${{ steps.| }}"
+      shell: bash`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("step1");
+      expect(labels).not.toContain("step2"); // Current step should not be included
+    });
+
+    it("completes step properties", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+description: Test action
+runs:
+  using: composite
+  steps:
+    - id: greet
+      run: echo "hello"
+      shell: bash
+    - run: echo "\${{ steps.greet.| }}"
+      shell: bash`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("outputs");
+      expect(labels).toContain("outcome");
+      expect(labels).toContain("conclusion");
+    });
+
+    it("does not include steps from after cursor position", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+description: Test action
+runs:
+  using: composite
+  steps:
+    - id: first
+      run: echo "first"
+      shell: bash
+    - run: echo "\${{ steps.| }}"
+      shell: bash
+    - id: last
+      run: echo "last"
+      shell: bash`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("first");
+      expect(labels).not.toContain("last");
+    });
+
+    it("completes github context in actions", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+description: Test action
+runs:
+  using: composite
+  steps:
+    - run: echo "\${{ github.| }}"
+      shell: bash`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("actor");
+      expect(labels).toContain("repository");
+      expect(labels).toContain("ref");
+    });
+
+    it("completes runner context in actions", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+description: Test action
+runs:
+  using: composite
+  steps:
+    - run: echo "\${{ runner.| }}"
+      shell: bash`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("os");
+      expect(labels).toContain("arch");
+      expect(labels).toContain("temp");
+    });
+  });
+
+  describe("top-level completions", () => {
+    it("completes top-level keys", async () => {
+      const [doc, position] = createActionDocument(`n|`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("name");
+    });
+
+    it("completes at empty line", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+|`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("description");
+      expect(labels).toContain("runs");
+      expect(labels).toContain("inputs");
+      expect(labels).toContain("outputs");
+      expect(labels).toContain("branding");
+      expect(labels).toContain("author");
+    });
+  });
+
+  describe("runs completions", () => {
+    it("completes runs.using values", async () => {
+      const [doc, position] = createActionDocument(`name: Test
+description: Test
+runs:
+  using: |`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("composite");
+      expect(labels).toContain("node20");
+      expect(labels).toContain("docker");
+    });
+
+    it("completes runs keys", async () => {
+      const [doc, position] = createActionDocument(`name: Test
+description: Test
+runs:
+  |`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("using");
+    });
+
+    it("filters runs keys for node20 actions", async () => {
+      const [doc, position] = createActionDocument(`name: Test
+description: Test
+runs:
+  using: node20
+  |`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      // Should show Node.js action keys
+      expect(labels).toContain("main");
+      expect(labels).toContain("pre");
+      expect(labels).toContain("post");
+      expect(labels).toContain("pre-if");
+      expect(labels).toContain("post-if");
+
+      // Should NOT show composite or docker keys
+      expect(labels).not.toContain("steps");
+      expect(labels).not.toContain("image");
+      expect(labels).not.toContain("entrypoint");
+    });
+
+    it("filters runs keys for composite actions", async () => {
+      const [doc, position] = createActionDocument(`name: Test
+description: Test
+runs:
+  using: composite
+  |`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      // Should show composite action keys
+      expect(labels).toContain("steps");
+
+      // Should NOT show Node.js or docker keys
+      expect(labels).not.toContain("main");
+      expect(labels).not.toContain("pre");
+      expect(labels).not.toContain("post");
+      expect(labels).not.toContain("image");
+    });
+
+    it("filters runs keys for docker actions", async () => {
+      const [doc, position] = createActionDocument(`name: Test
+description: Test
+runs:
+  using: docker
+  |`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      // Should show Docker action keys
+      expect(labels).toContain("image");
+      expect(labels).toContain("args");
+      expect(labels).toContain("env");
+      expect(labels).toContain("entrypoint");
+      expect(labels).toContain("pre-entrypoint");
+      expect(labels).toContain("post-entrypoint");
+
+      // Should NOT show Node.js or composite keys
+      expect(labels).not.toContain("main");
+      expect(labels).not.toContain("steps");
+    });
+
+    it("prioritizes using when not set", async () => {
+      const [doc, position] = createActionDocument(`name: Test
+description: Test
+runs:
+  |`);
+      const completions = await complete(doc, position);
+
+      // Find the using completion
+      const usingCompletion = completions.find(c => c.label === "using");
+      expect(usingCompletion).toBeDefined();
+
+      // It should have a sortText that makes it sort first
+      expect(usingCompletion?.sortText).toBe("0_using");
+    });
+
+    it("completes step keys inside composite action steps", async () => {
+      const [doc, position] = createActionDocument(`name: Test
+description: Test
+runs:
+  using: composite
+  steps:
+    - run: echo hello
+      shell: bash
+    - |`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      // Should show step keys, not filtered by runs-level logic
+      expect(labels).toContain("run");
+      expect(labels).toContain("uses");
+      expect(labels).toContain("shell");
+      expect(labels).toContain("id");
+      expect(labels).toContain("name");
+      expect(labels).toContain("if");
+      expect(labels).toContain("env");
+      expect(labels).toContain("working-directory");
+    });
+  });
+
+  describe("branding completions", () => {
+    it("completes branding keys", async () => {
+      const [doc, position] = createActionDocument(`name: Test
+description: Test
+runs:
+  using: node20
+  main: index.js
+branding:
+  |`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("icon");
+      expect(labels).toContain("color");
+    });
+
+    it("completes branding color values", async () => {
+      const [doc, position] = createActionDocument(`name: Test
+description: Test
+runs:
+  using: node20
+  main: index.js
+branding:
+  color: |`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("blue");
+      expect(labels).toContain("green");
+      expect(labels).toContain("red");
+    });
+  });
+
+  describe("inputs completions", () => {
+    it("completes input property keys", async () => {
+      const [doc, position] = createActionDocument(`name: Test
+description: Test
+inputs:
+  my-input:
+    |
+runs:
+  using: node20
+  main: index.js`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("description");
+      expect(labels).toContain("required");
+      expect(labels).toContain("default");
+      expect(labels).toContain("deprecationMessage");
+    });
+  });
+
+  describe("document type routing", () => {
+    it("routes action.yml to action completion", async () => {
+      const [doc, position] = createActionDocument(`n|`, "file:///my-repo/action.yml");
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("name");
+      // Should NOT contain workflow-specific keys
+      expect(labels).not.toContain("on");
+      expect(labels).not.toContain("jobs");
+    });
+
+    it("includes descriptions from schema for completion items", async () => {
+      const [doc, position] = createActionDocument(`|`, "file:///my-repo/action.yml");
+      const completions = await complete(doc, position);
+
+      const authorCompletion = completions.find(c => c.label === "author");
+      expect(authorCompletion).toBeDefined();
+      expect(authorCompletion?.documentation).toBeDefined();
+      expect((authorCompletion?.documentation as {value: string})?.value).toContain("author");
+    });
+
+    it("includes descriptions for branding completion", async () => {
+      const [doc, position] = createActionDocument(`|`, "file:///my-repo/action.yml");
+      const completions = await complete(doc, position);
+
+      const brandingCompletion = completions.find(c => c.label === "branding");
+      expect(brandingCompletion).toBeDefined();
+      expect(brandingCompletion?.documentation).toBeDefined();
+      expect((brandingCompletion?.documentation as {value: string})?.value).toContain("branding");
+    });
+
+    it("falls back to type description when property has no description", async () => {
+      // `inputs` uses shorthand form in schema: "inputs": "inputs-strict"
+      // So the property has no description, but the type `inputs-strict` does
+      const [doc, position] = createActionDocument(`|`, "file:///my-repo/action.yml");
+      const completions = await complete(doc, position);
+
+      const inputsCompletion = completions.find(c => c.label === "inputs");
+      expect(inputsCompletion).toBeDefined();
+      expect(inputsCompletion?.documentation).toBeDefined();
+      expect((inputsCompletion?.documentation as {value: string})?.value).toContain("Input parameters");
+    });
+
+    it("does not route workflow files to action completion", async () => {
+      const doc = TextDocument.create("file:///repo/.github/workflows/ci.yml", "yaml", 1, `o`);
+      const completions = await complete(doc, {line: 0, character: 1});
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("on");
+      expect(labels).toContain("jobs");
+    });
+  });
+
+  describe("action scaffolding snippets", () => {
+    it("offers full scaffolding snippets in empty file", async () => {
+      const [doc, position] = createActionDocument(`|`);
+      const completions = await complete(doc, position, scaffoldingConfig);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("Node.js Action");
+      expect(labels).toContain("Composite Action");
+      expect(labels).toContain("Docker Action");
+
+      // Verify they are snippets
+      const nodeSnippet = completions.find(c => c.label === "Node.js Action");
+      expect(nodeSnippet?.kind).toBe(15); // CompletionItemKind.Snippet
+      expect(nodeSnippet?.insertTextFormat).toBe(2); // InsertTextFormat.Snippet
+    });
+
+    it("offers full scaffolding snippets when no name or description exists", async () => {
+      const [doc, position] = createActionDocument(`author: me
+|`);
+      const completions = await complete(doc, position, scaffoldingConfig);
+
+      const nodeSnippet = completions.find(c => c.label === "Node.js Action");
+      expect(nodeSnippet).toBeDefined();
+      // Full snippet should include name:
+      expect((nodeSnippet?.textEdit as {newText: string})?.newText).toContain("name:");
+    });
+
+    it("offers runs-only snippets when name exists", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+|`);
+      const completions = await complete(doc, position, scaffoldingConfig);
+
+      const nodeSnippet = completions.find(c => c.label === "Node.js Action");
+      expect(nodeSnippet).toBeDefined();
+      // Runs-only snippet should start with inputs:, not name:
+      expect((nodeSnippet?.textEdit as {newText: string})?.newText).toMatch(/^inputs:/);
+      expect((nodeSnippet?.textEdit as {newText: string})?.newText).toContain("runs:");
+    });
+
+    it("offers runs-only snippets when description exists", async () => {
+      const [doc, position] = createActionDocument(`description: Does something
+|`);
+      const completions = await complete(doc, position, scaffoldingConfig);
+
+      const compositeSnippet = completions.find(c => c.label === "Composite Action");
+      expect(compositeSnippet).toBeDefined();
+      // Runs-only snippet should start with inputs:, not description:
+      expect((compositeSnippet?.textEdit as {newText: string})?.newText).toMatch(/^inputs:/);
+      expect((compositeSnippet?.textEdit as {newText: string})?.newText).toContain("runs:");
+    });
+
+    it("does not offer snippets when runs.using already exists", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+description: Test
+runs:
+  using: composite
+  |`);
+      const completions = await complete(doc, position, scaffoldingConfig);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).not.toContain("Node.js Action");
+      expect(labels).not.toContain("Composite Action");
+      expect(labels).not.toContain("Docker Action");
+    });
+
+    it("offers snippets inside runs when using is not set", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+description: Test
+runs:
+  |`);
+      const completions = await complete(doc, position, scaffoldingConfig);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).toContain("Node.js Action");
+      expect(labels).toContain("Composite Action");
+      expect(labels).toContain("Docker Action");
+    });
+
+    it("does not offer snippets at root level when runs exists", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+description: Test
+runs:
+  steps: []
+|`);
+      const completions = await complete(doc, position, scaffoldingConfig);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).not.toContain("Node.js Action");
+      expect(labels).not.toContain("Composite Action");
+      expect(labels).not.toContain("Docker Action");
+    });
+
+    it("does not offer snippets when nested inside runs steps", async () => {
+      const [doc, position] = createActionDocument(`name: My Action
+description: Test
+runs:
+  using: composite
+  steps:
+    - |`);
+      const completions = await complete(doc, position, scaffoldingConfig);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).not.toContain("Node.js Action");
+      expect(labels).not.toContain("Composite Action");
+      expect(labels).not.toContain("Docker Action");
+    });
+
+    it("Node.js snippet contains expected content", async () => {
+      const [doc, position] = createActionDocument(`|`);
+      const completions = await complete(doc, position, scaffoldingConfig);
+
+      const nodeSnippet = completions.find(c => c.label === "Node.js Action");
+      const text = (nodeSnippet?.textEdit as {newText: string})?.newText;
+
+      expect(text).toContain("using: node24");
+      expect(text).toContain("main:");
+      expect(text).toContain("inputs:");
+      expect(text).toContain("outputs:");
+    });
+
+    it("Composite snippet contains expected content", async () => {
+      const [doc, position] = createActionDocument(`|`);
+      const completions = await complete(doc, position, scaffoldingConfig);
+
+      const compositeSnippet = completions.find(c => c.label === "Composite Action");
+      const text = (compositeSnippet?.textEdit as {newText: string})?.newText;
+
+      expect(text).toContain("using: composite");
+      expect(text).toContain("steps:");
+      expect(text).toContain("shell: bash");
+    });
+
+    it("Docker snippet contains expected content", async () => {
+      const [doc, position] = createActionDocument(`|`);
+      const completions = await complete(doc, position, scaffoldingConfig);
+
+      const dockerSnippet = completions.find(c => c.label === "Docker Action");
+      const text = (dockerSnippet?.textEdit as {newText: string})?.newText;
+
+      expect(text).toContain("using: docker");
+      expect(text).toContain("image:");
+      expect(text).toContain("entrypoint:");
+    });
+
+    it("does not offer snippets when feature flag is disabled", async () => {
+      const [doc, position] = createActionDocument(`|`);
+      const completions = await complete(doc, position);
+      const labels = completions.map(c => c.label);
+
+      expect(labels).not.toContain("Node.js Action");
+      expect(labels).not.toContain("Composite Action");
+      expect(labels).not.toContain("Docker Action");
+    });
+  });
+});

