Release extension version 0.3.21 (#226)

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

NEOVIM_SETUP.md

@@ -1,152 +0,0 @@
-# Using GitHub Actions Language Server in Neovim
-
-## Prerequisites
-
-- Node.js 18+
-- Neovim 0.11+ with the new LSP config format
-
-## Setup Options
-
-### Option 1: Install from npm (Recommended)
-
-Once published, you can install globally:
-
-```bash
-npm install -g @actions/languageserver
-```
-
-Then configure Neovim to use the installed binary:
-
-```lua
--- ~/.config/nvim/lsp/actionsls.lua
-return {
-  cmd = { "actions-languageserver" },
-  filetypes = { "yaml.ghaction" },  -- GitHub Actions workflow files only
-  root_markers = { ".git" },
-  init_options = {
-    sessionToken = vim.fn.system("gh auth token"):gsub("%s+", ""),
-    logLevel = "info",
-  },
-}
-```
-
-**Note:** This requires the package to be published to npm first.
-
-### Option 2: Local Development Build
-
-For development or if the npm package isn't published yet:
-
-### 1. Clone and build
-
-```bash
-git clone https://github.com/actions/languageservices.git
-cd languageservices
-npm install
-npm run build --workspaces --if-present
-```
-
-### 2. Bundle the server
-
-The server needs to be bundled into a single file to avoid ESM module resolution issues:
-
-```bash
-cd languageserver
-npx esbuild src/index.ts \
-  --bundle \
-  --platform=node \
-  --target=node18 \
-  --format=cjs \
-  --outfile=dist/server-bundled.cjs \
-  --external:vscode \
-  --loader:.json=json
-```
-
-This creates `dist/server-bundled.cjs` (~5.6MB) that contains the entire server.
-
-### 3. Configure Neovim
-
-Create `~/.config/nvim/lsp/actionsls.lua`:
-
-```lua
-return {
-  cmd = {
-    "/absolute/path/to/languageservices/languageserver/bin/actions-languageserver",
-  },
-  filetypes = { "yaml.ghaction" },  -- GitHub Actions workflow files only
-  root_markers = { ".git" },
-  init_options = {
-    sessionToken = vim.fn.system("gh auth token"):gsub("%s+", ""),
-    logLevel = "info",
-  },
-}
-```
-
-**Important:** Replace `/absolute/path/to/languageservices` with your actual clone path.
-
-## Filetype Detection for GitHub Actions Workflows
-
-To ensure the LSP only runs on GitHub Actions workflow files (not all YAML files), set up filetype detection:
-
-**Option A:** In `~/.config/nvim/init.lua`:
-
-```lua
-vim.api.nvim_create_autocmd({"BufRead", "BufNewFile"}, {
-  pattern = ".github/workflows/*.{yml,yaml}",
-  callback = function()
-    vim.bo.filetype = "yaml.ghaction"
-  end,
-})
-```
-
-**Option B:** Create `~/.config/nvim/ftdetect/ghaction.vim`:
-
-```vim
-au BufRead,BufNewFile .github/workflows/*.yml,*.yaml setfiletype yaml.ghaction
-```
-
-This sets the filetype to `yaml.ghaction` for files in `.github/workflows/`, matching the `filetypes` setting in your LSP config.
-
-### 4. Enable the LSP in your init.lua
-
-Add to your Neovim configuration:
-
-```lua
-vim.lsp.enable('actionsls')
-```
-
-### 5. Restart Neovim
-
-Open any `.github/workflows/*.yml` file. The filetype detection will set it to `yaml.ghaction`, and the language server will attach automatically.
-
-## Files Created
-
-- `languageserver/dist/server-bundled.cjs` - Bundled server (~5.6MB)
-- `languageserver/bin/actions-languageserver` - Shell wrapper script
-
-The `dist/` directory is gitignored; you'll need to rebuild after pulling updates.
-
-## Troubleshooting
-
-Check if the server is running:
-
-```vim
-:lua =vim.lsp.get_clients()
-```
-
-View LSP logs:
-
-```bash
-tail -f ~/.local/state/nvim/lsp.log
-```
-
-Manually start the server to test:
-
-```vim
-:lua vim.lsp.start({name='actionsls', cmd={'/path/to/bin/actions-languageserver'}, root_dir=vim.fn.getcwd(), init_options={sessionToken='', logLevel='info'}})
-```
-
-## Notes
-
-- The main code change is in `languageserver/src/index.ts` to use dynamic imports, avoiding loading browser modules in Node.js
-- The bundling step is necessary because TypeScript outputs ESM with bare imports that Node.js can't resolve
-- Only workflow files in git repositories will activate the LSP (due to `root_markers = { ".git" }`)

expressions/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@actions/expressions",
-  "version": "0.3.20",
+  "version": "0.3.21",
   "license": "MIT",
   "type": "module",
   "source": "./src/index.ts",

languageserver/bin/actions-languageserver

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

languageserver/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@actions/languageserver",
-  "version": "0.3.20",
+  "version": "0.3.21",
   "description": "Language server for GitHub Actions",
   "license": "MIT",
   "type": "module",
@@ -32,7 +32,6 @@
   },
   "scripts": {
     "build": "tsc --build tsconfig.build.json",
-    "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'",
@@ -43,12 +42,9 @@
     "test-watch": "NODE_OPTIONS=\"--experimental-vm-modules\" jest --watch",
     "watch": "tsc --build tsconfig.build.json --watch"
   },
-  "bin": {
-    "actions-languageserver": "./bin/actions-languageserver"
-  },
   "dependencies": {
-    "@actions/languageservice": "^0.3.20",
-    "@actions/workflow-parser": "^0.3.20",
+    "@actions/languageservice": "^0.3.21",
+    "@actions/workflow-parser": "^0.3.21",
     "@octokit/rest": "^21.1.1",
     "@octokit/types": "^9.0.0",
     "vscode-languageserver": "^8.0.2",
@@ -65,7 +61,6 @@
     "@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/script/esbuild

@@ -1,10 +0,0 @@
-#!/bin/bash
-
-npx esbuild src/index.ts \
-  --bundle \
-  --platform=node \
-  --target=node18 \
-  --format=cjs \
-  --outfile=dist/server-bundled.cjs \
-  --external:vscode \
-  --loader:.json=json

languageserver/src/connection.ts

@@ -1,11 +1,8 @@
-import {documentLinks, getCodeActions, hover, validate, ValidationConfig} from "@actions/languageservice";
+import {documentLinks, 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";
 import {
-  CodeAction,
-  CodeActionKind,
-  CodeActionParams,
   CompletionItem,
   Connection,
   DocumentLink,
@@ -75,9 +72,6 @@ export function initConnection(connection: Connection) {
         hoverProvider: true,
         documentLinkProvider: {
           resolveProvider: false
-        },
-        codeActionProvider: {
-          codeActionKinds: [CodeActionKind.QuickFix]
         }
       }
     };
@@ -164,16 +158,6 @@ export function initConnection(connection: Connection) {
     return documentLinks(getDocument(documents, textDocument), repoContext?.workspaceUri);
   });
 
-  connection.onCodeAction(async (params: CodeActionParams): Promise<CodeAction[]> => {
-    return timeOperation("codeAction", async () => {
-      return getCodeActions({
-        uri: params.textDocument.uri,
-        diagnostics: params.context.diagnostics,
-        only: params.context.only
-      });
-    });
-  });
-
   // Make the text document manager listen on the connection
   // for open, change and close text document events
   documents.listen(connection);

languageserver/src/index.ts

@@ -1,12 +1,12 @@
-import { Connection } from "vscode-languageserver";
+import {Connection} from "vscode-languageserver";
 import {
   BrowserMessageReader,
   BrowserMessageWriter,
   createConnection as createBrowserConnection
 } from "vscode-languageserver/browser";
-import { createConnection as createNodeConnection } from "vscode-languageserver/node";
+import {createConnection as createNodeConnection} from "vscode-languageserver/node";
 
-import { initConnection } from "./connection";
+import {initConnection} from "./connection";
 