languageservice/src/complete-action.ts

@@ -0,0 +1,468 @@
+import {TemplateToken} from "@actions/workflow-parser/templates/tokens/index";
+import {MappingToken} from "@actions/workflow-parser/templates/tokens/mapping-token";
+import {Position} from "vscode-languageserver-textdocument";
+import {CompletionItem, CompletionItemKind, InsertTextFormat, TextEdit} from "vscode-languageserver-types";
+import {Value} from "./value-providers/config.js";
+
+/**
+ * Valid keys for each action type under the `runs:` section.
+ * Source: https://github.com/actions/runner/blob/main/src/Runner.Worker/ActionManifestManager.cs
+ */
+const ACTION_NODE_KEYS = new Set(["using", "main", "pre", "post", "pre-if", "post-if"]);
+const ACTION_COMPOSITE_KEYS = new Set(["using", "steps"]);
+const ACTION_DOCKER_KEYS = new Set([
+  "using",
+  "image",
+  "args",
+  "env",
+  "entrypoint",
+  "pre-entrypoint",
+  "pre-if",
+  "post-entrypoint",
+  "post-if"
+]);
+
+/**
+ * Action scaffolding snippets.
+ *
+ * Full variants include name, description, inputs, outputs, and runs.
+ * Runs-only variants include just the runs block.
+ */
+const ACTION_SNIPPET_NODEJS_FULL = `name: '\${1:Action Name}'
+description: '\${2:What this action does}'
+
+inputs:
+  name:
+    description: 'Name to greet'
+    required: false
+    default: 'World'
+
+outputs:
+  greeting:
+    description: 'The greeting message'
+
+runs:
+  # For more on JavaScript actions (including @actions/toolkit), see:
+  # https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-javascript-action
+  using: node24
+  main: index.js
+  # Sample index.js (vanilla JS, no build required):
+  #
+  #   const fs = require('fs');
+  #   const name = process.env.INPUT_NAME || 'World';
+  #   const greeting = \\\`Hello \\\${name}\\\`;
+  #   console.log(greeting);
+  #   fs.appendFileSync(process.env.GITHUB_OUTPUT, \\\`greeting=\\\${greeting}\\\\n\\\`);
+  #
+  # For JavaScript actions with @actions/toolkit, see:
+  # https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-javascript-action
+`;
+
+const ACTION_SNIPPET_NODEJS_RUNS = `inputs:
+  name:
+    description: 'Name to greet'
+    required: false
+    default: 'World'
+
+outputs:
+  greeting:
+    description: 'The greeting message'
+
+runs:
+  # For more on JavaScript actions (including @actions/toolkit), see:
+  # https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-javascript-action
+  using: node24
+  main: index.js
+  # Sample index.js (vanilla JS, no build required):
+  #
+  #   const fs = require('fs');
+  #   const name = process.env.INPUT_NAME || 'World';
+  #   const greeting = \\\`Hello \\\${name}\\\`;
+  #   console.log(greeting);
+  #   fs.appendFileSync(process.env.GITHUB_OUTPUT, \\\`greeting=\\\${greeting}\\\\n\\\`);
+`;
+
+const ACTION_SNIPPET_NODEJS_USING = `# For more on JavaScript actions (including @actions/toolkit), see:
+  # https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-javascript-action
+  using: node24
+  main: index.js
+  # Sample index.js (vanilla JS, no build required):
+  #
+  #   console.log('Hello World');
+`;
+
+const ACTION_SNIPPET_COMPOSITE_FULL = `name: '\${1:Action Name}'
+description: '\${2:What this action does}'
+
+inputs:
+  name:
+    description: 'Name to greet'
+    required: false
+    default: 'World'
+
+outputs:
+  greeting:
+    description: 'The greeting message'
+    value: \\\${{ steps.greet.outputs.greeting }}
+
+runs:
+  # For more on composite actions, see:
+  # https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-composite-action
+  using: composite
+  steps:
+    - id: greet
+      shell: bash
+      env:
+        INPUT_NAME: \\\${{ inputs.name }}
+      run: |
+        GREETING="Hello $INPUT_NAME"
+        echo "$GREETING"
+        echo "greeting=$GREETING" >> $GITHUB_OUTPUT
+`;
+
+const ACTION_SNIPPET_COMPOSITE_RUNS = `inputs:
+  name:
+    description: 'Name to greet'
+    required: false
+    default: 'World'
+
+outputs:
+  greeting:
+    description: 'The greeting message'
+    value: \\\${{ steps.greet.outputs.greeting }}
+
+runs:
+  # For more on composite actions, see:
+  # https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-composite-action
+  using: composite
+  steps:
+    - id: greet
+      shell: bash
+      env:
+        INPUT_NAME: \\\${{ inputs.name }}
+      run: |
+        GREETING="Hello $INPUT_NAME"
+        echo "$GREETING"
+        echo "greeting=$GREETING" >> $GITHUB_OUTPUT
+`;
+
+const ACTION_SNIPPET_COMPOSITE_USING = `# For more on composite actions, see:
+  # https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-composite-action
+  using: composite
+  steps:
+    - shell: bash
+      run: echo "Hello World"
+`;
+
+const ACTION_SNIPPET_DOCKER_FULL = `name: '\${1:Action Name}'
+description: '\${2:What this action does}'
+
+inputs:
+  name:
+    description: 'Name to greet'
+    required: false
+    default: 'World'
+
+outputs:
+  greeting:
+    description: 'The greeting message'
+
+runs:
+  # For more on Docker actions, see:
+  # https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-docker-container-action
+  using: docker
+  # 'docker://image:tag' uses pre-built image, 'Dockerfile' builds locally
+  image: '\${3:docker://alpine:3.20}'
+  env:
+    INPUT_NAME: \\\${{ inputs.name }}
+  entrypoint: '\${4:sh}'
+  args:
+    - -c
+    - |
+      GREETING="Hello $INPUT_NAME"
+      echo "$GREETING"
+      echo "greeting=$GREETING" >> $GITHUB_OUTPUT
+`;
+
+const ACTION_SNIPPET_DOCKER_RUNS = `inputs:
+  name:
+    description: 'Name to greet'
+    required: false
+    default: 'World'
+
+outputs:
+  greeting:
+    description: 'The greeting message'
+
+runs:
+  # For more on Docker actions, see:
+  # https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-docker-container-action
+  using: docker
+  # 'docker://image:tag' uses pre-built image, 'Dockerfile' builds locally
+  image: '\${1:docker://alpine:3.20}'
+  env:
+    INPUT_NAME: \\\${{ inputs.name }}
+  entrypoint: '\${2:sh}'
+  args:
+    - -c
+    - |
+      GREETING="Hello $INPUT_NAME"
+      echo "$GREETING"
+      echo "greeting=$GREETING" >> $GITHUB_OUTPUT
+`;
+
+const ACTION_SNIPPET_DOCKER_USING = `# For more on Docker actions, see:
+  # https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-docker-container-action
+  using: docker
+  # 'docker://image:tag' uses pre-built image, 'Dockerfile' builds locally
+  image: '\${1:docker://alpine:3.20}'
+  entrypoint: '\${2:sh}'
+  args:
+    - -c
+    - echo "Hello World"
+`;
+
+/**
+ * Filters action.yml `runs:` completions based on the `using:` value.
+ *
+ * When the user is completing keys under `runs:`:
+ * - If `using: node20` is set, only show Node.js action keys
+ * - If `using: composite` is set, only show composite action keys
+ * - If `using: docker` is set, only show Docker action keys
+ * - If `using:` is not set, show all keys but prioritize `using` first
+ */
+export function filterActionRunsCompletions(values: Value[], path: TemplateToken[], root: TemplateToken): Value[] {
+  // Find the runs mapping from the root
+  let runsMapping: MappingToken | undefined;
+  if (root instanceof MappingToken) {
+    for (let i = 0; i < root.count; i++) {
+      const {key, value} = root.get(i);
+      if (key.toString().toLowerCase() === "runs" && value instanceof MappingToken) {
+        runsMapping = value;
+        break;
+      }
+    }
+  }
+  if (!runsMapping) {
+    return values;
+  }
+
+  // Check if the runs mapping is in our path (meaning we're completing inside it)
+  const isInsideRuns = path.some(token => token === runsMapping);
+  if (!isInsideRuns) {
+    return values;
+  }
+
+  // Find where runsMapping is in the path
+  const runsMappingIndex = path.indexOf(runsMapping);
+  if (runsMappingIndex === -1) {
+    return values;
+  }
+
+  // Check if there's anything after runsMapping in the path
+  // If so, we're nested deeper (e.g., inside steps sequence or a step mapping)
+  if (runsMappingIndex < path.length - 1) {
+    return values;
+  }
+
+  // Get the using value from the runs mapping
+  let usingValue: string | undefined;
+  for (let i = 0; i < runsMapping.count; i++) {
+    const {key, value} = runsMapping.get(i);
+    if (key.toString().toLowerCase() === "using") {
+      usingValue = value.toString();
+      break;
+    }
+  }
+
+  // Determine which keys to allow
+  let allowedKeys: Set<string>;
+
+  if (!usingValue) {
+    // No using value set - show all keys but prioritize "using"
+    return values.map(v => {
+      if (v.label.toLowerCase() === "using") {
+        return {...v, sortText: "0_using"}; // Sort first
+      }
+      return v;
+    });
+  } else if (usingValue.match(/^node\d+$/i)) {
+    allowedKeys = ACTION_NODE_KEYS;
+  } else if (usingValue.toLowerCase() === "composite") {
+    allowedKeys = ACTION_COMPOSITE_KEYS;
+  } else if (usingValue.toLowerCase() === "docker") {
+    allowedKeys = ACTION_DOCKER_KEYS;
+  } else {
+    // Unknown using value - show all
+    return values;
+  }
+
+  // Filter to only allowed keys
+  return values.filter(v => allowedKeys.has(v.label.toLowerCase()));
+}
+
+/**
+ * Gets action scaffolding snippet completions for action.yml files.
+ *
+ * Returns snippet completions when `runs.using` is not present, offering
+ * three action types: Node.js, Composite, and Docker.
+ *
+ * Three variants per type:
+ * - "_FULL": Full scaffold with name, description, inputs, outputs, and runs
+ * - "_RUNS": Inputs, outputs, and runs (when name/description already exists)
+ * - "_USING": Minimal runs content (when inside `runs:` mapping)
+ *
+ * Which variant is shown depends on context:
+ * - Inside `runs:` mapping → "_USING" variants
+ * - At root with name/description → "_RUNS" variants
+ * - At root without name/description → "_FULL" variants
+ */
+export function getActionScaffoldingSnippets(
+  root: TemplateToken | undefined,
+  path: TemplateToken[],
+  position: Position
+): CompletionItem[] {
+  // Get the runs mapping from the root, if it exists
+  let runsMapping: MappingToken | undefined;
+  if (root instanceof MappingToken) {
+    for (let i = 0; i < root.count; i++) {
+      const {key, value} = root.get(i);
+      if (key.toString().toLowerCase() === "runs" && value instanceof MappingToken) {
+        runsMapping = value;
+        break;
+      }
+    }
+  }
+
+  // Check if runs.using already exists - if so, no scaffolding needed
+  if (runsMapping) {
+    for (let i = 0; i < runsMapping.count; i++) {
+      const {key} = runsMapping.get(i);
+      if (key.toString().toLowerCase() === "using") {
+        return [];
+      }
+    }
+  }
+
+  // Show "_USING" variants directly inside `runs`
+  const runsMappingIndex = runsMapping ? path.indexOf(runsMapping) : -1;
+  const isDirectlyInsideRuns = runsMappingIndex !== -1 && runsMappingIndex === path.length - 1;
+  if (isDirectlyInsideRuns) {
+    return [
+      createSnippetCompletion(
+        "Node.js Action",
+        "Scaffold a Node.js action",
+        ACTION_SNIPPET_NODEJS_USING,
+        position,
+        "1_nodejs"
+      ),
+      createSnippetCompletion(
+        "Composite Action",
+        "Scaffold a composite action",
+        ACTION_SNIPPET_COMPOSITE_USING,
+        position,
+        "2_composite"
+      ),
+      createSnippetCompletion(
+        "Docker Action",
+        "Scaffold a Docker action",
+        ACTION_SNIPPET_DOCKER_USING,
+        position,
+        "3_docker"
+      )
+    ];
+  }
+
+  // Not at root or `runs` already exists?
+  const isAtRoot = path.length === 0 || (path.length === 1 && path[0] === root);
+  if (!isAtRoot || runsMapping) {
+    return [];
+  }
+
+  // Determine which variant to show based on existing root keys
+  let hasNameOrDescription = false;
+  if (root instanceof MappingToken) {
+    for (let i = 0; i < root.count; i++) {
+      const keyStr = root.get(i).key.toString().toLowerCase();
+      if (keyStr === "name" || keyStr === "description") {
+        hasNameOrDescription = true;
+        break;
+      }
+    }
+  }
+
+  // Show "_RUNS" variants (inputs, outputs, and runs block)
+  if (hasNameOrDescription) {
+    return [
+      createSnippetCompletion(
+        "Node.js Action",
+        "Scaffold a Node.js action",
+        ACTION_SNIPPET_NODEJS_RUNS,
+        position,
+        "1_nodejs"
+      ),
+      createSnippetCompletion(
+        "Composite Action",
+        "Scaffold a composite action",
+        ACTION_SNIPPET_COMPOSITE_RUNS,
+        position,
+        "2_composite"
+      ),
+      createSnippetCompletion(
+        "Docker Action",
+        "Scaffold a Docker action",
+        ACTION_SNIPPET_DOCKER_RUNS,
+        position,
+        "3_docker"
+      )
+    ];
+  }
+
+  // Show "_FULL" variants (complete scaffold)
+  return [
+    createSnippetCompletion(
+      "Node.js Action",
+      "Scaffold a complete Node.js action",
+      ACTION_SNIPPET_NODEJS_FULL,
+      position,
+      "1_nodejs"
+    ),
+    createSnippetCompletion(
+      "Composite Action",
+      "Scaffold a complete composite action",
+      ACTION_SNIPPET_COMPOSITE_FULL,
+      position,
+      "2_composite"
+    ),
+    createSnippetCompletion(
+      "Docker Action",
+      "Scaffold a complete Docker action",
+      ACTION_SNIPPET_DOCKER_FULL,
+      position,
+      "3_docker"
+    )
+  ];
+}
+
+/**
+ * Creates a snippet completion item.
+ */
+function createSnippetCompletion(
+  label: string,
+  description: string,
+  snippetText: string,
+  position: Position,
+  sortText: string
+): CompletionItem {
+  return {
+    label,
+    kind: CompletionItemKind.Snippet,
+    documentation: {
+      kind: "markdown",
+      value: description
+    },
+    insertTextFormat: InsertTextFormat.Snippet,
+    sortText,
+    textEdit: TextEdit.insert(position, snippetText)
+  };
+}

languageservice/src/complete.expressions.test.ts

@@ -1,13 +1,13 @@
 /* eslint-disable @typescript-eslint/no-non-null-assertion */
 import {data, DescriptionDictionary} from "@actions/expressions";
 import {CompletionItem, CompletionItemKind} from "vscode-languageserver-types";
-import {complete, getExpressionInput} from "./complete";
-import {ContextProviderConfig} from "./context-providers/config";
-import {registerLogger} from "./log";
-import {getPositionFromCursor} from "./test-utils/cursor-position";
-import {TestLogger} from "./test-utils/logger";
-import {testFileProvider} from "./test-utils/test-file-provider";
-import {clearCache} from "./utils/workflow-cache";
+import {complete, getExpressionInput} from "./complete.js";
+import {ContextProviderConfig} from "./context-providers/config.js";
+import {registerLogger} from "./log.js";
+import {getPositionFromCursor} from "./test-utils/cursor-position.js";
+import {TestLogger} from "./test-utils/logger.js";
+import {testFileProvider} from "./test-utils/test-file-provider.js";
+import {clearCache} from "./utils/workflow-cache.js";
 
 const contextProviderConfig: ContextProviderConfig = {
   getContext: (context: string) => {
@@ -100,7 +100,7 @@ describe("expressions", () => {
         label: "api_url",
         documentation: {
           kind: "markdown",
-          value: "The URL of the GitHub Actions REST API."
+          value: "The URL of the GitHub REST API."
         },
         kind: CompletionItemKind.Variable
       });
@@ -299,7 +299,16 @@ jobs:
         "on: push\njobs:\n  build:\n    runs-on: ubuntu-latest\n    environment:\n      url: ${{ runner.| }}\n    steps:\n      - run: echo";
       const result = await complete(...getPositionFromCursor(input), {contextProviderConfig});
 
-      expect(result.map(x => x.label)).toEqual(["arch", "name", "os", "temp", "tool_cache"]);
+      expect(result.map(x => x.label)).toEqual([
+        "arch",
+        "debug",
+        "environment",
+        "name",
+        "os",
+        "temp",
+        "tool_cache",
+        "workspace"
+      ]);
     });
 
     describe("job if", () => {
@@ -861,7 +870,7 @@ jobs:
   });
 
   describe("strategy context", () => {
-    it("strategy is not suggested when outside of a matrix job", async () => {
+    it("strategy is suggested even when no strategy defined", async () => {
       const input = `
 on: push
 