 /** Helper function determining whether we are executing with node runtime */
 function isNode(): boolean {

languageservice/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@actions/languageservice",
-  "version": "0.3.20",
+  "version": "0.3.21",
   "description": "Language service for GitHub Actions",
   "license": "MIT",
   "type": "module",
@@ -44,8 +44,8 @@
     "watch": "tsc --build tsconfig.build.json --watch"
   },
   "dependencies": {
-    "@actions/expressions": "^0.3.20",
-    "@actions/workflow-parser": "^0.3.20",
+    "@actions/expressions": "^0.3.21",
+    "@actions/workflow-parser": "^0.3.21",
     "vscode-languageserver-textdocument": "^1.0.7",
     "vscode-languageserver-types": "^3.17.2",
     "vscode-uri": "^3.0.8",

languageservice/src/code-actions/index.ts

@@ -1,54 +0,0 @@
-import {CodeAction, CodeActionKind, Diagnostic} from "vscode-languageserver-types";
-import {CodeActionContext, CodeActionProvider} from "./types";
-import {quickfixProviders} from "./quickfix";
-
-// Aggregate all providers by kind
-const providersByKind: Map<string, CodeActionProvider[]> = new Map([
-  [CodeActionKind.QuickFix, quickfixProviders]
-  // [CodeActionKind. Refactor, refactorProviders],
-  // [CodeActionKind.Source, sourceProviders],
-  // etc
-]);
-
-export interface CodeActionConfig {
-  // TODO: actionsMetadataProvider, fileProvider, etc.
-}
-
-export interface CodeActionParams {
-  uri: string;
-  diagnostics: Diagnostic[];
-  only?: string[];
-}
-
-export function getCodeActions(params: CodeActionParams, config?: CodeActionConfig): CodeAction[] {
-  const actions: CodeAction[] = [];
-  const context: CodeActionContext = {
-    uri: params.uri
-  };
-
-  // Filter to requested kinds, or use all if none specified
-  const requestedKinds = params.only;
-  const kindsToCheck = requestedKinds
-    ? [...providersByKind.keys()].filter(kind => requestedKinds.some(requested => kind.startsWith(requested)))
-    : [...providersByKind.keys()];
-
-  for (const diagnostic of params.diagnostics) {
-    for (const kind of kindsToCheck) {
-      const providers = providersByKind.get(kind) ?? [];
-      for (const provider of providers) {
-        if (provider.diagnosticCodes.includes(diagnostic.code)) {
-          const action = provider.createCodeAction(context, diagnostic);
-          if (action) {
-            action.kind = kind;
-            action.diagnostics = [diagnostic];
-            actions.push(action);
-          }
-        }
-      }
-    }
-  }
-
-  return actions;
-}
-
-export type {CodeActionContext, CodeActionProvider} from "./types";

languageservice/src/code-actions/quickfix/add-missing-inputs.ts

@@ -1,67 +0,0 @@
-import { CodeAction, TextEdit } from "vscode-languageserver-types";
-import { CodeActionContext, CodeActionProvider } from "../types";
-import { DiagnosticCode, MissingInputsDiagnosticData } from "../../validate-action";
-
-export const addMissingInputsProvider: CodeActionProvider = {
-  diagnosticCodes: [DiagnosticCode.MissingRequiredInputs],
-
-  createCodeAction(context, diagnostic): CodeAction | undefined {
-    const data = diagnostic.data as MissingInputsDiagnosticData | undefined;
-    if (!data) {
-      return undefined;
-    }
-
-    const edits = createInputEdits(data);
-    if (!edits) {
-      return undefined;
-    }
-
-    const inputNames = data.missingInputs.map(i => i.name).join(", ");
-
-    return {
-      title: `Add missing input${data.missingInputs.length > 1 ? "s" : ""}: ${inputNames}`,
-      edit: {
-        changes: {
-          [context.uri]: edits,
-        },
-      },
-    };
-  },
-};
-
-function createInputEdits(data: MissingInputsDiagnosticData): TextEdit[] | undefined {
-  const edits: TextEdit[] = [];
-
-  if (data.hasWithKey && data.withIndent !== undefined) {
-    // `with:` exists - use its indentation + 2 for inputs
-    const inputIndent = " ".repeat(data.withIndent + 2);
-
-    const inputLines = data.missingInputs.map(input => {
-      const value = input.default !== undefined ? input.default : '""';
-      return `${inputIndent}${input.name}: ${value}`;
-    });
-
-    edits.push({
-      range: { start: data.insertPosition, end: data.insertPosition },
-      newText: inputLines.map(line => line + "\n").join(""),
-    });
-  } else {
-    // No `with:` key - `with:` at step indentation, inputs at step indentation + 2
-    const withIndent = " ".repeat(data.stepIndent);
-    const inputIndent = " ".repeat(data.stepIndent + 2);
-
-    const inputLines = data.missingInputs.map(input => {
-      const value = input.default !== undefined ? input.default : '""';
-      return `${inputIndent}${input.name}: ${value}`;
-    });
-
-    const newText = [`${withIndent}with:\n`, ...inputLines.map(line => `${line}\n`)].join("");
-
-    edits.push({
-      range: { start: data.insertPosition, end: data.insertPosition },
-      newText,
-    });
-  }
-
-  return edits;
-}

languageservice/src/code-actions/quickfix/index.ts

@@ -1,4 +0,0 @@
-import {CodeActionProvider} from "../types";
-import {addMissingInputsProvider} from "./add-missing-inputs";
-
-export const quickfixProviders: CodeActionProvider[] = [addMissingInputsProvider];

languageservice/src/code-actions/tests/runner.test.ts

@@ -1,90 +0,0 @@
-import * as path from "path";
-import {fileURLToPath} from "url";
-import {loadTestCases, runTestCase} from "./runner";
-import {ValidationConfig} from "../../validate";
-import {ActionMetadata, ActionReference} from "../../action";
-import {clearCache} from "../../utils/workflow-cache";
-
-// ESM-compatible __dirname
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = path.dirname(__filename);
-
-// Mock action metadata provider for tests
-const validationConfig: ValidationConfig = {
-  actionsMetadataProvider: {
-    fetchActionMetadata: (ref: ActionReference): Promise<ActionMetadata | undefined> => {
-      const key = `${ref.owner}/${ref.name}@${ref.ref}`;
-
-      const metadata: Record<string, ActionMetadata> = {
-        "actions/cache@v1": {
-          name: "Cache",
-          description: "Cache dependencies",
-          inputs: {
-            path: {
-              description: "A list of files to cache",
-              required: true
-            },
-            key: {
-              description: "Cache key",
-              required: true
-            },
-            "restore-keys": {
-              description: "Restore keys",
-              required: false
-            }
-          }
-        },
-        "actions/setup-node@v3": {
-          name: "Setup Node",
-          description: "Setup Node. js",
-          inputs: {
-            "node-version": {
-              description: "Node version",
-              required: true,
-              default: "16"
-            }
-          }
-        }
-      };
-
-      return Promise.resolve(metadata[key]);
-    }
-  }
-};
-
-// Point to the source testdata directory
-const testdataDir = path.join(__dirname, "testdata");
-
-beforeEach(() => {
-  clearCache();
-});
-
-describe("code action golden tests", () => {
-  const testCases = loadTestCases(testdataDir);
-
-  if (testCases.length === 0) {
-    it.todo("no test cases found - add . yml files to testdata/");
-    return;
-  }
-
-  for (const testCase of testCases) {
-    it(testCase.name, async () => {
-      const result = await runTestCase(testCase, validationConfig);
-
-      if (!result.passed) {
-        let errorMessage = result.error || "Test failed";
-
-        if (result.expected !== undefined && result.actual !== undefined) {
-          errorMessage += "\n\n";
-          errorMessage += "=== EXPECTED (golden file) ===\n";
-          errorMessage += result.expected;
-          errorMessage += "\n\n";
-          errorMessage += "=== ACTUAL ===\n";
-          errorMessage += result.actual;
-        }
-
-        throw new Error(errorMessage);
-      }
-    });
-  }
-});

languageservice/src/code-actions/tests/runner.ts

@@ -1,227 +0,0 @@
-import * as fs from "fs";
-import * as path from "path";
-import { TextEdit } from "vscode-languageserver-types";
-import { TextDocument } from "vscode-languageserver-textdocument";
-import { validate, ValidationConfig } from "../../validate";
-import { getCodeActions, CodeActionParams } from "../index";
-
-// Marker pattern: # want "diagnostic message" fix="code-action-name"
-const MARKER_PATTERN = /#\s*want\s+"([^"]+)"(?:\s+fix="([^"]+)")?/;
-
-export interface TestCase {
-  name: string;
-  inputPath: string;
-  goldenPath: string;
-  input: string;
-  golden: string;
-  markers: Marker[];
-}
-
-export interface Marker {
-  line: number;
-  message: string;
-  fix?: string;
-}
-
-export interface TestResult {
-  name: string;
-  passed: boolean;
-  error?: string;
-  expected?: string;
-  actual?: string;
-}
-
-/**
- * Parse markers from input file content
- */
-export function parseMarkers(content: string): Marker[] {
-  const lines = content.split("\n");
-  const markers: Marker[] = [];
-
-  for (let i = 0; i < lines.length; i++) {
-    const match = lines[i].match(MARKER_PATTERN);
-    if (match) {
-      markers.push({
-        line: i,
-        message: match[1],
-        fix: match[2]
-      });
-    }
-  }
-
-  return markers;
-}
-
-/**
- * Strip markers from content (for processing)
- */
-export function stripMarkers(content: string): string {
-  return content
-    .split("\n")
-    .map(line => line.replace(MARKER_PATTERN, "").trimEnd())
-    .join("\n");
-}
-
-/**
- * Load all test cases from a testdata directory
- */
-export function loadTestCases(testdataDir: string): TestCase[] {
-  const testCases: TestCase[] = [];
-
-  function walkDir(dir: string) {
-    const entries = fs.readdirSync(dir, { withFileTypes: true });
-
-    for (const entry of entries) {
-      const fullPath = path.join(dir, entry.name);
-
-      if (entry.isDirectory()) {
-        walkDir(fullPath);
-      } else if (entry.isFile() && entry.name.endsWith(".yml") && !entry.name.endsWith(". golden.yml")) {
-        const goldenPath = fullPath.replace(".yml", ".golden.yml");
-
-        if (fs.existsSync(goldenPath)) {
-          const input = fs.readFileSync(fullPath, "utf-8");
-          const golden = fs.readFileSync(goldenPath, "utf-8");
-
-          testCases.push({
-            name: path.relative(testdataDir, fullPath),
-            inputPath: fullPath,
-            goldenPath,
-            input,
-            golden,
-            markers: parseMarkers(input)
-          });
-        }
-      }
-    }
-  }
-
-  walkDir(testdataDir);
-  return testCases;
-}
-
-/**
- * Apply text edits to a document
- */
-export function applyEdits(content: string, edits: TextEdit[]): string {
-  // Sort edits in reverse order by position to apply from bottom to top
-  const sortedEdits = [...edits].sort((a, b) => {
-    if (b.range.start.line !== a.range.start.line) {
-      return b.range.start.line - a.range.start.line;
-    }
-    return b.range.start.character - a.range.start.character;
-  });
-
-  const lines = content.split("\n");
-
-  for (const edit of sortedEdits) {
-    const startLine = edit.range.start.line;
-    const startChar = edit.range.start.character;
-    const endLine = edit.range.end.line;
-    const endChar = edit.range.end.character;
-
-    const before = lines[startLine].slice(0, startChar);
-    const after = lines[endLine].slice(endChar);
-
-    const newLines = edit.newText.split("\n");
-    newLines[0] = before + newLines[0];
-    newLines[newLines.length - 1] = newLines[newLines.length - 1] + after;
-
-    lines.splice(startLine, endLine - startLine + 1, ...newLines);
-  }
-
-  return lines.join("\n");
-}
-
-/**
- * Run a single test case
- */
-export async function runTestCase(testCase: TestCase, validationConfig: ValidationConfig): Promise<TestResult> {
-  const strippedInput = stripMarkers(testCase.input);
-  const document = TextDocument.create("file:///test.yml", "yaml", 1, strippedInput);
-
-  // 1. Validate and get diagnostics
-  const diagnostics = await validate(document, validationConfig);
-
-  // 2.  Verify all expected diagnostics are present
-  const missingDiagnostics: string[] = [];
-  for (const marker of testCase.markers) {
-    const found = diagnostics.find(d => d.range.start.line === marker.line && d.message.includes(marker.message));
-    console.log(found);
-    if (!found) {
-      missingDiagnostics.push(`line ${marker.line}: "${marker.message}"`);
-    }
-  }
-
-  if (missingDiagnostics.length > 0) {
-    return {
-      name: testCase.name,
-      passed: false,
-      error: `Missing expected diagnostics:\n  ${missingDiagnostics.join(
-        "\n  "
-      )}\n\nActual diagnostics:\n  ${diagnostics.map(d => `line ${d.range.start.line}: "${d.message}"`).join("\n  ")}`
-    };
-  }
-
-  // 3.  Collect all edits from all matching code actions
-  const allEdits: TextEdit[] = [];
-
-  for (const marker of testCase.markers) {
-    if (!marker.fix) {
-      continue;
-    }
-
-    const diagnostic = diagnostics.find(d => d.range.start.line === marker.line && d.message.includes(marker.message));
-
-    if (!diagnostic) {
-      continue; // Already reported above
-    }
-
-    const params: CodeActionParams = {
-      uri: document.uri,
-      diagnostics: [diagnostic]
-    };
-
-    const actions = getCodeActions(params);
-    const matchingAction = actions.find(a => a.title.toLowerCase().includes(marker.fix!.toLowerCase()));
-
-    if (!matchingAction) {
-      return {
-        name: testCase.name,
-        passed: false,
-        error: `Code action "${marker.fix}" not found for diagnostic on line ${marker.line}.\nAvailable actions: ${actions.map(a => a.title).join(", ") || "(none)"
-          }`
-      };
-    }
-
-    if (!matchingAction.edit?.changes) {
-      return {
-        name: testCase.name,
-        passed: false,
-        error: `Code action "${marker.fix}" has no edits`
-      };
-    }
-
-    const edits = matchingAction.edit.changes[document.uri] || [];
-    allEdits.push(...edits);
-  }
-
-  // 4. Apply all edits and compare to golden file
-  const actualOutput = applyEdits(strippedInput, allEdits);
-  const expectedOutput = testCase.golden;
-
-  if (actualOutput.trim() !== expectedOutput.trim()) {
-    return {
-      name: testCase.name,
-      passed: false,
-      error: "Output does not match golden file",
-      expected: expectedOutput,
-      actual: actualOutput
-    };
-  }
-
-  return {
-    name: testCase.name,
-    passed: true
-  };
-}

languageservice/src/code-actions/tests/testdata/quickfix/existing-with-key-without-inputs.golden.yml

@@ -1,9 +0,0 @@
-on: push
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/cache@v1
-        with:
-          path: ""
-          key: ""

languageservice/src/code-actions/tests/testdata/quickfix/existing-with-key-without-inputs.yml

@@ -1,7 +0,0 @@
-on: push
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/cache@v1
-        with: # want "Missing required inputs: `path`, `key`" fix="Add missing inputs: path, key"

languageservice/src/code-actions/tests/testdata/quickfix/existing-with-key.golden.yml

@@ -1,10 +0,0 @@
-on: push
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/cache@v1
-        with:
-          restore-keys: ${{ runner.os }}-
-          path: ""
-          key: ""

languageservice/src/code-actions/tests/testdata/quickfix/existing-with-key.yml

@@ -1,8 +0,0 @@
-on: push
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/cache@v1
-        with: # want "Missing required inputs: `path`, `key`" fix="Add missing inputs: path, key"
-          restore-keys: ${{ runner.os }}-

languageservice/src/code-actions/tests/testdata/quickfix/no-with-key.golden.yml

@@ -1,9 +0,0 @@
-on: push
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/cache@v1
-        with:
-          path: ""
-          key: ""

languageservice/src/code-actions/tests/testdata/quickfix/no-with-key.yml

@@ -1,6 +0,0 @@
-on: push
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/cache@v1 # want "Missing required inputs: `path`, `key`" fix="Add missing inputs: path, key"

languageservice/src/code-actions/types.ts

@@ -1,21 +0,0 @@
-import {CodeAction, Diagnostic} from "vscode-languageserver-types";
-
-export interface CodeActionContext {
-  uri: string;
-  // TODO: add things like workflow template, parsed content, etc.
-}
-
-/**
- * A provider that can produce a code action for a given diagnostic
- */
-export interface CodeActionProvider {
-  /**
-   * The diagnostic codes this provider handles
-   */
-  diagnosticCodes: (string | number | undefined)[];
-
-  /**
-   * Create a code action for the diagnostic, if applicable
-   */
-  createCodeAction(context: CodeActionContext, diagnostic: Diagnostic): CodeAction | undefined;
-}

languageservice/src/complete.expressions.test.ts

@@ -1268,7 +1268,7 @@ 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.reusable-workflows.test.ts

@@ -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/context-providers/needs.test.ts

@@ -111,7 +111,7 @@ jobs:
 on: push
 jobs:
   a:
-    uses: ./reusable-workflow-with-outputs.yaml
+    uses: ./.github/workflows/reusable-workflow-with-outputs.yaml
 
   b:
     needs: [a]

languageservice/src/hover.reusable-workflow.test.ts

@@ -14,7 +14,7 @@ on: push
 
 jobs:
   build:
-    uses: ./reusable-workflow-with-inputs.yaml
+    uses: ./.github/workflows/reusable-workflow-with-inputs.yaml
     with:
       us|ername:
 `;
@@ -31,7 +31,7 @@ on: push
 
 jobs:
   build:
-    uses: ./reusable-workflow-with-inputs-no-description.yaml
+    uses: ./.github/workflows/reusable-workflow-with-inputs-no-description.yaml
     with:
       us|ername:
 `;
@@ -48,7 +48,7 @@ on: push
 
 jobs:
   build:
-    uses: ./reusable-workflow-with-outputs.yaml
+    uses: ./.github/workflows/reusable-workflow-with-outputs.yaml
   echo_outputs:
     runs-on: ubuntu-latest
     needs: build

languageservice/src/hover.test.ts

@@ -110,11 +110,8 @@ jobs:
 `;
     const result = await hover(...getPositionFromCursor(input));
     expect(result).not.toBeUndefined();
-    expect(result?.contents).toEqual(
-      "Runs at 0 and 30 minutes past the hour, at 00:00 and 12:00\n\n" +
-        "Actions schedules run at most every 5 minutes. " +
-        "[Learn more](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#onschedule)"
-    );
+    // Cron description is now shown via diagnostics, not hover
+    expect(result?.contents).toEqual("");
   });
 
   it("on a cron mapping key", async () => {

languageservice/src/hover.ts

@@ -2,11 +2,9 @@ import {data, DescriptionDictionary, Parser} from "@actions/expressions";
 import {FunctionDefinition, FunctionInfo} from "@actions/expressions/funcs/info";
 import {Lexer} from "@actions/expressions/lexer";
 import {ErrorPolicy} from "@actions/workflow-parser/model/convert";
-import {getCronDescription} from "@actions/workflow-parser/model/converter/cron";
 import {splitAllowedContext} from "@actions/workflow-parser/templates/allowed-context";
-import {StringToken} from "@actions/workflow-parser/templates/tokens/string-token";
 import {TemplateToken} from "@actions/workflow-parser/templates/tokens/template-token";
-import {isBasicExpression, isString} from "@actions/workflow-parser/templates/tokens/type-guards";
+import {isBasicExpression} from "@actions/workflow-parser/templates/tokens/type-guards";
 import {File} from "@actions/workflow-parser/workflows/file";
 import {FileProvider} from "@actions/workflow-parser/workflows/file-provider";
 import {Position, TextDocument} from "vscode-languageserver-textdocument";
@@ -23,7 +21,7 @@ import {ExpressionPos, mapToExpressionPos} from "./expression-hover/expression-p
 import {HoverVisitor} from "./expression-hover/visitor";
 import {info} from "./log";
 import {isPotentiallyExpression} from "./utils/expression-detection";
-import {findToken, TokenResult} from "./utils/find-token";
+import {findToken} from "./utils/find-token";
 import {mapRange} from "./utils/range";
 import {fetchOrConvertWorkflowTemplate, fetchOrParseWorkflow} from "./utils/workflow-cache";
 