@@ -875,7 +884,7 @@ jobs:
 
       const result = await complete(...getPositionFromCursor(input), {contextProviderConfig});
 
-      expect(result.map(x => x.label)).not.toContain("strategy");
+      expect(result.map(x => x.label)).toContain("strategy");
     });
 
     it("strategy is suggested within a matrix job", async () => {
@@ -922,7 +931,7 @@ jobs:
   });
 
   describe("matrix context", () => {
-    it("matrix is not suggested when outside of a matrix job", async () => {
+    it("matrix is suggested even when no strategy defined", async () => {
       const input = `
 on: push
 
@@ -936,7 +945,7 @@ jobs:
 
       const result = await complete(...getPositionFromCursor(input), {contextProviderConfig});
 
-      expect(result.map(x => x.label)).not.toContain("strategy");
+      expect(result.map(x => x.label)).toContain("matrix");
     });
 
     it("matrix is suggested within a matrix job", async () => {
@@ -1101,7 +1110,7 @@ jobs:
 `;
 
       const result = await complete(...getPositionFromCursor(input), {contextProviderConfig});
-      expect(result.map(x => x.label)).toEqual(["container", "services", "status"]);
+      expect(result.map(x => x.label)).toEqual(["check_run_id", "container", "services", "status"]);
     });
 
     it("job context is suggested within a job output", async () => {
@@ -1123,10 +1132,12 @@ jobs:
         "github",
         "inputs",
         "job",
+        "matrix",
         "needs",
         "runner",
         "secrets",
         "steps",
+        "strategy",
         "vars",
         "contains",
         "endsWith",
@@ -1268,7 +1279,7 @@ jobs:
 on: push
 jobs:
   a:
-    uses: ./reusable-workflow-with-outputs.yaml
+    uses: ./.github/workflows/reusable-workflow-with-outputs.yaml
   b:
     needs: [a]
     runs-on: ubuntu-latest

languageservice/src/complete.multiline-if.test.ts

@@ -0,0 +1,169 @@
+import {complete} from "./complete.js";
+import {TextDocument} from "vscode-languageserver-textdocument";
+import {clearCache} from "./utils/workflow-cache.js";
+import {getPositionFromCursor} from "./test-utils/cursor-position.js";
+
+beforeEach(() => {
+  clearCache();
+});
+
+describe("Issue #81 - multi-line if expression completion", () => {
+  it("should complete in block scalar if with | (exact position)", async () => {
+    // Exact reproduction from issue - cursor after "github." in block scalar
+    const input = `on: push
+
+jobs:
+  build:
+    if: |
+      github.
+    runs-on: ubuntu-latest
+    steps:
+    - run: echo`;
+
+    const doc = TextDocument.create("file:///test.yaml", "yaml", 1, input);
+    // Line 5 (0-indexed) = "      github.", character 13 = after the dot
+    const pos = {line: 5, character: 13};
+
+    const result = await complete(doc, pos, {});
+
+    expect(result.length).toBeGreaterThan(0);
+    expect(result.map(x => x.label)).toContain("event");
+    expect(result.map(x => x.label)).toContain("actor");
+  });
+
+  it("should complete in block scalar if with > (exact position)", async () => {
+    const input = `on: push
+
+jobs:
+  build:
+    if: >
+      github.
+    runs-on: ubuntu-latest
+    steps:
+    - run: echo`;
+
+    const doc = TextDocument.create("file:///test.yaml", "yaml", 1, input);
+    const pos = {line: 5, character: 13};
+
+    const result = await complete(doc, pos, {});
+
+    expect(result.length).toBeGreaterThan(0);
+    expect(result.map(x => x.label)).toContain("event");
+  });
+
+  it("should complete in block scalar with multiple lines", async () => {
+    const input = `on: push
+jobs:
+  build:
+    if: |
+      github.event_name == 'push' &&
+      github.|
+    runs-on: ubuntu-latest
+    steps:
+    - run: echo`;
+
+    // Skip 1 to skip the `|` block scalar indicator (same character as cursor marker)
+    const result = await complete(...getPositionFromCursor(input, 1), {});
+
+    expect(result.length).toBeGreaterThan(0);
+    expect(result.map(x => x.label)).toContain("event");
+  });
+
+  it("should complete step if in block scalar", async () => {
+    const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - run: echo
+      if: |
+        github.
+`;
+
+    const doc = TextDocument.create("file:///test.yaml", "yaml", 1, input);
+    // Line 7 = "        github.", character 15 = after the dot (8 spaces + 7 chars)
+    const pos = {line: 7, character: 15};
+
+    const result = await complete(doc, pos, {});
+
+    expect(result.length).toBeGreaterThan(0);
+    expect(result.map(x => x.label)).toContain("event");
+  });
+
+  it("should complete in block scalar with ${{ expression markers", async () => {
+    // This case works because transform() skips lines with ${{
+    // Note: Using explicit position because | appears in multiple places (block scalar, ||, cursor)
+    const input = `on: push
+jobs:
+  build:
+    if: |
+      \${{
+        github.ref == 'refs/heads/main' ||
+        github.
+    runs-on: ubuntu-latest
+    steps:
+    - run: echo`;
+
+    const doc = TextDocument.create("file:///test.yaml", "yaml", 1, input);
+    // Line 6 = "        github." = 8 spaces + 7 chars = 15 chars, cursor after dot is at char 15
+    const pos = {line: 6, character: 15};
+
+    const result = await complete(doc, pos, {});
+
+    expect(result.length).toBeGreaterThan(0);
+    expect(result.map(x => x.label)).toContain("ref");
+    expect(result.map(x => x.label)).toContain("ref_name");
+  });
+});
+
+describe("Edge cases for getOffsetInContent", () => {
+  it("should complete in single-line if (not block scalar)", async () => {
+    const input = `on: push
+jobs:
+  build:
+    if: github.|
+    runs-on: ubuntu-latest
+    steps:
+    - run: echo`;
+
+    const result = await complete(...getPositionFromCursor(input), {});
+
+    expect(result.length).toBeGreaterThan(0);
+    expect(result.map(x => x.label)).toContain("event");
+  });
+
+  it("should complete on third content line of block scalar", async () => {
+    const input = `on: push
+jobs:
+  build:
+    if: |
+      github.event_name == 'push' &&
+      github.ref == 'refs/heads/main' &&
+      github.|
+    runs-on: ubuntu-latest
+    steps:
+    - run: echo`;
+
+    const result = await complete(...getPositionFromCursor(input, 1), {});
+
+    expect(result.length).toBeGreaterThan(0);
+    expect(result.map(x => x.label)).toContain("event");
+  });
+
+  it("should complete when block scalar has empty first line", async () => {
+    const input = `on: push
+jobs:
+  build:
+    if: |
+
+      github.|
+    runs-on: ubuntu-latest
+    steps:
+    - run: echo`;
+
+    const result = await complete(...getPositionFromCursor(input, 1), {});
+
+    expect(result.length).toBeGreaterThan(0);
+    expect(result.map(x => x.label)).toContain("event");
+  });
+});

languageservice/src/complete.reusable-workflows.test.ts

@@ -1,8 +1,8 @@
 import {CompletionItem, MarkupContent} from "vscode-languageserver-types";
-import {complete} from "./complete";
-import {getPositionFromCursor} from "./test-utils/cursor-position";
-import {testFileProvider} from "./test-utils/test-file-provider";
-import {clearCache} from "./utils/workflow-cache";
+import {complete} from "./complete.js";
+import {getPositionFromCursor} from "./test-utils/cursor-position.js";
+import {testFileProvider} from "./test-utils/test-file-provider.js";
+import {clearCache} from "./utils/workflow-cache.js";
 
 function mapResult(result: CompletionItem[]) {
   return result.map(x => {
@@ -21,7 +21,7 @@ on: push
 
 jobs:
   build:
-    uses: ./reusable-workflow-with-inputs.yaml
+    uses: ./.github/workflows/reusable-workflow-with-inputs.yaml
     with:
       |
 `;
@@ -49,7 +49,7 @@ on: push
 
 jobs:
   build:
-    uses: ./reusable-workflow-with-inputs.yaml
+    uses: ./.github/workflows/reusable-workflow-with-inputs.yaml
     with:
       username: monalisa
       |
@@ -74,7 +74,7 @@ on: push
 
 jobs:
   build:
-    uses: ./reusable-workflow-with-inputs.yaml
+    uses: ./.github/workflows/reusable-workflow-with-inputs.yaml
     secrets:
       |
 `;
@@ -102,7 +102,7 @@ on: push
 
 jobs:
   build:
-    uses: ./reusable-workflow-with-inputs.yaml
+    uses: ./.github/workflows/reusable-workflow-with-inputs.yaml
     secrets: |
 `;
     const result = await complete(...getPositionFromCursor(input), {fileProvider: testFileProvider});
@@ -117,7 +117,7 @@ on: push
 
 jobs:
   build:
-    uses: ./reusable-workflow-with-inputs.yaml
+    uses: ./.github/workflows/reusable-workflow-with-inputs.yaml
     secrets:
       envPAT: "myPAT"
       |

languageservice/src/complete.test.ts

@@ -1,11 +1,11 @@
 /* eslint-disable @typescript-eslint/no-non-null-assertion */
 import {MarkupContent, TextEdit} from "vscode-languageserver-types";
-import {complete} from "./complete";
-import {registerLogger} from "./log";
-import {getPositionFromCursor} from "./test-utils/cursor-position";
-import {TestLogger} from "./test-utils/logger";
-import {ValueProviderConfig, ValueProviderKind} from "./value-providers/config";
-import {clearCache} from "./utils/workflow-cache";
+import {complete} from "./complete.js";
+import {registerLogger} from "./log.js";
+import {getPositionFromCursor} from "./test-utils/cursor-position.js";
+import {TestLogger} from "./test-utils/logger.js";
+import {clearCache} from "./utils/workflow-cache.js";
+import {ValueProviderConfig, ValueProviderKind} from "./value-providers/config.js";
 
 registerLogger(new TestLogger());
 
@@ -19,9 +19,12 @@ describe("completion", () => {
     const result = await complete(...getPositionFromCursor(input));
 
     expect(result).not.toBeUndefined();
-    expect(result.length).toEqual(12);
+    // 12 runner labels + 2 escape hatches (switch to list, switch to full syntax)
+    expect(result.length).toEqual(14);
     const labels = result.map(x => x.label);
     expect(labels).toContain("macos-latest");
+    expect(labels).toContain("(switch to list)");
+    expect(labels).toContain("(switch to mapping)");
   });
 
   it("needs", async () => {
@@ -44,7 +47,7 @@ jobs:
     const result = await complete(...getPositionFromCursor(input));
 
     expect(result).not.toBeUndefined();
-    expect(result.length).toEqual(8);
+    expect(result.length).toEqual(13);
     expect(result[0].label).toEqual("concurrency");
   });
 
@@ -70,7 +73,7 @@ jobs:
     |`;
     const result = await complete(...getPositionFromCursor(input));
     expect(result).not.toBeUndefined();
-    expect(result.length).toEqual(20);
+    expect(result.length).toEqual(30);
   });
 
   it("string definition completion in sequence", async () => {
@@ -95,6 +98,7 @@ jobs:
   release:
     types: |`;
     const result = await complete(...getPositionFromCursor(input));
+    // Expect string values plus escape hatch to switch to list form
     expect(result.map(x => x.label)).toEqual([
       "created",
       "deleted",
@@ -102,7 +106,8 @@ jobs:
       "prereleased",
       "published",
       "released",
-      "unpublished"
+      "unpublished",
+      "(switch to list)"
     ]);
   });
 
@@ -190,8 +195,11 @@ jobs:
     const result = await complete(...getPositionFromCursor(input), {valueProviderConfig: config});
 
     expect(result).not.toBeUndefined();
-    expect(result.length).toEqual(1);
+    // Custom value plus escape hatches for list and full syntax
+    expect(result.length).toEqual(3);
     expect(result[0].label).toEqual("my-custom-label");
+    expect(result.map(x => x.label)).toContain("(switch to list)");
+    expect(result.map(x => x.label)).toContain("(switch to mapping)");
   });
 
   it("custom value providers for sequences", async () => {
@@ -212,7 +220,9 @@ jobs:
     expect(result[0].label).toEqual("my-custom-label");
   });
 
-  it("does not show parent mapping sibling keys", async () => {
+  it("does not show mapping keys or parent sibling keys in Key mode", async () => {
+    // At `container: |`, the scalar form is a string with no constants.
+    // Mapping keys should NOT be shown inline - but escape hatch to full syntax IS shown.
     const input = `on: push
 jobs:
   build:
@@ -220,20 +230,21 @@ jobs:
     runs-on: ubuntu-latest`;
     const result = await complete(...getPositionFromCursor(input));
     expect(result).not.toBeUndefined();
-    expect(result.length).toEqual(6);
-    // Should not contain other top-level job keys like `if` and `runs-on`
-    expect(result.map(x => x.label)).not.toContain("if");
-    expect(result.map(x => x.label)).not.toContain("runs-on");
+    // Only escape hatch to full syntax (container has mapping form but no sequence)
+    expect(result.map(x => x.label)).toEqual(["(switch to mapping)"]);
   });
 
-  it("shows mapping keys within a new map ", async () => {
+  it("does not show mapping keys in Key mode when structure is uncommitted", async () => {
+    // At `concurrency: |`, user is in Key mode but hasn't committed to a structure.
+    // The scalar form is a string with no constants, so no scalar completions.
+    // But escape hatch to full syntax IS shown as a way out.
     const input = `on: push
 jobs:
   build:
     concurrency: |`;
     const result = await complete(...getPositionFromCursor(input));
     expect(result).not.toBeUndefined();
-    expect(result.map(x => x.label).sort()).toEqual(["cancel-in-progress", "group"]);
+    expect(result.map(x => x.label)).toEqual(["(switch to mapping)"]);
   });
 
   it("job key", async () => {
@@ -243,7 +254,7 @@ jobs:
     runs-|`;
     const result = await complete(...getPositionFromCursor(input));
     expect(result).not.toBeUndefined();
-    expect(result).toHaveLength(20);
+    expect(result).toHaveLength(30);
   });
 
   it("job key with comment afterwards", async () => {
@@ -254,7 +265,7 @@ jobs:
   #`;
     const result = await complete(...getPositionFromCursor(input));
     expect(result).not.toBeUndefined();
-    expect(result).toHaveLength(20);
+    expect(result).toHaveLength(30);
   });
 
   it("job key with other values afterwards", async () => {
@@ -266,7 +277,10 @@ jobs:
     concurrency: 'group-name'`;
     const result = await complete(...getPositionFromCursor(input));
     expect(result).not.toBeUndefined();
-    expect(result).toHaveLength(19);
+    // Verify we get job-level completions, but concurrency is already present so excluded
+    expect(result.length).toBeGreaterThan(20);
+    expect(result.some(x => x.label === "runs-on")).toBe(true);
+    expect(result.some(x => x.label === "concurrency")).toBe(false);
   });
 
   it("step key without space after colon", async () => {
@@ -335,7 +349,9 @@ jobs:
     - uses: actions/checkout@v2
 `;
     const result = await complete(...getPositionFromCursor(input));
-    expect(result).toHaveLength(16);
+    // Verify we get job-level completions including runs-on variants
+    expect(result.length).toBeGreaterThan(20);
+    expect(result.some(x => x.label === "steps")).toBe(true);
   });
 
   it("complete from behind a colon will replace it", async () => {
@@ -348,7 +364,8 @@ jobs:
     - uses: actions/checkout@v2
 `;
     const result = await complete(...getPositionFromCursor(input));
-    expect(result).toHaveLength(16);
+    // Verify we get job-level completions
+    expect(result.length).toBeGreaterThan(20);
     const textEdit = result[0].textEdit as TextEdit;
     expect(textEdit.range).toEqual({
       start: {line: 5, character: 4},
@@ -406,7 +423,7 @@ jobs:
     expect(result.map(e => e.label)).toContain("runs-on");
 
     const textEdit = result.filter(e => e.label === "runs-on")[0].textEdit as TextEdit;
-    expect(textEdit.newText).toEqual("runs-on");
+    expect(textEdit.newText).toEqual("runs-on: ");
     expect(textEdit.range).toEqual({
       start: {line: 3, character: 4},
       end: {line: 3, character: 10}
@@ -421,7 +438,7 @@ jobs:
     expect(result.map(e => e.label)).toContain("runs-on");
 
     const textEdit = result.filter(e => e.label === "runs-on")[0].textEdit as TextEdit;
-    expect(textEdit.newText).toEqual("runs-on");
+    expect(textEdit.newText).toEqual("runs-on: ");
     expect(textEdit.range).toEqual({
       start: {line: 3, character: 4},
       end: {line: 3, character: 4}
@@ -447,8 +464,9 @@ jobs:
         "timeout-minutes: "
       ]);
 