@@ -89,17 +87,6 @@ export async function hover(document: TextDocument, position: Position, config?:
 
   info(`Calculating hover for token with definition ${token.definition.key}`);
 
-  if (tokenResult.parent && isCronMappingValue(tokenResult)) {
-    const tokenValue = (token as StringToken).value;
-    const description = getCronDescription(tokenValue);
-    if (description) {
-      return {
-        contents: description,
-        range: mapRange(token.range)
-      } satisfies Hover;
-    }
-  }
-
   if (tokenResult.parent && isReusableWorkflowJobInput(tokenResult)) {
     let description = getReusableWorkflowInputDescription(workflowContext, tokenResult);
     description = appendContext(description, token.definitionInfo?.allowedContext);
@@ -156,15 +143,6 @@ async function getDescription(
   return description || defaultDescription;
 }
 
-function isCronMappingValue(tokenResult: TokenResult): boolean {
-  return (
-    tokenResult.parent?.definition?.key === "cron-mapping" &&
-    !!tokenResult.token &&
-    isString(tokenResult.token) &&
-    tokenResult.token.value !== "cron"
-  );
-}
-
 function expressionHover(
   exprPos: ExpressionPos,
   context: DescriptionDictionary,

languageservice/src/index.ts

@@ -5,4 +5,3 @@ export {hover} from "./hover";
 export {Logger, LogLevel, registerLogger, setLogLevel} from "./log";
 export {validate, ValidationConfig, ActionsMetadataProvider} from "./validate";
 export {ValueProviderConfig, ValueProviderKind} from "./value-providers/config";
-export {getCodeActions} from "./code-actions";

languageservice/src/test-utils/test-file-provider.ts

@@ -5,9 +5,9 @@ export const testFileProvider: FileProvider = {
   // eslint-disable-next-line @typescript-eslint/require-await
   getFileContent: async ref => {
     switch (fileIdentifier(ref)) {
-      case "monalisa/octocat/workflow.yaml@main":
+      case "monalisa/octocat/.github/workflows/workflow.yaml@main":
         return {
-          name: "monalisa/octocat/workflow.yaml",
+          name: "monalisa/octocat/.github/workflows/workflow.yaml",
           content: `
 on: workflow_call
 jobs:
@@ -31,9 +31,9 @@ jobs:
 `
         };
 
-      case "./reusable-workflow.yaml":
+      case "./.github/workflows/reusable-workflow.yaml":
         return {
-          name: "reusable-workflow.yaml",
+          name: ".github/workflows/reusable-workflow.yaml",
           content: `
 on: workflow_call
 jobs:
@@ -44,9 +44,9 @@ jobs:
 `
         };
 
-      case "./reusable-workflow-with-inputs.yaml":
+      case "./.github/workflows/reusable-workflow-with-inputs.yaml":
         return {
-          name: "reusable-workflow-with-inputs.yaml",
+          name: ".github/workflows/reusable-workflow-with-inputs.yaml",
           content: `
 on:
   workflow_call:
@@ -76,9 +76,9 @@ jobs:
   `
         };
 
-      case "./reusable-workflow-with-inputs-no-description.yaml":
+      case "./.github/workflows/reusable-workflow-with-inputs-no-description.yaml":
         return {
-          name: "reusable-workflow-with-inputs.yaml",
+          name: ".github/workflows/reusable-workflow-with-inputs.yaml",
           content: `
 on:
   workflow_call:
@@ -95,9 +95,9 @@ jobs:
   `
         };
 
-      case "./reusable-workflow-with-outputs.yaml":
+      case "./.github/workflows/reusable-workflow-with-outputs.yaml":
         return {
-          name: "reusable-workflow-with-outputs.yaml",
+          name: ".github/workflows/reusable-workflow-with-outputs.yaml",
           content: `
 on:
   workflow_call:

languageservice/src/validate-action.ts

@@ -1,30 +1,12 @@
-import { isMapping } from "@actions/workflow-parser";
-import { isActionStep } from "@actions/workflow-parser/model/type-guards";
-import { Step } from "@actions/workflow-parser/model/workflow-template";
-import { ScalarToken } from "@actions/workflow-parser/templates/tokens/scalar-token";
-import { TemplateToken } from "@actions/workflow-parser/templates/tokens/template-token";
-import { Diagnostic, DiagnosticSeverity } from "vscode-languageserver-types";
-import { ActionReference, parseActionReference } from "./action";
-import { mapRange } from "./utils/range";
-import { ValidationConfig } from "./validate";
-
-export const DiagnosticCode = {
-  MissingRequiredInputs: "missing-required-inputs"
-} as const;
-
-export interface MissingInputsDiagnosticData {
-  action: ActionReference;
-  missingInputs: Array<{
-    name: string;
-    default?: string;
-  }>;
-  hasWithKey: boolean;
-  // Indentation of the `with:` key if present, or the step's base indentation
-  withIndent?: number;
-  stepIndent: number;
-  // Position where new content should be inserted
-  insertPosition: { line: number; character: number };
-}
+import {isMapping} from "@actions/workflow-parser";
+import {isActionStep} from "@actions/workflow-parser/model/type-guards";
+import {Step} from "@actions/workflow-parser/model/workflow-template";
+import {ScalarToken} from "@actions/workflow-parser/templates/tokens/scalar-token";
+import {TemplateToken} from "@actions/workflow-parser/templates/tokens/template-token";
+import {Diagnostic, DiagnosticSeverity} from "vscode-languageserver-types";
+import {parseActionReference} from "./action";
+import {mapRange} from "./utils/range";
+import {ValidationConfig} from "./validate";
 
 export async function validateAction(
   diagnostics: Diagnostic[],
@@ -53,7 +35,7 @@ export async function validateAction(
 
   let withKey: ScalarToken | undefined;
   let withToken: TemplateToken | undefined;
-  for (const { key, value } of stepToken) {
+  for (const {key, value} of stepToken) {
     if (key.toString() === "with") {
       withKey = key;
       withToken = value;
@@ -63,7 +45,7 @@ export async function validateAction(
 
   const stepInputs = new Map<string, ScalarToken>();
   if (withToken && isMapping(withToken)) {
-    for (const { key } of withToken) {
+    for (const {key} of withToken) {
       stepInputs.set(key.toString(), key);
     }
   }
@@ -101,47 +83,10 @@ export async function validateAction(
       missingRequiredInputs.length === 1
         ? `Missing required input \`${missingRequiredInputs[0][0]}\``
         : `Missing required inputs: ${missingRequiredInputs.map(input => `\`${input[0]}\``).join(", ")}`;
-
-    const stepIndent = stepToken.range ? stepToken.range.start.column - 1 : 0; // 0-indexed
-    const withIndent = withKey?.range ? withKey.range.start.column - 1 : undefined;
-
-    // Calculate insert position
-    // For withToken, we need to handle empty mappings specially - insert after the with: line
-    let insertPosition: { line: number; character: number };
-    if (withToken?.range) {
-      // Check if with: has any children by comparing start and end lines
-      const hasChildren = stepInputs.size > 0;
-      if (hasChildren) {
-        // Insert after the last child
-        insertPosition = { line: withToken.range.end.line - 1, character: 0 };
-      } else {
-        // Empty with: block - insert on the next line after with:
-        insertPosition = { line: withKey!.range!.end.line, character: 0 };
-      }
-    } else if (stepToken.range) {
-      insertPosition = { line: stepToken.range.end.line - 1, character: 0 };
-    } else {
-      insertPosition = { line: 0, character: 0 };
-    }
-
-    const diagnosticData: MissingInputsDiagnosticData = {
-      action,
-      missingInputs: missingRequiredInputs.map(([name, input]) => ({
-        name,
-        default: input.default
-      })),
-      hasWithKey: withKey !== undefined,
-      withIndent,
-      stepIndent,
-      insertPosition
-    };
-
     diagnostics.push({
       severity: DiagnosticSeverity.Error,
       range: mapRange((withKey || stepToken).range), // Highlight the whole step if we don't have a with key
-      message: message,
-      code: DiagnosticCode.MissingRequiredInputs,
-      data: diagnosticData
+      message: message
     });
   }
 }

languageservice/src/validate.actions.test.ts

@@ -249,28 +249,7 @@ jobs:
             line: 7
           }
         },
-        severity: DiagnosticSeverity.Error,
-        code: "missing-required-inputs",
-        data: {
-          action: {
-            name: "cache",
-            owner: "actions",
-            ref: "v1"
-          },
-          hasWithKey: true,
-          insertPosition: {
-            character: 0,
-            line: 9
-          },
-          missingInputs: [
-            {
-              default: undefined,
-              name: "path"
-            }
-          ],
-          stepIndent: 6,
-          withIndent: 6
-        }
+        severity: DiagnosticSeverity.Error
       }
     ]);
   });
@@ -315,32 +294,7 @@ jobs:
             line: 7
           }
         },
-        severity: DiagnosticSeverity.Error,
-        code: "missing-required-inputs",
-        data: {
-          action: {
-            name: "cache",
-            owner: "actions",
-            ref: "v1"
-          },
-          hasWithKey: true,
-          insertPosition: {
-            character: 0,
-            line: 9
-          },
-          missingInputs: [
-            {
-              default: undefined,
-              name: "path"
-            },
-            {
-              default: undefined,
-              name: "key"
-            }
-          ],
-          stepIndent: 6,
-          withIndent: 6
-        }
+        severity: DiagnosticSeverity.Error
       }
     ]);
   });
@@ -369,32 +323,7 @@ jobs:
             line: 6
           }
         },
-        severity: DiagnosticSeverity.Error,
-        code: "missing-required-inputs",
-        data: {
-          action: {
-            name: "cache",
-            owner: "actions",
-            ref: "v1"
-          },
-          hasWithKey: false,
-          insertPosition: {
-            character: 0,
-            line: 7
-          },
-          missingInputs: [
-            {
-              default: undefined,
-              name: "path"
-            },
-            {
-              default: undefined,
-              name: "key"
-            }
-          ],
-          stepIndent: 6,
-          withIndent: undefined
-        }
+        severity: DiagnosticSeverity.Error
       }
     ]);
   });

languageservice/src/validate.expressions.test.ts

@@ -635,7 +635,7 @@ jobs:
         fail-fast: true
         matrix:
           node: [14, 16]
-      uses: ./reusable-workflow-with-inputs.yaml
+      uses: ./.github/workflows/reusable-workflow-with-inputs.yaml
       with:
         username: User-\${{ strategy.fail-fast }}
   `;
@@ -654,7 +654,7 @@ jobs:
       strategy:
         matrix:
           node: [14, 16]
-      uses: ./reusable-workflow-with-inputs.yaml
+      uses: ./.github/workflows/reusable-workflow-with-inputs.yaml
       with:
         username: \${{ matrix.node }}
   `;

languageservice/src/validate.test.ts

@@ -181,7 +181,7 @@ jobs:
 
     expect(result.length).toBe(1);
     expect(result[0]).toEqual({
-      message: "Invalid cron string",
+      message: "Invalid cron expression. Expected format: '* * * * *' (minute hour day month weekday)",
       range: {
         end: {
           character: 21,
@@ -195,6 +195,95 @@ jobs:
     } as Diagnostic);
   });
 
+  it("cron with interval less than 5 minutes shows warning", async () => {
+    const result = await validate(
+      createDocument(
+        "wf.yaml",
+        `on:
+  schedule:
+    - cron: '*/1 * * * *'
+jobs:
+  build:
+    runs-on: ubuntu-latest`
+      ),
+      {valueProviderConfig: defaultValueProviders}
+    );
+
+    expect(result.length).toBe(1);
+    expect(result[0]).toEqual({
+      message: "Runs every minute. Note: Actions schedules run at most every 5 minutes.",
+      severity: DiagnosticSeverity.Warning,
+      code: "on-schedule",
+      codeDescription: {
+        href: "https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#onschedule"
+      },
+      range: {
+        end: {
+          character: 25,
+          line: 2
+        },
+        start: {
+          character: 12,
+          line: 2
+        }
+      }
+    } as Diagnostic);
+  });
+
+  it("cron with interval of 5 minutes or more shows info", async () => {
+    const result = await validate(
+      createDocument(
+        "wf.yaml",
+        `on:
+  schedule:
+    - cron: '*/5 * * * *'
+jobs:
+  build:
+    runs-on: ubuntu-latest`
+      ),
+      {valueProviderConfig: defaultValueProviders}
+    );
+
+    expect(result.length).toBe(1);
+    expect(result[0]).toEqual({
+      message: "Runs every 5 minutes",
+      severity: DiagnosticSeverity.Information,
+      code: "on-schedule",
+      codeDescription: {
+        href: "https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#onschedule"
+      },
+      range: {
+        end: {
+          character: 25,
+          line: 2
+        },
+        start: {
+          character: 12,
+          line: 2
+        }
+      }
+    } as Diagnostic);
+  });
+
+  it("cron with comma-separated minutes less than 5 apart shows warning", async () => {
+    const result = await validate(
+      createDocument(
+        "wf.yaml",
+        `on:
+  schedule:
+    - cron: '0,2 * * * *'
+jobs:
+  build:
+    runs-on: ubuntu-latest`
+      ),
+      {valueProviderConfig: defaultValueProviders}
+    );
+
+    expect(result.length).toBe(1);
+    expect(result[0]?.severity).toBe(DiagnosticSeverity.Warning);
+    expect(result[0]?.message).toContain("Note: Actions schedules run at most every 5 minutes.");
+  });
+
   it("invalid YAML", async () => {
     // This YAML has some mismatched single-quotes, which causes the string to be terminated early
     // within the fromJSON() expression.

languageservice/src/validate.ts

@@ -2,6 +2,7 @@ import {Lexer, Parser, data} from "@actions/expressions";
 import {Expr, FunctionCall, Literal, Logical} from "@actions/expressions/ast";
 import {ParseWorkflowResult, WorkflowTemplate, isBasicExpression, isString} from "@actions/workflow-parser";
 import {ErrorPolicy} from "@actions/workflow-parser/model/convert";
+import {getCronDescription, hasCronIntervalLessThan5Minutes} from "@actions/workflow-parser/model/converter/cron";
 import {ensureStatusFunction} from "@actions/workflow-parser/model/converter/if-condition";
 import {splitAllowedContext} from "@actions/workflow-parser/templates/allowed-context";
 import {BasicExpressionToken} from "@actions/workflow-parser/templates/tokens/basic-expression-token";
@@ -27,6 +28,9 @@ import {validateAction} from "./validate-action";
 import {ValueProviderConfig, ValueProviderKind} from "./value-providers/config";
 import {defaultValueProviders} from "./value-providers/default";
 
+const CRON_SCHEDULE_DOCS_URL =
+  "https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#onschedule";
+
 export type ValidationConfig = {
   valueProviderConfig?: ValueProviderConfig;
   contextProviderConfig?: ContextProviderConfig;
@@ -143,11 +147,34 @@ async function additionalValidations(
       }
     }
 
+    // Validate step uses field format
+    if (isString(token) && token.range && validationDefinition?.key === "step-uses") {
+      validateStepUsesFormat(diagnostics, token);
+    }
+
+    // Validate action metadata (inputs, required fields) for regular steps
     if (token.definition?.key === "regular-step" && token.range) {
       const context = getProviderContext(documentUri, template, root, token.range);
       await validateAction(diagnostics, token, context.step, config);
     }
 
+    // Validate job-level reusable workflow uses field format
+    if (
+      isString(token) &&
+      token.range &&
+      key &&
+      isString(key) &&
+      key.value === "uses" &&
+      parent?.definition?.key === "workflow-job"
+    ) {
+      validateWorkflowUsesFormat(diagnostics, token);
+    }
+
+    // Validate cron expressions - warn if interval is less than 5 minutes
+    if (isString(token) && token.range && validationDefinition?.key === "cron-pattern") {
+      validateCronExpression(diagnostics, token);
+    }
+
     // Allowed values coming from the schema have already been validated. Only check if
     // a value provider is defined for a token and if it is, validate the values match.
     if (token.range && validationDefinition) {
@@ -198,6 +225,357 @@ function invalidValue(diagnostics: Diagnostic[], token: StringToken, kind: Value
   }
 }
 