-      // One-of
-      expect(result.filter(x => x.label === "concurrency").map(x => x.textEdit?.newText)).toEqual(["concurrency"]);
+      // One-of (scalar variant)
+      const concurrencyScalar = result.find(x => x.label === "concurrency" && x.labelDetails === undefined);
+      expect(concurrencyScalar?.textEdit?.newText).toEqual("concurrency: ");
     });
 
     it("custom indentation", async () => {
@@ -470,19 +488,411 @@ jobs:
         "timeout-minutes: "
       ]);
 
-      // One-of
-      expect(result.filter(x => x.label === "concurrency").map(x => x.textEdit?.newText)).toEqual(["concurrency"]);
+      // One-of (scalar variant)
+      const concurrencyScalar = result.find(x => x.label === "concurrency" && x.labelDetails === undefined);
+      expect(concurrencyScalar?.textEdit?.newText).toEqual("concurrency: ");
     });
   });
 
-  it("adds a new line and indentation for mapping keys", async () => {
+  it("does not show mapping keys in Key mode for one-of with mapping variant", async () => {
+    // At `concurrency: |`, mapping keys should NOT be shown.
+    // Users who want the mapping form should use `concurrency (full syntax)` at parent level.
     const input = "concurrency: |";
 
     const result = await complete(...getPositionFromCursor(input));
 
-    expect(result.filter(x => x.label === "cancel-in-progress").map(x => x.textEdit?.newText)).toEqual([
-      "\n  cancel-in-progress: "
-    ]);
-    expect(result.filter(x => x.label === "group").map(x => x.textEdit?.newText)).toEqual(["\n  group: "]);
+    expect(result.filter(x => x.label === "cancel-in-progress")).toEqual([]);
+    expect(result.filter(x => x.label === "group")).toEqual([]);
+  });
+
+  it("does not add new line if no key in line", async () => {
+    const input = "run-n|";
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    expect(result.filter(x => x.label === "run-name").map(x => x.textEdit?.newText)).toEqual(["run-name: "]);
+  });
+
+  it("does not show mapping keys when user has started typing a scalar value", async () => {
+    // User typed `workflow_dispatch: in` - they've committed to a scalar value
+    // Should not show mapping keys like `inputs`
+    const input = "on:\n  workflow_dispatch: in|";
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    // No mapping keys should be shown since user started typing a scalar
+    expect(result.filter(x => x.label === "inputs")).toEqual([]);
+  });
+
+  it("adds : for one-of", async () => {
+    const input = "on:\n  check_run:\n    ty|";
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    // Scalar variant inserts "types: "
+    const scalarVariant = result.find(x => x.label === "types" && x.labelDetails === undefined);
+    expect(scalarVariant?.textEdit?.newText).toEqual("types: ");
+  });
+
+  it("does not show mapping keys for one-of when user has typed a scalar value", async () => {
+    // User typed `check_run: ty` - they've committed to scalar form
+    // The only valid value for check_run scalar is null, so no completions
+    const input = "on:\n  check_run: ty|";
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    // check_run's scalar form only accepts null, so typing anything should show no completions
+    // (we don't show mapping keys like `types` anymore - user should use check_run with detail "full syntax" instead)
+    expect(result.filter(x => x.label === "types")).toEqual([]);
+  });
+
+  it("shows only scalar options for one-of in Key mode when user hasn't committed to a type", async () => {
+    // At `permissions: |` user hasn't typed anything yet - show only scalar options
+    // Mapping keys are NOT shown because they would require a newline
+    // Users who want the mapping form can use `permissions (full syntax)` at the parent level
+    const input = "on: push\npermissions: |";
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    // String values (read-all, write-all) should be available
+    expect(result.filter(x => x.label === "read-all").map(x => x.textEdit?.newText)).toEqual(["read-all"]);
+    expect(result.filter(x => x.label === "write-all").map(x => x.textEdit?.newText)).toEqual(["write-all"]);
+
+    // Mapping keys should NOT be shown - they require a newline which is confusing inline
+    expect(result.filter(x => x.label === "actions")).toEqual([]);
+    expect(result.filter(x => x.label === "contents")).toEqual([]);
+  });
+
+  it("filters to scalar options when user has started typing a scalar", async () => {
+    // User typed `permissions: r` - they've committed to scalar form
+    const input = "on: push\npermissions: r|";
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    // Only scalar values should be shown (filtering on 'r')
+    expect(result.some(x => x.label === "read-all")).toBe(true);
+    // Mapping keys should NOT be shown
+    expect(result.filter(x => x.label === "actions")).toEqual([]);
+    expect(result.filter(x => x.label === "contents")).toEqual([]);
+  });
+
+  it("shows both simple and full syntax for null+mapping one-of", async () => {
+    // check_run is a one-of: [null, mapping]. Show both:
+    // - check_run (simple, just the key with colon)
+    // - check_run with detail "full syntax" (ready to add mapping keys)
+    const input = "on:\n  |";
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    // Should have both check_run (scalar) and check_run with detail "full syntax"
+    const checkRunVariants = result.filter(x => x.label === "check_run");
+    expect(checkRunVariants.some(x => x.labelDetails === undefined)).toBe(true);
+    expect(checkRunVariants.some(x => x.labelDetails?.description === "full syntax")).toBe(true);
+  });
+
+  it("shows all three variants for scalar+sequence+mapping one-of", async () => {
+    // runs-on is a one-of: [string, sequence, mapping]
+    const input = `on: push
+jobs:
+  build:
+    |`;
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    // Should have runs-on (scalar), runs-on with detail "list", and runs-on with detail "full syntax"
+    const runsOnVariants = result.filter(x => x.label === "runs-on");
+    expect(runsOnVariants.length).toBe(3);
+    expect(runsOnVariants.some(x => x.labelDetails === undefined)).toBe(true);
+    expect(runsOnVariants.some(x => x.labelDetails?.description === "list")).toBe(true);
+    expect(runsOnVariants.some(x => x.labelDetails?.description === "full syntax")).toBe(true);
+  });
+
+  it("generates correct insertText for one-of variants in parent mode", async () => {
+    // runs-on is a one-of: [string, sequence, mapping]
+    const input = `on: push
+jobs:
+  build:
+    |`;
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    const runsOnVariants = result.filter(x => x.label === "runs-on");
+
+    // Scalar: just key with colon and space
+    expect(runsOnVariants.find(x => x.labelDetails === undefined)?.textEdit?.newText).toEqual("runs-on: ");
+
+    // Sequence: key with colon, newline, and list item
+    expect(runsOnVariants.find(x => x.labelDetails?.description === "list")?.textEdit?.newText).toEqual(
+      "runs-on:\n  - "
+    );
+
+    // Mapping: key with colon, newline, and indentation for nested keys
+    expect(runsOnVariants.find(x => x.labelDetails?.description === "full syntax")?.textEdit?.newText).toEqual(
+      "runs-on:\n  "
+    );
+  });
+
+  it("generates correct insertText for one-of variants in parent mode", async () => {
+    // concurrency is a one-of: [string, mapping] - testing parent mode (inside mapping)
+    // At `concurrency:\n  |`, user HAS committed to mapping structure, so mapping keys are shown
+    const input = "concurrency:\n  |";
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    // In parent mode: just key + colon + space (no leading newline)
+    expect(result.find(x => x.label === "group")?.textEdit?.newText).toEqual("group: ");
+
+    // Boolean in parent mode (cancel-in-progress): key + colon + space
+    expect(result.find(x => x.label === "cancel-in-progress")?.textEdit?.newText).toEqual("cancel-in-progress: ");
+  });
+
+  it("uses sortText for ordering qualified one-of variants", async () => {
+    // runs-on has multiple structural types, so variants need sorting
+    const input = `on: push
+jobs:
+  build:
+    |`;
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    const runsOnVariants = result.filter(x => x.label === "runs-on");
+
+    // Scalar: no sortText needed (sorts naturally first)
+    expect(runsOnVariants.find(x => x.labelDetails === undefined)?.sortText).toBeUndefined();
+
+    // Sequence and mapping: sortText controls ordering
+    expect(runsOnVariants.find(x => x.labelDetails?.description === "list")?.sortText).toEqual("runs-on 1");
+    expect(runsOnVariants.find(x => x.labelDetails?.description === "full syntax")?.sortText).toEqual("runs-on 2");
+  });
+
+  it("scalar event completion inserts inline without newline", async () => {
+    // At `on: |` user is completing the value for 'on' key
+    // Scalar events like `push`, `check_run` should insert inline
+    const input = "on: |";
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    // Scalar forms should NOT have newline - they insert inline
+    const push = result.find(x => x.label === "push");
+    expect(push?.textEdit?.newText).toEqual("push");
+
+    const checkRun = result.find(x => x.label === "check_run" && x.labelDetails === undefined);
+    expect(checkRun?.textEdit?.newText).toEqual("check_run");
+
+    // Full syntax form should NOT be shown in Key mode - it requires a newline
+    // which is confusing when typing inline. Users who want the mapping form
+    // can use `on (full syntax)` at the parent level.
+    expect(result.find(x => x.label === "check_run" && x.labelDetails?.description === "full syntax")).toBeUndefined();
+  });
+
+  it("filters to sequence options when user has started a sequence", async () => {
+    // User started a sequence with `- ` syntax - they've committed to sequence form
+    const input = `on: push
+jobs:
+  build:
+    runs-on:
+      - |`;
+
+    const result = await complete(...getPositionFromCursor(input));
+
+    // Should show runner labels (sequence item values)
+    expect(result.some(x => x.label === "ubuntu-latest")).toBe(true);
+    expect(result.some(x => x.label === "macos-latest")).toBe(true);
+
+    // Should NOT show mapping keys like `group` or `labels` (those are for full syntax)
+    expect(result.filter(x => x.label === "group")).toEqual([]);
+    expect(result.filter(x => x.label === "labels")).toEqual([]);
+  });
+
+  describe("escape hatch completions", () => {
+    it("runs-on shows switch to list and full syntax", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: |`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      // Should have escape hatches at the end
+      const switchToList = result.find(x => x.label === "(switch to list)");
+      const switchToFull = result.find(x => x.label === "(switch to mapping)");
+
+      expect(switchToList).toBeDefined();
+      expect(switchToFull).toBeDefined();
+
+      // Escape hatches should sort last
+      expect(switchToList!.sortText).toEqual("zzz_switch_1");
+      expect(switchToFull!.sortText).toEqual("zzz_switch_2");
+
+      // Escape hatches should have textEdit at cursor position (for VS Code filtering compatibility)
+      const listEdit = switchToList!.textEdit as TextEdit;
+      const fullEdit = switchToFull!.textEdit as TextEdit;
+
+      // Main textEdit inserts newline and indented content at cursor position
+      expect(listEdit.newText).toEqual("\n  - ");
+      expect(fullEdit.newText).toEqual("\n  ");
+
+      // TextEdit range should be at cursor position (empty range)
+      expect(listEdit.range.start).toEqual({line: 3, character: 13});
+      expect(listEdit.range.end).toEqual({line: 3, character: 13});
+      expect(fullEdit.range.start).toEqual({line: 3, character: 13});
+      expect(fullEdit.range.end).toEqual({line: 3, character: 13});
+
+      // additionalTextEdits should clean up the key portion
+      expect(switchToList!.additionalTextEdits).toHaveLength(1);
+      expect(switchToList!.additionalTextEdits![0].range.start).toEqual({line: 3, character: 4});
+      expect(switchToList!.additionalTextEdits![0].range.end).toEqual({line: 3, character: 13});
+      expect(switchToList!.additionalTextEdits![0].newText).toEqual("runs-on:");
+
+      expect(switchToFull!.additionalTextEdits).toHaveLength(1);
+      expect(switchToFull!.additionalTextEdits![0].newText).toEqual("runs-on:");
+    });
+
+    it("permissions shows only switch to full syntax (no sequence form)", async () => {
+      const input = `on: push
+permissions: |`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      // Should have full syntax escape hatch but NOT list (permissions has no sequence form)
+      expect(result.some(x => x.label === "(switch to mapping)")).toBe(true);
+      expect(result.some(x => x.label === "(switch to list)")).toBe(false);
+    });
+
+    it("escape hatches are not shown when value is non-empty", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-|`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      // User has started typing a scalar value, no escape hatches
+      expect(result.some(x => x.label === "(switch to list)")).toBe(false);
+      expect(result.some(x => x.label === "(switch to mapping)")).toBe(false);
+    });
+
+    it("escape hatches are not shown when inside a sequence", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on:
+      - |`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      // User is already in sequence form, no escape hatches
+      expect(result.some(x => x.label === "(switch to list)")).toBe(false);
+      expect(result.some(x => x.label === "(switch to mapping)")).toBe(false);
+    });
+
+    it("escape hatches are not shown when inside a mapping", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on:
+      group: |`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      // User is in mapping form completing a value, no escape hatches for the parent
+      expect(result.some(x => x.label === "(switch to list)")).toBe(false);
+      expect(result.some(x => x.label === "(switch to mapping)")).toBe(false);
+    });
+
+    it("escape hatches ARE shown even when no scalar completions exist", async () => {
+      // concurrency: | has no scalar constants, but escape hatch provides a way out
+      const input = `on: push
+jobs:
+  build:
+    concurrency: |`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      // Escape hatch to mapping should be available even with no scalar completions
+      expect(result.map(x => x.label)).toEqual(["(switch to mapping)"]);
+    });
+
+    it("pure mapping type (strategy) shows switch to mapping", async () => {
+      const input = `on: push
+jobs:
+  build:
+    strategy: |`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      expect(result.some(x => x.label === "(switch to mapping)")).toBe(true);
+    });
+
+    it("pure sequence type (steps) shows switch to list", async () => {
+      const input = `on: push
+jobs:
+  build:
+    steps: |`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      expect(result.some(x => x.label === "(switch to list)")).toBe(true);
+    });
+
+    it("selecting switch to list restructures YAML", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: |`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      const switchToList = result.find(x => x.label === "(switch to list)");
+      const textEdit = switchToList!.textEdit as TextEdit;
+      const additionalEdits = switchToList!.additionalTextEdits!;
+
+      // Main textEdit inserts newline content at cursor
+      expect(textEdit.newText).toEqual("\n  - ");
+
+      // additionalTextEdits replaces "runs-on: " with "runs-on:"
+      expect(additionalEdits).toHaveLength(1);
+      expect(additionalEdits[0].newText).toEqual("runs-on:");
+
+      // Combined result when applied: "runs-on:\n  - "
+    });
+  });
+
+  describe("runs-on mapping syntax", () => {
+    it("provides label completions for labels as scalar", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on:
+      labels: |`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      // Should show runner labels
+      expect(result.some(x => x.label === "ubuntu-latest")).toBe(true);
+      expect(result.some(x => x.label === "macos-latest")).toBe(true);
+      expect(result.some(x => x.label === "self-hosted")).toBe(true);
+    });
+
+    it("provides label completions for labels as sequence item", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on:
+      labels:
+        - |`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      // Should show runner labels
+      expect(result.some(x => x.label === "ubuntu-latest")).toBe(true);
+      expect(result.some(x => x.label === "macos-latest")).toBe(true);
+      expect(result.some(x => x.label === "self-hosted")).toBe(true);
+    });
+
+    it("excludes already used labels in sequence", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on:
+      labels:
+        - ubuntu-latest
+        - |`;
+      const result = await complete(...getPositionFromCursor(input));
+
+      // Should NOT show ubuntu-latest since it's already in the list
+      expect(result.some(x => x.label === "ubuntu-latest")).toBe(false);
+      // But should show other labels
+      expect(result.some(x => x.label === "macos-latest")).toBe(true);
+    });
   });
 });