+/**
+ * Validates cron expressions and provides diagnostics for valid cron schedules.
+ * Shows a warning if the interval is less than 5 minutes (since GitHub Actions
+ * schedules run at most every 5 minutes), otherwise shows an info message.
+ */
+function validateCronExpression(diagnostics: Diagnostic[], token: StringToken): void {
+  const cronValue = token.value;
+
+  // Ensure we have a range for diagnostics
+  if (!token.range) {
+    return;
+  }
+
+  // Only check valid cron expressions - invalid ones are already caught by the parser
+  const description = getCronDescription(cronValue);
+  if (!description) {
+    return;
+  }
+
+  // Check if the cron specifies an interval less than 5 minutes
+  if (hasCronIntervalLessThan5Minutes(cronValue)) {
+    diagnostics.push({
+      message: `${description}. Note: Actions schedules run at most every 5 minutes.`,
+      range: mapRange(token.range),
+      severity: DiagnosticSeverity.Warning,
+      code: "on-schedule",
+      codeDescription: {
+        href: CRON_SCHEDULE_DOCS_URL
+      }
+    });
+  } else {
+    // Show info message for valid cron expressions
+    diagnostics.push({
+      message: description,
+      range: mapRange(token.range),
+      severity: DiagnosticSeverity.Information,
+      code: "on-schedule",
+      codeDescription: {
+        href: CRON_SCHEDULE_DOCS_URL
+      }
+    });
+  }
+}
+
+/**
+ * Validates the format of a step's `uses` field.
+ *
+ * Valid formats:
+ * - docker://image:tag
+ * - ./local/path
+ * - .\local\path (Windows)
+ * - {owner}/{repo}@{ref}
+ * - {owner}/{repo}/{path}@{ref}
+ */
+function validateStepUsesFormat(diagnostics: Diagnostic[], token: StringToken): void {
+  const uses = token.value;
+
+  // Empty uses value
+  if (!uses) {
+    diagnostics.push({
+      message: "`uses' value in action cannot be blank",
+      severity: DiagnosticSeverity.Error,
+      range: mapRange(token.range),
+      code: "invalid-uses-format"
+    });
+    return;
+  }
+
+  // Docker image reference - always valid format
+  if (uses.startsWith("docker://")) {
+    return;
+  }
+
+  // Local action path - always valid format
+  if (uses.startsWith("./") || uses.startsWith(".\\")) {
+    return;
+  }
+
+  // Remote action: must be {owner}/{repo}[/path]@{ref}
+  const atSegments = uses.split("@");
+
+  // Must have exactly one @
+  if (atSegments.length !== 2) {
+    addStepUsesFormatError(diagnostics, token);
+    return;
+  }
+
+  const [repoPath, gitRef] = atSegments;
+
+  // Ref cannot be empty
+  if (!gitRef) {
+    addStepUsesFormatError(diagnostics, token);
+    return;
+  }
+
+  // Split by / or \ to get path segments
+  const pathSegments = repoPath.split(/[\\/]/);
+
+  // Must have at least owner and repo (both non-empty)
+  if (pathSegments.length < 2 || !pathSegments[0] || !pathSegments[1]) {
+    addStepUsesFormatError(diagnostics, token);
+    return;
+  }
+
+  // Check if this is a reusable workflow reference (should be at job level, not step)
+  // Path would be like: owner/repo/.github/workflows/file.yml
+  if (pathSegments.length >= 4 && pathSegments[2] === ".github" && pathSegments[3] === "workflows") {
+    diagnostics.push({
+      message: "Reusable workflows should be referenced at the top-level `jobs.<job_id>.uses` key, not within steps",
+      severity: DiagnosticSeverity.Error,
+      range: mapRange(token.range),
+      code: "invalid-uses-format"
+    });
+    return;
+  }
+}
+
+function addStepUsesFormatError(diagnostics: Diagnostic[], token: StringToken): void {
+  diagnostics.push({
+    message: `Expected format {owner}/{repo}[/path]@{ref}. Actual '${token.value}'`,
+    severity: DiagnosticSeverity.Error,
+    range: mapRange(token.range),
+    code: "invalid-uses-format"
+  });
+}
+
+/**
+ * Validates the format of a job's `uses` field (reusable workflow reference).
+ *
+ * Valid formats:
+ * - {owner}/{repo}/.github/workflows/{filename}.yml@{ref}
+ * - {owner}/{repo}/.github/workflows/{filename}.yaml@{ref}
+ * - {owner}/{repo}/.github/workflows-lab/{filename}.yml@{ref}
+ * - {owner}/{repo}/.github/workflows-lab/{filename}.yaml@{ref}
+ * - ./.github/workflows/{filename}.yml
+ * - ./.github/workflows/{filename}.yaml
+ * - ./.github/workflows-lab/{filename}.yml
+ * - ./.github/workflows-lab/{filename}.yaml
+ */
+function validateWorkflowUsesFormat(diagnostics: Diagnostic[], token: StringToken): void {
+  const uses = token.value;
+
+  // Local workflow reference
+  if (uses.startsWith("./.github/workflows/") || uses.startsWith("./.github/workflows-lab/")) {
+    // Cannot have @ version for local workflows
+    if (uses.includes("@")) {
+      addWorkflowUsesFormatError(diagnostics, token, "cannot specify version when calling local workflows");
+      return;
+    }
+
+    // Must have .yml or .yaml extension
+    if (!uses.endsWith(".yml") && !uses.endsWith(".yaml")) {
+      addWorkflowUsesFormatError(
+        diagnostics,
+        token,
+        "workflow file should have either a '.yml' or '.yaml' file extension"
+      );
+      return;
+    }
+
+    // Must be at top level of .github/workflows/ or .github/workflows-lab/ (no subdirectories)
+    const pathParts = uses.split("/");
+    if (pathParts.length !== 4) {
+      // Expected: ".", ".github", "workflows" or "workflows-lab", "filename.yml"
+      addWorkflowUsesFormatError(
+        diagnostics,
+        token,
+        "workflows must be defined at the top level of the .github/workflows/ directory"
+      );
+      return;
+    }
+
+    // Filename cannot be just the extension
+    const filename = pathParts[3];
+    if (filename === ".yml" || filename === ".yaml") {
+      addWorkflowUsesFormatError(diagnostics, token, "invalid workflow file name");
+      return;
+    }
+
+    return;
+  }
+
+  // Malformed local workflow reference (starts with ./ but not in .github/workflows)
+  if (uses.startsWith("./")) {
+    addWorkflowUsesFormatError(diagnostics, token, "local workflow references must be rooted in '.github/workflows'");
+    return;
+  }
+
+  // Remote workflow reference: must have @ for version
+  const atSegments = uses.split("@");
+  if (atSegments.length === 1) {
+    addWorkflowUsesFormatError(diagnostics, token, "no version specified");
+    return;
+  }
+  if (atSegments.length > 2) {
+    addWorkflowUsesFormatError(diagnostics, token, "too many '@' in workflow reference");
+    return;
+  }
+
+  const [pathPart, version] = atSegments;
+
+  // Version cannot be empty
+  if (!version) {
+    addWorkflowUsesFormatError(diagnostics, token, "no version specified");
+    return;
+  }
+
+  // Must contain .github/workflows or .github/workflows-lab path
+  const workflowsMatch = pathPart.match(/\.github\/workflows(-lab)?\//);
+  if (!workflowsMatch || workflowsMatch.index === undefined) {
+    addWorkflowUsesFormatError(diagnostics, token, "references to workflows must be rooted in '.github/workflows'");
+    return;
+  }
+
+  // Split to get owner/repo and path
+  const pathIdx = workflowsMatch.index;
+  const nwoPart = pathPart.substring(0, pathIdx);
+  const workflowPath = pathPart.substring(pathIdx);
+
+  // Validate NWO part: must be owner/repo/
+  const nwoSegments = nwoPart.split("/").filter(s => s.length > 0);
+  if (nwoSegments.length !== 2) {
+    addWorkflowUsesFormatError(
+      diagnostics,
+      token,
+      "references to workflows must be prefixed with format 'owner/repository/' or './' for local workflows"
+    );
+    return;
+  }
+
+  // Validate owner and repo names
+  const [owner, repo] = nwoSegments;
+  const nwoError = validateNWO(owner, repo);
+  if (nwoError) {
+    addWorkflowUsesFormatError(diagnostics, token, nwoError);
+    return;
+  }
+
+  // Validate ref/version format
+  const refError = validateRefName(version);
+  if (refError) {
+    addWorkflowUsesFormatError(diagnostics, token, refError);
+    return;
+  }
+
+  // Validate workflow path is at top level
+  const workflowPathParts = workflowPath.split("/");
+  if (workflowPathParts.length !== 3) {
+    // Expected: ".github", "workflows" or "workflows-lab", "filename.yml"
+    addWorkflowUsesFormatError(
+      diagnostics,
+      token,
+      "workflows must be defined at the top level of the .github/workflows/ directory"
+    );
+    return;
+  }
+
+  // Must have .yml or .yaml extension
+  const filename = workflowPathParts[2];
+  if (!filename.endsWith(".yml") && !filename.endsWith(".yaml")) {
+    addWorkflowUsesFormatError(
+      diagnostics,
+      token,
+      "workflow file should have either a '.yml' or '.yaml' file extension"
+    );
+    return;
+  }
+
+  // Filename cannot be just the extension
+  if (filename === ".yml" || filename === ".yaml") {
+    addWorkflowUsesFormatError(diagnostics, token, "invalid workflow file name");
+    return;
+  }
+}
+
+function addWorkflowUsesFormatError(diagnostics: Diagnostic[], token: StringToken, reason: string): void {
+  diagnostics.push({
+    message: `Invalid workflow reference '${token.value}': ${reason}`,
+    severity: DiagnosticSeverity.Error,
+    range: mapRange(token.range),
+    code: "invalid-workflow-uses-format"
+  });
+}
+
+/**
+ * Validates the git ref/version format.
+ * Based on Launch's ValidateRefName function.
+ */
+function validateRefName(refname: string): string | undefined {
+  if (refname.length === 0) {
+    return "no version specified";
+  }
+
+  // Cannot be the single character '@'
+  if (refname === "@") {
+    return "version cannot be the single character '@'";
+  }
+
+  // Cannot have certain invalid characters or sequences
+  const invalidSequences = ["?", "*", "[", "]", "\\", "~", "^", ":", "@{", "..", "//"];
+  for (const seq of invalidSequences) {
+    if (refname.includes(seq)) {
+      return `invalid character '${seq}' in version`;
+    }
+  }
+
+  // Cannot begin or end with a slash '/' or a dot '.'
+  if (refname.startsWith("/") || refname.endsWith("/") || refname.startsWith(".") || refname.endsWith(".")) {
+    return "version cannot begin or end with a slash '/' or a dot '.'";
+  }
+
+  // No slash-separated component can begin with a dot '.' or end with the sequence '.lock'
+  const components = refname.split("/");
+  for (const component of components) {
+    if (component.startsWith(".") || component.endsWith(".lock")) {
+      return `invalid version: ${refname}`;
+    }
+  }
+
+  // No ASCII control characters or whitespace
+  // eslint-disable-next-line no-control-regex
+  if (/[\x00-\x1f\x7f]/.test(refname)) {
+    return "version cannot have ASCII control characters";
+  }
+
+  if (/\s/.test(refname)) {
+    return "version cannot have whitespace";
+  }
+
+  return undefined;
+}
+
+/**
+ * Validates owner and repository names.
+ * Based on Launch's ValidateNWO function.
+ */
+function validateNWO(owner: string, repo: string): string | undefined {
+  // Owner name: can have word chars, dots, and hyphens
+  // \w in JS regex is [a-zA-Z0-9_]
+  if (!/^[\w.-]+$/.test(owner)) {
+    return "owner name must be a valid repository owner name";
+  }
+
+  // Repository name: can have word chars, dots, and hyphens
+  if (!/^[\w.-]+$/.test(repo)) {
+    return "repository name is invalid";
+  }
+
+  return undefined;
+}
+
 function getProviderContext(
   documentUri: URI,
   template: WorkflowTemplate,

languageservice/src/validate.uses-format.test.ts

@@ -0,0 +1,894 @@
+import {DiagnosticSeverity} from "vscode-languageserver-types";
+import {validate} from "./validate";
+import {createDocument} from "./test-utils/document";
+import {clearCache} from "./utils/workflow-cache";
+
+beforeEach(() => {
+  clearCache();
+});
+
+describe("validate uses format", () => {
+  describe("valid formats", () => {
+    it("standard org/repo@ref", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("org/repo with path @ref", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/aws/ec2@main
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("org/repo with deep path @ref", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/aws/nested/deep/path@v1
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("docker image", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: docker://alpine:3.8
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("docker image with registry", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: docker://gcr.io/my-project/my-image:latest
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("local path with ./", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: ./my-action
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("local path with ./ and subdirectories", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: ./.github/actions/my-action
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("local path with .\\ (Windows)", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: .\\my-action
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("SHA ref", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("branch ref", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: owner/repo@feature/my-branch
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("invalid formats", () => {
+    it("missing @ref", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message: "Expected format {owner}/{repo}[/path]@{ref}. Actual 'actions/checkout'",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 5, character: 12},
+            end: {line: 5, character: 28}
+          },
+          code: "invalid-uses-format"
+        }
+      ]);
+    });
+
+    it("empty ref", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message: "Expected format {owner}/{repo}[/path]@{ref}. Actual 'actions/checkout@'",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 5, character: 12},
+            end: {line: 5, character: 29}
+          },
+          code: "invalid-uses-format"
+        }
+      ]);
+    });
+
+    it("missing org/owner", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: checkout@v4
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message: "Expected format {owner}/{repo}[/path]@{ref}. Actual 'checkout@v4'",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 5, character: 12},
+            end: {line: 5, character: 23}
+          },
+          code: "invalid-uses-format"
+        }
+      ]);
+    });
+
+    it("empty owner", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: /repo@v4
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message: "Expected format {owner}/{repo}[/path]@{ref}. Actual '/repo@v4'",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 5, character: 12},
+            end: {line: 5, character: 20}
+          },
+          code: "invalid-uses-format"
+        }
+      ]);
+    });
+
+    it("empty repo", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: owner/@v4
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message: "Expected format {owner}/{repo}[/path]@{ref}. Actual 'owner/@v4'",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 5, character: 12},
+            end: {line: 5, character: 21}
+          },
+          code: "invalid-uses-format"
+        }
+      ]);
+    });
+
+    it("multiple @ symbols", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4@extra
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message: "Expected format {owner}/{repo}[/path]@{ref}. Actual 'actions/checkout@v4@extra'",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 5, character: 12},
+            end: {line: 5, character: 37}
+          },
+          code: "invalid-uses-format"
+        }
+      ]);
+    });
+
+    it("just a name with no slash", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: checkout
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message: "Expected format {owner}/{repo}[/path]@{ref}. Actual 'checkout'",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 5, character: 12},
+            end: {line: 5, character: 20}
+          },
+          code: "invalid-uses-format"
+        }
+      ]);
+    });
+
+    it("empty uses value", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: ""
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toContainEqual({
+        message: "`uses' value in action cannot be blank",
+        severity: DiagnosticSeverity.Error,
+        range: {
+          start: {line: 5, character: 12},
+          end: {line: 5, character: 14}
+        },
+        code: "invalid-uses-format"
+      });
+    });
+
+    it("reusable workflow in step", async () => {
+      const input = `on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: owner/repo/.github/workflows/test.yml@main
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message:
+            "Reusable workflows should be referenced at the top-level `jobs.<job_id>.uses` key, not within steps",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 5, character: 12},
+            end: {line: 5, character: 54}
+          },
+          code: "invalid-uses-format"
+        }
+      ]);
+    });
+  });
+});
+
+describe("workflow uses format validation", () => {
+  beforeEach(() => {
+    clearCache();
+  });
+
+  describe("valid formats", () => {
+    it("local workflow path", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: ./.github/workflows/test.yml
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("local workflow path with yaml extension", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: ./.github/workflows/test.yaml
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("remote workflow with version", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml@v1
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("remote workflow with sha ref", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml@abc123
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("remote workflow with branch ref", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml@main
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("remote workflow with yaml extension", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yaml@v1
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("local workflows-lab path", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: ./.github/workflows-lab/test.yml
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("local workflows-lab path with yaml extension", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: ./.github/workflows-lab/test.yaml
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+
+    it("remote workflows-lab with version", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows-lab/test.yml@v1
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("invalid formats", () => {
+    it("remote workflow missing version", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message: "Invalid workflow reference 'owner/repo/.github/workflows/test.yml': no version specified",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 3, character: 10},
+            end: {line: 3, character: 47}
+          },
+          code: "invalid-workflow-uses-format"
+        }
+      ]);
+    });
+
+    it("local workflow with version", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: ./.github/workflows/test.yml@v1
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message:
+            "Invalid workflow reference './.github/workflows/test.yml@v1': cannot specify version when calling local workflows",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 3, character: 10},
+            end: {line: 3, character: 41}
+          },
+          code: "invalid-workflow-uses-format"
+        }
+      ]);
+    });
+
+    it("malformed local path not in .github/workflows", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: ./foo/bar.yml
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message:
+            "Invalid workflow reference './foo/bar.yml': local workflow references must be rooted in '.github/workflows'",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 3, character: 10},
+            end: {line: 3, character: 23}
+          },
+          code: "invalid-workflow-uses-format"
+        }
+      ]);
+    });
+
+    it("missing .github/workflows path", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/test.yml@v1
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message:
+            "Invalid workflow reference 'owner/repo/test.yml@v1': references to workflows must be rooted in '.github/workflows'",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 3, character: 10},
+            end: {line: 3, character: 32}
+          },
+          code: "invalid-workflow-uses-format"
+        }
+      ]);
+    });
+
+    it("invalid file extension", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.txt@v1
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message:
+            "Invalid workflow reference 'owner/repo/.github/workflows/test.txt@v1': workflow file should have either a '.yml' or '.yaml' file extension",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 3, character: 10},
+            end: {line: 3, character: 50}
+          },
+          code: "invalid-workflow-uses-format"
+        }
+      ]);
+    });
+
+    it("no extension", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test@v1
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message:
+            "Invalid workflow reference 'owner/repo/.github/workflows/test@v1': workflow file should have either a '.yml' or '.yaml' file extension",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 3, character: 10},
+            end: {line: 3, character: 46}
+          },
+          code: "invalid-workflow-uses-format"
+        }
+      ]);
+    });
+
+    it("just a ref", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: test.yml@v1
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message:
+            "Invalid workflow reference 'test.yml@v1': references to workflows must be rooted in '.github/workflows'",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 3, character: 10},
+            end: {line: 3, character: 21}
+          },
+          code: "invalid-workflow-uses-format"
+        }
+      ]);
+    });
+
+    it("local without .github/workflows", async () => {
+      const input = `on: push
+jobs:
+  test:
+    uses: ./workflows/test.yml
+`;
+      const result = await validate(createDocument("wf.yaml", input));
+      expect(result).toEqual([
+        {
+          message:
+            "Invalid workflow reference './workflows/test.yml': local workflow references must be rooted in '.github/workflows'",
+          severity: DiagnosticSeverity.Error,
+          range: {
+            start: {line: 3, character: 10},
+            end: {line: 3, character: 30}
+          },
+          code: "invalid-workflow-uses-format"
+        }
+      ]);
+    });
+
+    describe("invalid ref/version format", () => {
+      it("empty version after @", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml@
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message: "Invalid workflow reference 'owner/repo/.github/workflows/test.yml@': no version specified",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 48}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+
+      it("version with invalid character ?", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml@v1?
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message:
+              "Invalid workflow reference 'owner/repo/.github/workflows/test.yml@v1?': invalid character '?' in version",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 51}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+
+      it("version with double dots", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml@v1..v2
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message:
+              "Invalid workflow reference 'owner/repo/.github/workflows/test.yml@v1..v2': invalid character '..' in version",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 54}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+
+      it("version ending with dot", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml@v1.
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message:
+              "Invalid workflow reference 'owner/repo/.github/workflows/test.yml@v1.': version cannot begin or end with a slash '/' or a dot '.'",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 51}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+
+      it("version starting with slash", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml@/v1
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message:
+              "Invalid workflow reference 'owner/repo/.github/workflows/test.yml@/v1': version cannot begin or end with a slash '/' or a dot '.'",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 51}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+
+      it("version ending with .lock", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml@refs/heads/main.lock
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message:
+              "Invalid workflow reference 'owner/repo/.github/workflows/test.yml@refs/heads/main.lock': invalid version: refs/heads/main.lock",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 68}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+
+      it("version with whitespace", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml@v1 && rm -rf
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message:
+              "Invalid workflow reference 'owner/repo/.github/workflows/test.yml@v1 && rm -rf': version cannot have whitespace",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 60}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+
+      it("version with backslash", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/test.yml@v1\\1
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message:
+              "Invalid workflow reference 'owner/repo/.github/workflows/test.yml@v1\\1': invalid character '\\' in version",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 52}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+    });
+
+    describe("invalid owner/repo names", () => {
+      it("owner with invalid characters", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner*/repo/.github/workflows/test.yml@v1
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message:
+              "Invalid workflow reference 'owner*/repo/.github/workflows/test.yml@v1': owner name must be a valid repository owner name",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 51}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+
+      it("repo with invalid characters", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner/repo!name/.github/workflows/test.yml@v1
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message:
+              "Invalid workflow reference 'owner/repo!name/.github/workflows/test.yml@v1': repository name is invalid",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 55}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+
+      it("owner with spaces", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner name/repo/.github/workflows/test.yml@v1
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message:
+              "Invalid workflow reference 'owner name/repo/.github/workflows/test.yml@v1': owner name must be a valid repository owner name",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 55}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+    });
+
+    describe("invalid workflow filename", () => {
+      it("filename is just .yml", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/.yml@v1
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message: "Invalid workflow reference 'owner/repo/.github/workflows/.yml@v1': invalid workflow file name",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 46}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+
+      it("filename is just .yaml", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: owner/repo/.github/workflows/.yaml@v1
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message: "Invalid workflow reference 'owner/repo/.github/workflows/.yaml@v1': invalid workflow file name",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 47}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+
+      it("local workflow filename is just .yml", async () => {
+        const input = `on: push
+jobs:
+  test:
+    uses: ./.github/workflows/.yml
+`;
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([
+          {
+            message: "Invalid workflow reference './.github/workflows/.yml': invalid workflow file name",
+            severity: DiagnosticSeverity.Error,
+            range: {
+              start: {line: 3, character: 10},
+              end: {line: 3, character: 34}
+            },
+            code: "invalid-workflow-uses-format"
+          }
+        ]);
+      });
+    });
+  });
+});