languageservice/src/complete.ts

@@ -1,30 +1,43 @@
-import {complete as completeExpression, DescriptionDictionary} from "@actions/expressions";
+import {complete as completeExpression, DescriptionDictionary, FeatureFlags} from "@actions/expressions";
 import {CompletionItem as ExpressionCompletionItem} from "@actions/expressions/completion";
 import {isBasicExpression, isSequence, isString} from "@actions/workflow-parser";
+import {getActionSchema} from "@actions/workflow-parser/actions/action-schema";
 import {ErrorPolicy} from "@actions/workflow-parser/model/convert";
+import {DefinitionType} from "@actions/workflow-parser/templates/schema/definition-type";
+import {OneOfDefinition} from "@actions/workflow-parser/templates/schema/one-of-definition";
+import {TemplateSchema} from "@actions/workflow-parser/templates/schema/template-schema";
 import {OPEN_EXPRESSION} from "@actions/workflow-parser/templates/template-constants";
 import {TemplateToken} from "@actions/workflow-parser/templates/tokens/index";
 import {MappingToken} from "@actions/workflow-parser/templates/tokens/mapping-token";
+import {TokenRange} from "@actions/workflow-parser/templates/tokens/token-range";
 import {TokenType} from "@actions/workflow-parser/templates/tokens/types";
 import {File} from "@actions/workflow-parser/workflows/file";
 import {FileProvider} from "@actions/workflow-parser/workflows/file-provider";
+import {getWorkflowSchema} from "@actions/workflow-parser/workflows/workflow-schema";
 import {Position, TextDocument} from "vscode-languageserver-textdocument";
 import {CompletionItem, CompletionItemKind, CompletionItemTag, Range, TextEdit} from "vscode-languageserver-types";
-import {ContextProviderConfig} from "./context-providers/config";
-import {getContext, Mode} from "./context-providers/default";
-import {getWorkflowContext, WorkflowContext} from "./context/workflow-context";
-import {validatorFunctions} from "./expression-validation/functions";
-import {error} from "./log";
-import {isPotentiallyExpression} from "./utils/expression-detection";
-import {findToken} from "./utils/find-token";
-import {guessIndentation} from "./utils/indentation-guesser";
-import {mapRange} from "./utils/range";
-import {getRelCharOffset} from "./utils/rel-char-pos";
-import {isPlaceholder, transform} from "./utils/transform";
-import {fetchOrConvertWorkflowTemplate, fetchOrParseWorkflow} from "./utils/workflow-cache";
-import {Value, ValueProviderConfig} from "./value-providers/config";
-import {defaultValueProviders} from "./value-providers/default";
-import {definitionValues} from "./value-providers/definition";
+import {filterActionRunsCompletions, getActionScaffoldingSnippets} from "./complete-action.js";
+import {ContextProviderConfig} from "./context-providers/config.js";
+import {getActionExpressionContext, getWorkflowExpressionContext, Mode} from "./context-providers/default.js";
+import {ActionContext, getActionContext} from "./context/action-context.js";
+import {getWorkflowContext, WorkflowContext} from "./context/workflow-context.js";
+import {validatorFunctions} from "./expression-validation/functions.js";
+import {error} from "./log.js";
+import {detectDocumentType} from "./utils/document-type.js";
+import {isPotentiallyExpression} from "./utils/expression-detection.js";
+import {findToken} from "./utils/find-token.js";
+import {guessIndentation} from "./utils/indentation-guesser.js";
+import {mapRange} from "./utils/range.js";
+import {isPlaceholder, transform} from "./utils/transform.js";
+import {
+  getOrConvertActionTemplate,
+  getOrConvertWorkflowTemplate,
+  getOrParseAction,
+  getOrParseWorkflow
+} from "./utils/workflow-cache.js";
+import {Value, ValueProviderConfig} from "./value-providers/config.js";
+import {defaultValueProviders} from "./value-providers/default.js";
+import {DefinitionValueMode, definitionValues, TokenStructure} from "./value-providers/definition.js";
 
 export function getExpressionInput(input: string, pos: number): string {
   // Find start marker around the cursor position
@@ -42,6 +55,7 @@ export type CompletionConfig = {
   valueProviderConfig?: ValueProviderConfig;
   contextProviderConfig?: ContextProviderConfig;
   fileProvider?: FileProvider;
+  featureFlags?: FeatureFlags;
 };
 
 export async function complete(
@@ -65,43 +79,96 @@ export async function complete(
     content: newDoc.getText()
   };
 
-  const parsedWorkflow = fetchOrParseWorkflow(file, textDocument.uri, true);
-  if (!parsedWorkflow.value) {
+  // Determine document type - unknown defaults to workflow (backwards compatibility)
+  const isAction = detectDocumentType(textDocument.uri) === "action";
+
+  // Parse the document
+  const parsedTemplate = isAction
+    ? getOrParseAction(file, textDocument.uri, true)
+    : getOrParseWorkflow(file, textDocument.uri, true);
+  if (!parsedTemplate.value) {
     return [];
   }
 
-  const template = await fetchOrConvertWorkflowTemplate(
-    parsedWorkflow.context,
-    parsedWorkflow.value,
-    textDocument.uri,
-    config,
-    {
-      fetchReusableWorkflowDepth: config?.fileProvider ? 1 : 0,
-      errorPolicy: ErrorPolicy.TryConversion
-    }
-  );
+  const schema = isAction ? getActionSchema() : getWorkflowSchema();
+  const {token, keyToken, parent, path} = findToken(newPos, parsedTemplate.value);
 
-  const {token, keyToken, parent, path} = findToken(newPos, parsedWorkflow.value);
-  const workflowContext = getWorkflowContext(textDocument.uri, template, path);
+  // Build context for position-aware completions (e.g., steps.*, needs.*, inputs.*)
+  let workflowContext: WorkflowContext | undefined;
+  let actionContext: ActionContext | undefined;
+  if (isAction) {
+    const actionTemplate = getOrConvertActionTemplate(
+      parsedTemplate.context,
+      parsedTemplate.value,
+      textDocument.uri,
+      {errorPolicy: ErrorPolicy.TryConversion},
+      true
+    );
+    actionContext = getActionContext(textDocument.uri, actionTemplate, path);
+  } else {
+    const workflowTemplate = await getOrConvertWorkflowTemplate(
+      parsedTemplate.context,
+      parsedTemplate.value,
+      textDocument.uri,
+      config,
+      {
+        fetchReusableWorkflowDepth: config?.fileProvider ? 1 : 0,
+        errorPolicy: ErrorPolicy.TryConversion
+      },
+      true
+    );
+    workflowContext = workflowTemplate ? getWorkflowContext(textDocument.uri, workflowTemplate, path) : undefined;
+  }
 
-  // If we are inside an expression, take a different code-path. The workflow parser does not correctly create
-  // expression nodes for invalid expressions and during editing expressions are invalid most of the time.
-  if (token) {
-    if (isBasicExpression(token) || isPotentiallyExpression(token)) {
-      const allowedContext = token.definitionInfo?.allowedContext || [];
-      const context = await getContext(allowedContext, config?.contextProviderConfig, workflowContext, Mode.Completion);
+  // Expression completions
+  if (token && (isBasicExpression(token) || isPotentiallyExpression(token))) {
+    const allowedContext = token.definitionInfo?.allowedContext || [];
+    const context = isAction
+      ? getActionExpressionContext(allowedContext, config?.contextProviderConfig, actionContext, Mode.Completion)
+      : await getWorkflowExpressionContext(
+          allowedContext,
+          config?.contextProviderConfig,
+          workflowContext,
+          Mode.Completion
+        );
 
-      return getExpressionCompletionItems(token, context, newPos);
-    }
+    return getExpressionCompletionItems(token, context, newPos);
   }
 
   const indentation = guessIndentation(newDoc, 2, true); // Use 2 spaces as default and most common for YAML
   const indentString = " ".repeat(indentation.tabSize);
 
-  const values = await getValues(token, keyToken, parent, config?.valueProviderConfig, workflowContext, indentString);
+  // YAML key/value completions
+  let values = await getValues(
+    token,
+    keyToken,
+    parent,
+    config?.valueProviderConfig,
+    workflowContext,
+    indentString,
+    schema
+  );
 
+  // Filter action.yml `runs:` completions based on `using:` value
+  if (isAction && parsedTemplate.value) {
+    values = filterActionRunsCompletions(values, path, parsedTemplate.value);
+  }
+
+  // Offer "(switch to list)" / "(switch to mapping)" when the schema allows alternative forms
+  const escapeHatches = getEscapeHatchCompletions(token, keyToken, indentString, newPos, schema);
+  values.push(...escapeHatches);
+
+  // Get action scaffolding snippets if applicable
+  let actionSnippets: CompletionItem[] = [];
+  if (isAction && config?.featureFlags?.isEnabled("actionScaffoldingSnippets")) {
+    actionSnippets = getActionScaffoldingSnippets(parsedTemplate.value, path, position);
+  }
+
+  // Figure out what text to replace when the user picks a completion.
+  // For example, if they typed `runs-|` and pick `runs-on`, we need to replace `runs-`.
   let replaceRange: Range | undefined;
   if (token?.range) {
+    // Prefer the token's range since it accounts for YAML syntax like quotes
     replaceRange = mapRange(token.range);
   } else if (!token) {
     // Not a valid token, create a range from the current position
@@ -124,30 +191,66 @@ export async function complete(
     }
   }
 
-  return values.map(value => {
+  // Convert values to LSP CompletionItems
+  const completionItems = values.map(value => {
     const newText = value.insertText || value.label;
 
+    // Escape hatches provide their own textEdit to restructure the YAML
+    let textEdit: TextEdit;
+    if (value.textEdit) {
+      textEdit = TextEdit.replace(value.textEdit.range, value.textEdit.newText);
+    } else if (replaceRange) {
+      textEdit = TextEdit.replace(replaceRange, newText);
+    } else {
+      textEdit = TextEdit.insert(position, newText);
+    }
+
+    // Convert additionalTextEdits if present
+    let additionalTextEdits: TextEdit[] | undefined;
+    if (value.additionalTextEdits) {
+      additionalTextEdits = value.additionalTextEdits.map(edit => TextEdit.replace(edit.range, edit.newText));
+    }
+
     const item: CompletionItem = {
       label: value.label,
+      labelDetails: value.labelDetail ? {description: value.labelDetail} : undefined,
+      filterText: value.filterText,
+      sortText: value.sortText,
       documentation: value.description && {
         kind: "markdown",
         value: value.description
       },
       tags: value.deprecated ? [CompletionItemTag.Deprecated] : undefined,
-      textEdit: replaceRange ? TextEdit.replace(replaceRange, newText) : TextEdit.insert(position, newText)
+      textEdit,
+      additionalTextEdits
     };
 
     return item;
   });
+
+  // Add action scaffolding snippets if available
+  return [...completionItems, ...actionSnippets];
 }
 
+/**
+ * Retrieves completion values for a token based on value providers and definitions.
+ *
+ * This function determines which values to suggest for auto-completion by:
+ * 1. First checking for custom value providers configured for the token's definition key
+ * 2. Then checking for default value providers for the token's definition key
+ * 3. Finally falling back to values derived from the token's schema definition
+ *
+ * The results are filtered to exclude duplicates (e.g., keys already defined in a mapping
+ * or values already present in a sequence) and sorted alphabetically.
+ */
 async function getValues(
   token: TemplateToken | null,
   keyToken: TemplateToken | null,
   parent: TemplateToken | null,
   valueProviderConfig: ValueProviderConfig | undefined,
-  workflowContext: WorkflowContext,
-  indentation: string
+  workflowContext: WorkflowContext | undefined,
+  indentation: string,
+  schema: TemplateSchema
 ): Promise<Value[]> {
   if (!parent) {
     return [];
@@ -158,20 +261,23 @@ async function getValues(
   // Use the value providers from the parent if the current key is null
   const valueProviderToken = keyToken || parent;
 
-  const customValueProvider =
-    valueProviderToken?.definition?.key && valueProviderConfig?.[valueProviderToken.definition.key];
-  if (customValueProvider) {
-    const customValues = await customValueProvider.get(workflowContext, existingValues);
-    if (customValues) {
-      return filterAndSortCompletionOptions(customValues, existingValues);
+  // Value providers require workflow context - only use them for workflows
+  if (workflowContext) {
+    const customValueProvider =
+      valueProviderToken?.definition?.key && valueProviderConfig?.[valueProviderToken.definition.key];
+    if (customValueProvider) {
+      const customValues = await customValueProvider.get(workflowContext, existingValues);
+      if (customValues) {
+        return filterAndSortCompletionOptions(customValues, existingValues);
+      }
     }
-  }
 
-  const defaultValueProvider =
-    valueProviderToken?.definition?.key && defaultValueProviders[valueProviderToken.definition.key];
-  if (defaultValueProvider) {
-    const values = await defaultValueProvider.get(workflowContext, existingValues);
-    return filterAndSortCompletionOptions(values, existingValues);
+    const defaultValueProvider =
+      valueProviderToken?.definition?.key && defaultValueProviders[valueProviderToken.definition.key];
+    if (defaultValueProvider) {
+      const values = await defaultValueProvider.get(workflowContext, existingValues);
+      return filterAndSortCompletionOptions(values, existingValues);
+    }
   }
 
   // Use the definition if there are no value providers
@@ -180,10 +286,202 @@ async function getValues(
     return [];
   }
 
-  const values = definitionValues(def, indentation);
+  // When a schema allows multiple formats (e.g., `runs-on` can be a string OR a mapping),
+  // only suggest completions that match what the user has already started typing.
+  // For example, if they've started a mapping, don't suggest string values.
+  const tokenStructure = getTokenStructure(token);
+  const values = definitionValues(
+    def,
+    indentation,
+    keyToken ? DefinitionValueMode.Key : DefinitionValueMode.Parent,
+    tokenStructure,
+    schema
+  );
   return filterAndSortCompletionOptions(values, existingValues);
 }
 
+/**
+ * Determines what YAML structure the user has committed to, if any.
+ *
+ * Returns:
+ * - "mapping" if the user has started a key-value structure (e.g., `runs-on:\n  group: |`)
+ * - "sequence" if the user has started a list (e.g., `runs-on:\n  - |`)
+ * - "scalar" if the user has started typing a plain value (e.g., `runs-on: ubuntu-|`)
+ * - undefined if the user hasn't committed yet (e.g., `runs-on: |` with nothing typed)
+ */
+function getTokenStructure(token: TemplateToken | null): TokenStructure {
+  if (!token) {
+    return undefined;
+  }
+
+  switch (token.templateTokenType) {
+    case TokenType.Mapping:
+      return "mapping";
+    case TokenType.Sequence:
+      return "sequence";
+    case TokenType.Null:
+      // Null means `key: ` with nothing - user hasn't committed to a type yet
+      return undefined;
+    case TokenType.String: {
+      // Empty string means `key: |` - user hasn't committed yet
+      // Non-empty string means user has started typing a scalar value
+      const stringToken = token.assertString("getTokenStructure expected string token");
+      if (stringToken.value === "") {
+        return undefined;
+      }
+      return "scalar";
+    }
+    case TokenType.Boolean:
+    case TokenType.Number:
+      return "scalar";
+    default:
+      return undefined;
+  }
+}
+
+/**
+ * Generates escape hatch completions that allow switching from scalar form to
+ * alternative structural forms (sequence or mapping) when the value is empty.
+ *
+ * For example, at `runs-on: |`, this adds "(switch to list)" and "(switch to full syntax)"
+ * completions that restructure the YAML to `runs-on:\n  - |` or `runs-on:\n  |`.
+ *
+ * Only shown when:
+ * - Completing in value position (keyToken exists)
+ * - Value is empty (user hasn't committed to a structure yet)
+ * - Definition allows sequence or mapping structure
+ */
+function getEscapeHatchCompletions(
+  token: TemplateToken | null,
+  keyToken: TemplateToken | null,
+  indentation: string,
+  position: Position,
+  schema: TemplateSchema
+): Value[] {
+  // Only show escape hatches when value is empty
+  const tokenStructure = getTokenStructure(token);
+  if (tokenStructure !== undefined) {
+    return [];
+  }
+
+  // Need a key token with a definition
+  if (!keyToken?.definition) {
+    return [];
+  }
+
+  // Determine which structural types are available from the definition
+  const def = keyToken.definition;
+  const buckets = {
+    sequence: false,
+    mapping: false
+  };
+
+  if (def instanceof OneOfDefinition) {
+    // OneOf: check each variant
+    for (const variantKey of def.oneOf) {
+      const variantDef = schema.definitions[variantKey];
+      if (variantDef) {
+        switch (variantDef.definitionType) {
+          case DefinitionType.Sequence:
+            buckets.sequence = true;
+            break;
+          case DefinitionType.Mapping:
+            buckets.mapping = true;
+            break;
+        }
+      }
+    }
+  } else {
+    // Single definition type
+    switch (def.definitionType) {
+      case DefinitionType.Sequence:
+        buckets.sequence = true;
+        break;
+      case DefinitionType.Mapping:
+        buckets.mapping = true;
+        break;
+    }
+  }
+
+  const results: Value[] = [];
+  const keyName = isString(keyToken) ? keyToken.value : "";
+  const keyRange = keyToken.range;
+
+  if (!keyRange || !keyName) {
+    return [];
+  }
+
+  // For VS Code compatibility, we use a cursor-position range for the main textEdit
+  // and additionalTextEdits to clean up the key portion. This prevents VS Code from
+  // filtering out escape hatches based on the key text (e.g., "runs-on: ").
+  //
+  // Main textEdit: insert at cursor position (newline + indented content)
+  // additionalTextEdits: replace "key: " with "key:" (removes trailing space)
+  const cursorRange = {
+    start: {line: position.line, character: position.character},
+    end: {line: position.line, character: position.character}
+  };
+
+  // Range from key start to cursor - used to replace "key: " with "key:" in additionalTextEdits
+  const keyToCursorRange = {
+    start: {line: keyRange.start.line - 1, character: keyRange.start.column - 1},
+    end: {line: position.line, character: position.character}
+  };
+
+  if (buckets.sequence) {
+    results.push({
+      label: "(switch to list)",
+      sortText: "zzz_switch_1",
+      textEdit: {
+        range: cursorRange,
+        newText: `\n${indentation}- `
+      },
+      additionalTextEdits: [
+        {
+          range: keyToCursorRange,
+          newText: `${keyName}:`
+        }
+      ]
+    });
+  }
+
+  if (buckets.mapping) {
+    results.push({
+      label: "(switch to mapping)",
+      sortText: "zzz_switch_2",
+      textEdit: {
+        range: cursorRange,
+        newText: `\n${indentation}`
+      },
+      additionalTextEdits: [
+        {
+          range: keyToCursorRange,
+          newText: `${keyName}:`
+        }
+      ]
+    });
+  }
+
+  return results;
+}
+
+/**
+ * Collects values that are already present in the current context, so they can be
+ * excluded from completion suggestions.
+ *
+ * For sequences (lists), returns all existing items. For example, if the user has:
+ *   labels:
+ *     - bug
+ *     - |
+ * This returns {"bug"} so we don't suggest "bug" again.
+ *
+ * For mappings, returns all existing keys. For example, if the user has:
+ *   jobs:
+ *     build:
+ *       runs-on: ubuntu-latest
+ *       |
+ * This returns {"runs-on"} so we don't suggest "runs-on" again.
+ */
 export function getExistingValues(token: TemplateToken | null, parent: TemplateToken) {
   // For incomplete YAML, we may only have a parent token
   if (token) {
@@ -238,12 +536,12 @@ function getExpressionCompletionItems(
     currentInput = stringToken.source || stringToken.value;
   }
 
-  const relCharOffset = getRelCharOffset(token.range, currentInput, pos);
-  const expressionInput = (getExpressionInput(currentInput, relCharOffset) || "").trim();
+  const cursorOffset = getOffsetInContent(token.range, currentInput, pos);
+  const expressionInput = (getExpressionInput(currentInput, cursorOffset) || "").trim();
 
   try {
     return completeExpression(expressionInput, context, [], validatorFunctions).map(item =>
-      mapExpressionCompletionItem(item, currentInput[relCharOffset])
+      mapExpressionCompletionItem(item, currentInput[cursorOffset])
     );
   } catch (e) {
     error(`Error while completing expression: '${(e as Error)?.message || "<no details>"}'`);
@@ -253,7 +551,7 @@ function getExpressionCompletionItems(
 
 function filterAndSortCompletionOptions(options: Value[], existingValues?: Set<string>) {
   options = options.filter(x => !existingValues?.has(x.label));
-  options.sort((a, b) => a.label.localeCompare(b.label));
+  options.sort((a, b) => (a.sortText ?? a.label).localeCompare(b.sortText ?? b.label));
   return options;
 }
 
@@ -274,3 +572,50 @@ function mapExpressionCompletionItem(item: ExpressionCompletionItem, charAfterPo
     kind: item.function ? CompletionItemKind.Function : CompletionItemKind.Variable
   };
 }
+
+/**
+ * Converts a document position to an offset within the token's content string.
+ */
+function getOffsetInContent(tokenRange: TokenRange, currentInput: string, pos: Position): number {
+  const range = mapRange(tokenRange);
+
+  if (range.start.line === range.end.line) {
+    // Single-line example:
+    //   if: github.ref == 'main'
+    //       ^8      ^15 (cursor)
+    // currentInput = "github.ref == 'main'"
+    // offset = 15 - 8 = 7
+    return pos.character - range.start.character;
+  }
+
+  // Multi-line example:
+  //   if: |                         <- line 3 (range.start.line)
+  //     first line                  <- line 4, content line 0
+  //     second line                 <- line 5, content line 1
+  //     github.                     <- line 6, content line 2, cursor at index 11
+  //            ^11 (cursor)
+  //
+  // currentInput = "    first line\n    second line\n    github."
+  //                 ^0              ^15              ^32        ^43
+
+  // Line index within content.
+  // From the example:
+  // lineIndexWithinContent = pos.line - range.start.line - 1
+  //                        = 6 - 3 - 1 = 2
+  const lineIndexWithinContent = pos.line - range.start.line - 1;
+
+  // Length of content before current line.
+  // From the example:
+  // lengthOfContentBeforeCurrentLine => 14 + 1 = 15 (after first iteration)
+  //                                  => 31 + 1 = 32 (after second iteration)
+  let lengthOfContentBeforeCurrentLine = 0;
+  for (let i = 0; i < lineIndexWithinContent; i++) {
+    lengthOfContentBeforeCurrentLine = currentInput.indexOf("\n", lengthOfContentBeforeCurrentLine) + 1;
+  }
+
+  // Final offset within content.
+  // From the example:
+  // finalOffset = lengthOfContentBeforeCurrentLine + pos.character
+  //             = 32 + 11 = 43
+  return lengthOfContentBeforeCurrentLine + pos.character;
+}

languageservice/src/context-providers/config.ts

@@ -1,6 +1,6 @@
 import {DescriptionDictionary} from "@actions/expressions";
-import {WorkflowContext} from "../context/workflow-context";
-import {Mode} from "./default";
+import {WorkflowContext} from "../context/workflow-context.js";
+import {Mode} from "./default.js";
 
 export type ContextProviderConfig = {
   getContext: (

languageservice/src/context-providers/default.test.ts

@@ -0,0 +1,102 @@
+import {DescriptionDictionary} from "@actions/expressions";
+import {WorkflowContext} from "../context/workflow-context.js";
+import {getWorkflowExpressionContext, Mode} from "./default.js";
+
+describe("getWorkflowExpressionContext", () => {
+  const emptyWorkflowContext: WorkflowContext = {
+    uri: "test.yaml",
+    template: undefined
+  };
+
+  describe("when no contextProviderConfig is provided", () => {
+    it("should mark secrets context as incomplete", async () => {
+      const result = await getWorkflowExpressionContext(["secrets"], undefined, emptyWorkflowContext, Mode.Validation);
+
+      const secretsContext = result.get("secrets") as DescriptionDictionary;
+      expect(secretsContext).toBeDefined();
+      expect(secretsContext.complete).toBe(false);
+    });
+
+    it("should mark vars context as incomplete", async () => {
+      const result = await getWorkflowExpressionContext(["vars"], undefined, emptyWorkflowContext, Mode.Validation);
+
+      const varsContext = result.get("vars") as DescriptionDictionary;
+      expect(varsContext).toBeDefined();
+      expect(varsContext.complete).toBe(false);
+    });
+
+    it("should not mark other contexts as incomplete", async () => {
+      const result = await getWorkflowExpressionContext(
+        ["env", "github"],
+        undefined,
+        emptyWorkflowContext,
+        Mode.Validation
+      );
+
+      const envContext = result.get("env") as DescriptionDictionary;
+      const githubContext = result.get("github") as DescriptionDictionary;
+
+      // These contexts are derived from the workflow file, so they can be complete
+      expect(envContext).toBeDefined();
+      expect(envContext.complete).toBe(true);
+      expect(githubContext).toBeDefined();
+      expect(githubContext.complete).toBe(true);
+    });
+  });
+
+  describe("when contextProviderConfig returns a value", () => {
+    it("should use the provided context for secrets", async () => {
+      const providedContext = new DescriptionDictionary();
+      providedContext.complete = true; // Provider fetched from API, so it's complete
+
+      const config = {
+        getContext: () => Promise.resolve(providedContext)
+      };
+
+      const result = await getWorkflowExpressionContext(["secrets"], config, emptyWorkflowContext, Mode.Validation);
+
+      const secretsContext = result.get("secrets");
+      expect(secretsContext).toBe(providedContext);
+      expect((secretsContext as DescriptionDictionary).complete).toBe(true);
+    });
+
+    it("should use the provided context for vars", async () => {
+      const providedContext = new DescriptionDictionary();
+      providedContext.complete = true;
+
+      const config = {
+        getContext: () => Promise.resolve(providedContext)
+      };
+
+      const result = await getWorkflowExpressionContext(["vars"], config, emptyWorkflowContext, Mode.Validation);
+
+      const varsContext = result.get("vars");
+      expect(varsContext).toBe(providedContext);
+      expect((varsContext as DescriptionDictionary).complete).toBe(true);
+    });
+  });
+
+  describe("when contextProviderConfig returns undefined", () => {
+    it("should mark secrets as incomplete", async () => {
+      const config = {
+        getContext: () => Promise.resolve(undefined)
+      };
+
+      const result = await getWorkflowExpressionContext(["secrets"], config, emptyWorkflowContext, Mode.Validation);
+
+      const secretsContext = result.get("secrets") as DescriptionDictionary;
+      expect(secretsContext.complete).toBe(false);
+    });
+
+    it("should mark vars as incomplete", async () => {
+      const config = {
+        getContext: () => Promise.resolve(undefined)
+      };
+
+      const result = await getWorkflowExpressionContext(["vars"], config, emptyWorkflowContext, Mode.Validation);
+
+      const varsContext = result.get("vars") as DescriptionDictionary;
+      expect(varsContext.complete).toBe(false);
+    });
+  });
+});

languageservice/src/context-providers/default.ts

@@ -1,18 +1,18 @@
 import {data, DescriptionDictionary} from "@actions/expressions";
 import {Kind} from "@actions/expressions/data/expressiondata";
-import {WorkflowContext} from "../context/workflow-context";
-import {ContextProviderConfig} from "./config";
-import {getDescription, RootContext} from "./descriptions";
-import {getEnvContext} from "./env";
-import {getGithubContext} from "./github";
-import {getInputsContext} from "./inputs";
-import {getJobContext} from "./job";
-import {getJobsContext} from "./jobs";
-import {getMatrixContext} from "./matrix";
-import {getNeedsContext} from "./needs";
-import {getSecretsContext} from "./secrets";
-import {getStepsContext} from "./steps";
-import {getStrategyContext} from "./strategy";
+import {ActionContext, getActionInputs, getActionStepIdsBefore} from "../context/action-context.js";
+import {WorkflowContext} from "../context/workflow-context.js";
+import {ContextProviderConfig} from "./config.js";
+import {getDescription, RootContext} from "./descriptions.js";
+import {getEnvContext} from "./env.js";
+import {getGithubContext} from "./github.js";
+import {getInputsContext} from "./inputs.js";
+import {getJobContext} from "./job.js";
+import {getJobsContext} from "./jobs.js";
+import {getMatrixContext} from "./matrix.js";
+import {getNeedsContext} from "./needs.js";
+import {getSecretsContext} from "./secrets.js";
+import {getStepsContext} from "./steps.js";
 
 // ContextValue is the type of the value returned by a context provider
 // Null indicates that the context provider doesn't have any value to provide
@@ -24,23 +24,37 @@ export enum Mode {
   Hover
 }
 
-export async function getContext(
+/**
+ * Build expression context for workflow files (e.g., github.*, steps.*, needs.*)
+ */
+export async function getWorkflowExpressionContext(
   names: string[],
   config: ContextProviderConfig | undefined,
-  workflowContext: WorkflowContext,
+  workflowContext: WorkflowContext | undefined,
   mode: Mode
 ): Promise<DescriptionDictionary> {
   const context = new DescriptionDictionary();
 
-  const filteredNames = filterContextNames(names, workflowContext);
-  for (const contextName of filteredNames) {
+  // All context names are valid - strategy and matrix are always available
+  // (with default values when no strategy block is defined)
+  for (const contextName of names) {
     let value = getDefaultContext(contextName, workflowContext, mode) || new DescriptionDictionary();
     if (value.kind === Kind.Null) {
       context.add(contextName, value);
       continue;
     }
 
-    value = (await config?.getContext(contextName, value, workflowContext, mode)) || value;
+    const remoteValue = workflowContext
+      ? await config?.getContext(contextName, value, workflowContext, mode)
+      : undefined;
+    if (remoteValue) {
+      value = remoteValue;
+    } else if (contextName === "secrets" || contextName === "vars") {
+      // Without a context provider to fetch remote secrets/vars, we can't know
+      // what values exist, so mark the context as incomplete to avoid false
+      // "Context access might be invalid" warnings
+      value.complete = false;
+    }
 
     context.add(contextName, value, getDescription(RootContext, contextName));
   }
@@ -48,73 +62,198 @@ export async function getContext(
   return context;
 }
 
-function getDefaultContext(name: string, workflowContext: WorkflowContext, mode: Mode): ContextValue | undefined {
+/**
+ * Maps context name to its provider (e.g., "steps" -> getStepsContext)
+ */
+function getDefaultContext(
+  name: string,
+  workflowContext: WorkflowContext | undefined,
+  mode: Mode
+): ContextValue | undefined {
   switch (name) {
     case "env":
-      return getEnvContext(workflowContext);
+      return workflowContext ? getEnvContext(workflowContext) : new DescriptionDictionary();
 
     case "github":
       return getGithubContext(workflowContext, mode);
 
     case "inputs":
-      return getInputsContext(workflowContext);
+      return workflowContext ? getInputsContext(workflowContext) : new DescriptionDictionary();
 
     case "reusableWorkflowJob":
     case "job":
-      return getJobContext(workflowContext);
+      return workflowContext ? getJobContext(workflowContext) : new DescriptionDictionary();
 
     case "jobs":
-      return getJobsContext(workflowContext);
+      return workflowContext ? getJobsContext(workflowContext) : new DescriptionDictionary();
 
     case "matrix":
-      return getMatrixContext(workflowContext, mode);
+      return workflowContext ? getMatrixContext(workflowContext, mode) : new DescriptionDictionary();
 
     case "needs":
-      return getNeedsContext(workflowContext);
+      return workflowContext ? getNeedsContext(workflowContext) : new DescriptionDictionary();
 
     case "runner":
-      return objectToDictionary({
-        os: "Linux",
-        arch: "X64",
-        name: "GitHub Actions 2",
-        tool_cache: "/opt/hostedtoolcache",
-        temp: "/home/runner/work/_temp"
-      });
+      return getRunnerContext();
 
     case "secrets":
-      return getSecretsContext(workflowContext, mode);
+      return workflowContext ? getSecretsContext(workflowContext, mode) : new DescriptionDictionary();
 
     case "steps":
-      return getStepsContext(workflowContext);
+      return workflowContext ? getStepsContext(workflowContext) : new DescriptionDictionary();
 
     case "strategy":
-      return getStrategyContext(workflowContext);
+      return getStrategyContext();
   }
 
   return undefined;
 }
 
-function objectToDictionary(object: {[key: string]: string}): DescriptionDictionary {
-  const dictionary = new DescriptionDictionary();
+/**
+ * Returns the strategy context with default values (fail-fast, job-index, etc.)
+ */
+function getStrategyContext(): DescriptionDictionary {
+  // https://docs.github.com/en/actions/learn-github-actions/contexts#strategy-context
+  return new DescriptionDictionary(
+    {key: "fail-fast", value: new data.BooleanData(true), description: getDescription("strategy", "fail-fast")},
+    {key: "job-index", value: new data.NumberData(0), description: getDescription("strategy", "job-index")},
+    {key: "job-total", value: new data.NumberData(1), description: getDescription("strategy", "job-total")},
+    {key: "max-parallel", value: new data.NumberData(1), description: getDescription("strategy", "max-parallel")}
+  );
+}
 
-  for (const key in object) {
-    dictionary.add(key, new data.StringData(object[key]));
+/**
+ * Returns the runner context with environment info (arch, os, temp, workspace, etc.)
+ */
+function getRunnerContext(): DescriptionDictionary {
+  // https://docs.github.com/en/actions/learn-github-actions/contexts#runner-context
+  return new DescriptionDictionary(
+    {key: "arch", value: new data.StringData("X64"), description: getDescription("runner", "arch")},
+    {key: "debug", value: new data.StringData("1"), description: getDescription("runner", "debug")},
+    {
+      key: "environment",
+      value: new data.StringData("github-hosted"),
+      description: getDescription("runner", "environment")
+    },
+    {key: "name", value: new data.StringData("GitHub Actions 2"), description: getDescription("runner", "name")},
+    {key: "os", value: new data.StringData("Linux"), description: getDescription("runner", "os")},
+    {key: "temp", value: new data.StringData("/home/runner/work/_temp"), description: getDescription("runner", "temp")},
+    {
+      key: "tool_cache",
+      value: new data.StringData("/opt/hostedtoolcache"),
+      description: getDescription("runner", "tool_cache")
+    },
+    {
+      key: "workspace",
+      value: new data.StringData("/home/runner/work/repo"),
+      description: getDescription("runner", "workspace")
+    }
+  );
+}
+
+/**
+ * Get context for expression completion in action.yml files.
+ * Actions have a more limited set of contexts available compared to workflows.
+ */
+export function getActionExpressionContext(
+  names: string[],
+  config: ContextProviderConfig | undefined,
+  actionContext: ActionContext | undefined,
+  mode: Mode
+): DescriptionDictionary {
+  const context = new DescriptionDictionary();
+
+  for (const contextName of names) {
+    const value = getDefaultActionContext(contextName, actionContext, mode);
+    if (value) {
+      context.add(contextName, value, getDescription(RootContext, contextName));
+    }
   }
 
-  return dictionary;
+  return context;
 }
 
-function filterContextNames(contextNames: string[], workflowContext: WorkflowContext): string[] {
-  return contextNames.filter(name => {
-    switch (name) {
-      case "matrix":
-      case "strategy":
-        return hasStrategy(workflowContext);
+/**
+ * Maps context name to its provider for action.yml files (e.g., "inputs" -> getActionInputsContext)
+ */
+function getDefaultActionContext(
+  name: string,
+  actionContext: ActionContext | undefined,
+  mode: Mode
+): ContextValue | undefined {
+  switch (name) {
+    case "inputs":
+      // Return empty dictionary if no context - still allows completion, just without specific input names
+      return actionContext ? getActionInputsContext(actionContext) : new DescriptionDictionary();
+
+    case "steps":
+      // Return empty dictionary if no context - still allows completion, just without specific step IDs
+      return actionContext ? getActionStepsContext(actionContext) : new DescriptionDictionary();
+
+    case "github":
+      // Use the same github context but without workflow-specific event info
+      // Actions inherit the event context from the calling workflow at runtime
+      return getGithubContext(undefined, mode);
+
+    case "runner":
+      return getRunnerContext();
+
+    case "env":
+      // Actions can access env but we don't have runtime values
+      return new DescriptionDictionary();
+
+    case "job": {
+      // https://docs.github.com/en/actions/learn-github-actions/contexts#job-context
+      const jobContext = new DescriptionDictionary();
+      jobContext.add("status", new data.StringData(""), getDescription("job", "status"));
+      jobContext.add("check_run_id", new data.StringData(""), getDescription("job", "check_run_id"));
+      const containerContext = new DescriptionDictionary();
+      containerContext.add("id", new data.StringData(""), getDescription("job", "container.id"));
+      containerContext.add("network", new data.StringData(""), getDescription("job", "container.network"));
+      jobContext.add("container", containerContext, getDescription("job", "container"));
+      jobContext.add("services", new DescriptionDictionary(), getDescription("job", "services"));
+      return jobContext;
     }
-    return true;
-  });
+
+    case "strategy":
+      return getStrategyContext();
+
+    case "matrix":
+      // Actions can access matrix context at runtime
+      return new DescriptionDictionary();
+  }
+
+  return undefined;
 }
 
-function hasStrategy(workflowContext: WorkflowContext): boolean {
-  return workflowContext.job?.strategy !== undefined || workflowContext.reusableWorkflowJob?.strategy !== undefined;
+/**
+ * Get inputs context for action files based on defined inputs
+ */
+function getActionInputsContext(actionContext: ActionContext): DescriptionDictionary {
+  const dict = new DescriptionDictionary();
+  const inputs = getActionInputs(actionContext.template);
+
+  for (const input of inputs) {
+    dict.add(input.id, new data.StringData(""), input.description || "");
+  }
+
+  return dict;
+}
+
+/**
+ * Get steps context for composite action files based on step IDs
+ */
+function getActionStepsContext(actionContext: ActionContext): DescriptionDictionary {
+  const dict = new DescriptionDictionary();
+  const stepIds = getActionStepIdsBefore(actionContext);
+
+  for (const stepId of stepIds) {
+    const stepDict = new DescriptionDictionary();
+    stepDict.add("outputs", new DescriptionDictionary(), getDescription("steps", "outputs"));
+    stepDict.add("outcome", new data.StringData("success"), getDescription("steps", "outcome"));
+    stepDict.add("conclusion", new data.StringData("success"), getDescription("steps", "conclusion"));
+    dict.add(stepId, stepDict, `Step: ${stepId}`);
+  }
+
+  return dict;
 }

languageservice/src/context-providers/descriptions.json

@@ -49,15 +49,15 @@
       "description": "Returns `true` when any previous step of a job fails. If you have a chain of dependent jobs, `failure()` returns `true` if any ancestor job fails."
     },
     "hashFiles": {
-      "description": "Returns a single hash for the set of files that matches the `path` pattern. You can provide a single `path` pattern or multiple `path` patterns separated by commas. The `path` is relative to the `GITHUB_WORKSPACE` directory and can only include files inside of the `GITHUB_WORKSPACE`."
+      "description": "Returns a single hash for the set of files that matches the `path` pattern. You can provide a single `path` pattern or multiple `path` patterns separated by commas. The `path` is relative to the `GITHUB_WORKSPACE` directory and can only include files inside of the `GITHUB_WORKSPACE`. This function calculates an individual SHA-256 hash for each matched file, and then uses those hashes to calculate a final SHA-256 hash for the set of files. If the `path` pattern does not match any files, this returns an empty string. For more information about SHA-256, see \"[SHA-2](https://wikipedia.org/wiki/SHA-2).\"\n\nYou can use pattern matching characters to match file names. Pattern matching is case-insensitive on Windows. For more information about supported pattern matching characters, see \"[Workflow syntax for GitHub Actions](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#filter-pattern-cheat-sheet).\""
     }
   },
   "github": {
     "action": {
-      "description": "The name of the action currently running, or the [`id`](https://docs.github.com/actions/learn-github-actions/workflow-syntax-for-github-actions#jobsjob_idstepsid) of a step. GitHub Actions removes special characters, and uses the name `__run` when the current step runs a script without an `id`. If you use the same action more than once in the same job, the name will include a suffix with the sequence number with underscore before it. For example, the first script you run will have the name `__run`, and the second script will be named `__run_2`. Similarly, the second invocation of `actions/checkout` will be `actionscheckout2`."
+      "description": "The name of the action currently running, or the [`id`](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsid) of a step. GitHub removes special characters, and uses the name `__run` when the current step runs a script without an `id`. If you use the same action more than once in the same job, the name will include a suffix with the sequence number with underscore before it. For example, the first script you run will have the name `__run`, and the second script will be named `__run_2`. Similarly, the second invocation of `actions/checkout` will be `actionscheckout2`."
     },
     "action_path": {
-      "description": "The path where an action is located. This property is only supported in composite actions. You can use this path to access files located in the same repository as the action."
+      "description": "The path where an action is located. This property is only supported in composite actions. You can use this path to access files located in the same repository as the action, for example by changing directories to the path: `cd ${{ github.action_path }}`."
     },
     "action_ref": {
       "description": "For a step executing an action, this is the ref of the action being executed. For example, `v2`."
@@ -71,17 +71,24 @@
     "actor": {
       "description": "The username of the user that triggered the initial workflow run. If the workflow run is a re-run, this value may differ from `github.triggering_actor`. Any workflow re-runs will use the privileges of `github.actor`, even if the actor initiating the re-run (`github.triggering_actor`) has different privileges."
     },
+    "actor_id": {
+      "description": "The account ID of the person or app that triggered the initial workflow run. For example, `1234567`. Note that this is different from the actor username.",
+      "versions": {
+        "ghes": ">=3.9",
+        "ghae": ">=3.9"
+      }
+    },
     "api_url": {
-      "description": "The URL of the GitHub Actions REST API."
+      "description": "The URL of the GitHub REST API."
     },
     "base_ref": {
       "description": "The `base_ref` or target branch of the pull request in a workflow run. This property is only available when the event that triggers a workflow run is either `pull_request` or `pull_request_target`."
     },
     "env": {
-      "description": "Path on the runner to the file that sets environment variables from workflow commands. This file is unique to the current step and is a different file for each step in a job. For more information, see [Workflow commands](https://docs.github.com/actions/learn-github-actions/workflow-commands-for-github-actions#setting-an-environment-variable)."
+      "description": "Path on the runner to the file that sets environment variables from workflow commands. This file is unique to the current step and is a different file for each step in a job. For more information, see \"[Workflow commands for GitHub Actions](https://docs.github.com/actions/using-workflows/workflow-commands-for-github-actions#setting-an-environment-variable).\""
     },
     "event": {
-      "description": "The full event webhook payload. You can access individual properties of the event using this context. This object is identical to the webhook payload of the event that triggered the workflow run, and is different for each event. The webhooks for each GitHub Actions event is linked in [Event that trigger workflows](/articles/events-that-trigger-workflows/). For example, for a workflow run triggered by the [`push` event](https://docs.github.com/actions/using-workflows/events-that-trigger-workflows#push), this object contains the contents of the [push webhook payload](https://docs.github.com/developers/webhooks-and-events/webhooks/webhook-events-and-payloads#push)."
+      "description": "The full event webhook payload. You can access individual properties of the event using this context. This object is identical to the webhook payload of the event that triggered the workflow run, and is different for each event. The webhooks for each GitHub Actions event is linked in \"[Events that trigger workflows](https://docs.github.com/actions/using-workflows/events-that-trigger-workflows).\" For example, for a workflow run triggered by the [`push` event](https://docs.github.com/actions/using-workflows/events-that-trigger-workflows#push), this object contains the contents of the [push webhook payload](https://docs.github.com/webhooks-and-events/webhooks/webhook-events-and-payloads#push)."
     },
     "event_name": {
       "description": "The name of the event that triggered the workflow run."
@@ -90,53 +97,58 @@
       "description": "The path to the file on the runner that contains the full event webhook payload."
     },
     "graphql_url": {
-      "description": "The URL of the GitHub Actions GraphQL API."
+      "description": "The URL of the GitHub GraphQL API."
     },
     "head_ref": {
       "description": "The `head_ref` or source branch of the pull request in a workflow run. This property is only available when the event that triggers a workflow run is either `pull_request` or `pull_request_target`."
     },
     "job": {
-      "description": "The [`job_id`](/actions/reference/workflow-syntax-for-github-actions#jobsjob_id) of the current job. <br /> Note: This context property is set by the Actions runner, and is only available within the execution `steps` of a job. Otherwise, the value of this property will be `null`."
+      "description": "The [`job_id`](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_id) of the current job.\nNote: This context property is set by the Actions runner, and is only available within the execution `steps` of a job. Otherwise, the value of this property will be `null`."
     },
-    "ref": {
-      "description": "The fully-formed ref of the branch or tag that triggered the workflow run. For workflows triggered by `push`, this is the branch or tag ref that was pushed. For workflows triggered by `pull_request`, this is the pull request merge branch. For workflows triggered by `release`, this is the release tag created. For other triggers, this is the branch or tag ref that triggered the workflow run. This is only set if a branch or tag is available for the event type. The ref given is fully-formed, meaning that for branches the format is `refs/heads/<branch_name>`, for pull requests it is `refs/pull/<pr_number>/merge`, and for tags it is `refs/tags/<tag_name>`. For example, `refs/heads/feature-branch-1`.",
+    "job_workflow_sha": {
+      "description": "For jobs using a reusable workflow, the commit SHA for the reusable workflow file.",
       "versions": {
-        "ghes": "3.3",
-        "ghae": "3.3"
-      }
-    },
-    "ref_name": {
-      "description": "The short ref name of the branch or tag that triggered the workflow run. This value matches the branch or tag name shown on GitHub. For example, `feature-branch-1`.",
-      "versions": {
-        "ghes": "3.3",
-        "ghae": "3.3"
-      }
-    },
-    "ref_protected": {
-      "description": "`true` if branch protections are configured for the ref that triggered the workflow run.",
-      "versions": {
-        "ghes": "3.3",
-        "ghae": "3.3"
-      }
-    },
-    "ref_type": {
-      "description": "The type of ref that triggered the workflow run. Valid values are `branch` or `tag`.",
-      "versions": {
-        "ghes": "3.3",
-        "ghae": "3.3"
+        "ghes": ">=3.9",
+        "ghae": ">=3.9"
       }
     },
     "path": {
-      "description": "Path on the runner to the file that sets system `PATH` variables from workflow commands. This file is unique to the current step and is a different file for each step in a job. For more information, see [Workflow commands](https://docs.github.com/actions/learn-github-actions/workflow-commands-for-github-actions#adding-a-system-path)."
+      "description": "Path on the runner to the file that sets system PATH variables from workflow commands. This file is unique to the current step and is a different file for each step in a job. For more information, see \"[Workflow commands for GitHub Actions](https://docs.github.com/actions/using-workflows/workflow-commands-for-github-actions#adding-a-system-path).\""
+    },
+    "ref": {
+      "description": "The fully-formed ref of the branch or tag that triggered the workflow run. For workflows triggered by `push`, this is the branch or tag ref that was pushed. For workflows triggered by `pull_request`, this is the pull request merge branch. For workflows triggered by `release`, this is the release tag created. For other triggers, this is the branch or tag ref that triggered the workflow run. This is only set if a branch or tag is available for the event type. The ref given is fully-formed, meaning that for branches the format is `refs/heads/<branch_name>`, for pull requests it is `refs/pull/<pr_number>/merge`, and for tags it is `refs/tags/<tag_name>`. For example, `refs/heads/feature-branch-1`."
+    },
+    "ref_name": {
+      "description": "The short ref name of the branch or tag that triggered the workflow run. This value matches the branch or tag name shown on GitHub. For example, `feature-branch-1`."
+    },
+    "ref_protected": {
+      "description": "`true` if branch protections are configured for the ref that triggered the workflow run."
+    },
+    "ref_type": {
+      "description": "The type of ref that triggered the workflow run. Valid values are `branch` or `tag`."
     },
     "repository": {
-      "description": "The owner and repository name. For example, `Codertocat/Hello-World`."
+      "description": "The owner and repository name. For example, `octocat/Hello-World`."
+    },
+    "repository_id": {
+      "description": "The ID of the repository. For example, `123456789`. Note that this is different from the repository name.",
+      "versions": {
+        "ghes": ">=3.9",
+        "ghae": ">=3.9"
+      }
     },
     "repository_owner": {
-      "description": "The repository owner's name. For example, `Codertocat`."
+      "description": "The repository owner's username. For example, `octocat`."
+    },
+    "repository_owner_id": {
+      "description": "The repository owner's account ID. For example, `1234567`. Note that this is different from the owner's name.",
+      "versions": {
+        "ghes": ">=3.9",
+        "ghae": ">=3.9"
+      }
     },
     "repositoryUrl": {
-      "description": "The Git URL to the repository. For example, `git://github.com/codertocat/hello-world.git`."
+      "description": "The Git URL to the repository. For example, `git://github.com/octocat/hello-world.git`."
     },
     "retention_days": {
       "description": "The number of days that workflow run logs and artifacts are kept."
@@ -148,27 +160,19 @@
       "description": "A unique number for each run of a particular workflow in a repository. This number begins at 1 for the workflow's first run, and increments with each new run. This number does not change if you re-run the workflow run."
     },
     "run_attempt": {
-      "description": "A unique number for each attempt of a particular workflow run in a repository. This number begins at 1 for the workflow run's first attempt, and increments with each re-run.",
-      "versions": {
-        "ghes": "3.5",
-        "ghae": "3.4"
-      }
+      "description": "A unique number for each attempt of a particular workflow run in a repository. This number begins at 1 for the workflow run's first attempt, and increments with each re-run."
     },
     "secret_source": {
-      "description": "The source of a secret used in a workflow. Possible values are `None`, `Actions`, `Dependabot`, or `Codespaces`.",
-      "versions": {
-        "ghes": "3.3",
-        "ghae": "3.3"
-      }
+      "description": "The source of a secret used in a workflow. Possible values are `None`, `Actions`, `Dependabot`, or `Codespaces`."
     },
     "server_url": {
       "description": "The URL of the GitHub server. For example: `https://github.com`."
     },
     "sha": {
-      "description": "The commit SHA that triggered the workflow. The value of this commit SHA depends on the event that triggered the workflow. For more information, see [Events that trigger workflows.](https://docs.github.com/actions/using-workflows/events-that-trigger-workflows) For example, `ffac537e6cbbf934b08745a378932722df287a53`."
+      "description": "The commit SHA that triggered the workflow. The value of this commit SHA depends on the event that triggered the workflow. For more information, see \"[Events that trigger workflows](https://docs.github.com/actions/using-workflows/events-that-trigger-workflows).\" For example, `ffac537e6cbbf934b08745a378932722df287a53`."
     },
     "token": {
-      "description": "A token to authenticate on behalf of the GitHub App installed on your repository. This is functionally equivalent to the `GITHUB_TOKEN` secret. For more information, see [Automatic token authentication](https://docs.github.com/actions/security-guides/automatic-token-authentication).\nNote: This context property is set by the Actions runner, and is only available within the execution `steps` of a job. Otherwise, the value of this property will be `null`."
+      "description": "A token to authenticate on behalf of the GitHub App installed on your repository. This is functionally equivalent to the `GITHUB_TOKEN` secret. For more information, see \"[Automatic token authentication](https://docs.github.com/actions/security-guides/automatic-token-authentication).\"\nNote: This context property is set by the Actions runner, and is only available within the execution `steps` of a job. Otherwise, the value of this property will be `null`."
     },
     "triggering_actor": {
       "description": "The username of the user that initiated the workflow run. If the workflow run is a re-run, this value may differ from `github.actor`. Any workflow re-runs will use the privileges of `github.actor`, even if the actor initiating the re-run (`github.triggering_actor`) has different privileges."
@@ -176,13 +180,56 @@
     "workflow": {
       "description": "The name of the workflow. If the workflow file doesn't specify a `name`, the value of this property is the full path of the workflow file in the repository."
     },
+    "workflow_ref": {
+      "description": "The ref path to the workflow. For example, `octocat/hello-world/.github/workflows/my-workflow.yml@refs/heads/my_branch`.",
+      "versions": {
+        "ghes": ">=3.9",
+        "ghae": ">=3.9"
+      }
+    },
+    "workflow_sha": {
+      "description": "The commit SHA for the workflow file.",
+      "versions": {
+        "ghes": ">=3.9",
+        "ghae": ">=3.9"
+      }
+    },
     "workspace": {
       "description": "The default working directory on the runner for steps, and the default location of your repository when using the [`checkout`](https://github.com/actions/checkout) action."
     }
   },
+  "job": {
+    "container": {
+      "description": "Information about the job's container. For more information about containers, see \"[Running jobs in a container](https://docs.github.com/actions/using-jobs/running-jobs-in-a-container).\""
+    },
+    "container.id": {
+      "description": "The ID of the container."
+    },
+    "container.network": {
+      "description": "The ID of the container network. The runner creates the network used by all containers in a job."
+    },
+    "services": {
+      "description": "The service containers created for a job. For more information about service containers, see \"[Using service containers](https://docs.github.com/actions/using-containerized-services/about-service-containers).\""
+    },
+    "services.<service_id>.id": {
+      "description": "The ID of the service container."
+    },
+    "services.<service_id>.network": {
+      "description": "The ID of the service container network. The runner creates the network used by all containers in a job."
+    },
+    "services.<service_id>.ports": {
+      "description": "The exposed ports of the service container."
+    },
+    "status": {
+      "description": "The current status of the job. Possible values are `success`, `failure`, or `cancelled`."
+    },
+    "check_run_id": {
+      "description": "The unique identifier of the check run for this job."
+    }
+  },
   "secrets": {
     "GITHUB_TOKEN": {
-      "description": "`GITHUB_TOKEN` is a secret that is automatically created for every workflow run, and is always included in the secrets context. For more information, see [Automatic token authentication](https://docs.github.com/actions/security-guides/automatic-token-authentication)."
+      "description": "Automatically created token for each workflow run. For more information, see \"[Automatic token authentication](https://docs.github.com/actions/security-guides/automatic-token-authentication).\""
     }
   },
   "jobs": {
@@ -195,13 +242,13 @@
   },
   "steps": {
     "outputs": {
-      "description": "The set of outputs defined for the step."
+      "description": "The set of outputs defined for the step. For more information, see \"[Metadata syntax for GitHub Actions](https://docs.github.com/actions/creating-actions/metadata-syntax-for-github-actions#outputs-for-docker-container-and-javascript-actions).\""
     },
     "conclusion": {
-      "description": "The result of a completed step after `continue-on-error` is applied. Possible values are `success`, `failure`, `cancelled`, or `skipped`. When a `continue-on-error` step fails, the `outcome` is `failure`, but the final conclusion is `success`."
+      "description": "The result of a completed step after [`continue-on-error`](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepscontinue-on-error) is applied. Possible values are `success`, `failure`, `cancelled`, or `skipped`. When a `continue-on-error` step fails, the `outcome` is `failure`, but the final conclusion is `success`."
     },
     "outcome": {
-      "description": "The result of a completed step before `continue-on-error` is applied. Possible values are `success`, `failure`, `cancelled`, or `skipped`. When a `continue-on-error` step fails, the `outcome` is `failure`, but the final conclusion is `success`."
+      "description": "The result of a completed step before [`continue-on-error`](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepscontinue-on-error) is applied. Possible values are `success`, `failure`, `cancelled`, or `skipped`. When a `continue-on-error` step fails, the `outcome` is `failure`, but the final conclusion is `success`."
     }
   },
   "runner": {
@@ -218,24 +265,30 @@
       "description": "The path to a temporary directory on the runner. This directory is emptied at the beginning and end of each job. Note that files will not be removed if the runner's user account does not have permission to delete them."
     },
     "tool_cache": {
-      "description": "The path to the directory containing preinstalled tools for GitHub-hosted runners. For more information, see \"[About GitHub-hosted runners](https://docs.github.com/actions/reference/specifications-for-github-hosted-runners/#supported-software)\"."
+      "description": "The path to the directory containing preinstalled tools for GitHub-hosted runners. For more information, see \"[About GitHub-hosted runners](https://docs.github.com/actions/reference/specifications-for-github-hosted-runners/#supported-software).\""
     },
     "debug": {
-      "description": "This is set only if [debug logging](https://docs.github.com/actions/monitoring-and-troubleshooting-workflows/enabling-debug-logging) is enabled, and always has the value of 1. It can be useful as an indicator to enable additional debugging or verbose logging in your own job steps."
+      "description": "This is set only if [`ACTIONS_STEP_DEBUG`](https://docs.github.com/actions/monitoring-and-troubleshooting-workflows/enabling-debug-logging) is enabled, and always has the value of `\"1\"`. It can be useful as an indicator to enable additional debugging or verbose logging in your own job steps."
+    },
+    "environment": {
+      "description": "The environment of the runner executing the job. Possible values are `github-hosted` for GitHub-hosted runners, or `self-hosted` for self-hosted runners."
+    },
+    "workspace": {
+      "description": "The runner-specific working directory path for the job."
     }
   },
   "strategy": {
     "fail-fast": {
-      "description": "The `fail-fast` setting for the job. Possible values are `true` or `false`. For more information, see [Workflow syntax for GitHub Actions: `jobs.<job_id>.strategy.fail-fast`](https://docs.github.com/actions/reference/workflow-syntax-for-github-actions#jobsjob_idstrategyfail-fast)."
-    },
-    "max-parallel": {
-      "description": "The `max-parallel` setting for the job. For more information, see [Workflow syntax for GitHub Actions: `jobs.<job_id>.strategy.max-parallel`](https://docs.github.com/actions/reference/workflow-syntax-for-github-actions#jobsjob_idstrategymax-parallel)."
+      "description": "When `true`, all in-progress jobs are canceled if any job in a matrix fails. For more information, see \"[Workflow syntax for GitHub Actions](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstrategyfail-fast).\""
     },
     "job-index": {
       "description": "The index of the current job in the matrix. **Note:** This number is a zero-based number. The first job's index in the matrix is `0`."
     },
     "job-total": {
       "description": "The total number of jobs in the matrix. **Note:** This number **is not** a zero-based number. For example, for a matrix with four jobs, the value of `job-total` is `4`."
+    },
+    "max-parallel": {
+      "description": "The maximum number of jobs that can run simultaneously when using a matrix job strategy. For more information, see \"[Workflow syntax for GitHub Actions](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstrategymax-parallel).\""
     }
   }
 }

languageservice/src/context-providers/descriptions.ts

@@ -1,4 +1,4 @@
-import descriptions from "./descriptions.json" assert {type: "json"};
+import descriptions from "./descriptions.min.json";
 
 export const RootContext = "root";
 const FunctionContext = "functions";