languageservice/src/validate.workflow-references.test.ts

@@ -43,7 +43,7 @@ on: push
 
 jobs:
   build:
-    uses: monalisa/octocat/workflow.yaml@not-a-branch
+    uses: monalisa/octocat/.github/workflows/workflow.yaml@not-a-branch
 `;
     const result = await validate(createDocument("wf.yaml", input), {
       fileProvider: testFileProvider
@@ -58,7 +58,7 @@ jobs:
             line: 5
           },
           end: {
-            character: 53,
+            character: 71,
             line: 5
           }
         }
@@ -72,7 +72,7 @@ on: push
 
 jobs:
   build:
-    uses: monalisa/octocat/workflow.yaml@main
+    uses: monalisa/octocat/.github/workflows/workflow.yaml@main
 `;
     const result = await validate(createDocument("wf.yaml", input), {
       fileProvider: testFileProvider
@@ -87,7 +87,7 @@ on: push
 
 jobs:
   build:
-    uses: ./reusable-workflow.yaml
+    uses: ./.github/workflows/reusable-workflow.yaml
 `;
     const result = await validate(createDocument("wf.yaml", input), {
       fileProvider: testFileProvider
@@ -102,7 +102,7 @@ on: push
 
 jobs:
   build:
-    uses: ./reusable-workflow-with-inputs.yaml
+    uses: ./.github/workflows/reusable-workflow-with-inputs.yaml
     secrets:
       envPAT: pat
 `;
@@ -119,7 +119,7 @@ jobs:
             line: 5
           },
           end: {
-            character: 46,
+            character: 64,
             line: 5
           }
         }
@@ -133,7 +133,7 @@ on: push
 
 jobs:
   build:
-    uses: ./reusable-workflow-with-inputs.yaml
+    uses: ./.github/workflows/reusable-workflow-with-inputs.yaml
     with:
       username: monalisa
     secrets:

lerna.json

@@ -6,5 +6,5 @@
     "languageservice",
     "languageserver"
   ],
-  "version": "0.3.20"
+  "version": "0.3.21"
 }

workflow-parser/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@actions/workflow-parser",
-  "version": "0.3.20",
+  "version": "0.3.21",
   "license": "MIT",
   "type": "module",
   "source": "./src/index.ts",
@@ -45,7 +45,7 @@
     "watch": "tsc --build tsconfig.build.json --watch"
   },
   "dependencies": {
-    "@actions/expressions": "^0.3.20",
+    "@actions/expressions": "^0.3.21",
     "cronstrue": "^2.21.0",
     "yaml": "^2.0.0-8"
   },

workflow-parser/src/model/converter/cron.test.ts

@@ -1,4 +1,4 @@
-import {isValidCron, getCronDescription} from "./cron";
+import {isValidCron, getCronDescription, hasCronIntervalLessThan5Minutes} from "./cron";
 
 describe("cron", () => {
   describe("valid cron", () => {
@@ -66,14 +66,54 @@ describe("cron", () => {
 
   describe("getCronDescription", () => {
     it(`Produces a sentence for valid cron`, () => {
-      expect(getCronDescription("0 * * * *")).toEqual(
-        "Runs every hour\n\n" +
-          "Actions schedules run at most every 5 minutes. [Learn more](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#onschedule)"
-      );
+      expect(getCronDescription("0 * * * *")).toEqual("Runs every hour");
     });
 
     it(`Returns nothing for invalid cron`, () => {
       expect(getCronDescription("* * * * * *")).toBeUndefined();
     });
   });
+
+  describe("hasCronIntervalLessThan5Minutes", () => {
+    it("returns true for step expressions with interval < 5 min", () => {
+      expect(hasCronIntervalLessThan5Minutes("*/1 * * * *")).toBe(true);
+      expect(hasCronIntervalLessThan5Minutes("*/4 * * * *")).toBe(true);
+    });
+
+    it("returns false for step expressions with interval >= 5 min", () => {
+      expect(hasCronIntervalLessThan5Minutes("*/5 * * * *")).toBe(false);
+      expect(hasCronIntervalLessThan5Minutes("*/15 * * * *")).toBe(false);
+    });
+
+    it("returns true for comma-separated values with gap < 5 min", () => {
+      expect(hasCronIntervalLessThan5Minutes("0,2,4 * * * *")).toBe(true);
+      expect(hasCronIntervalLessThan5Minutes("0,10,12 * * * *")).toBe(true);
+    });
+
+    it("returns false for comma-separated values with gap >= 5 min", () => {
+      expect(hasCronIntervalLessThan5Minutes("0,10,20 * * * *")).toBe(false);
+      expect(hasCronIntervalLessThan5Minutes("0,30 * * * *")).toBe(false);
+    });
+
+    it("returns true for comma-separated values with wrap-around gap < 5 min", () => {
+      expect(hasCronIntervalLessThan5Minutes("0,58 * * * *")).toBe(true);
+      expect(hasCronIntervalLessThan5Minutes("2,59 * * * *")).toBe(true);
+    });
+
+    it("returns true for * (every minute)", () => {
+      expect(hasCronIntervalLessThan5Minutes("* * * * *")).toBe(true);
+    });
+
+    it("returns true for range expressions (runs every minute in range)", () => {
+      expect(hasCronIntervalLessThan5Minutes("0-4 * * * *")).toBe(true);
+    });
+
+    it("returns false for single value (hourly)", () => {
+      expect(hasCronIntervalLessThan5Minutes("0 * * * *")).toBe(false);
+    });
+
+    it("returns false for invalid cron", () => {
+      expect(hasCronIntervalLessThan5Minutes("invalid")).toBe(false);
+    });
+  });
 });

workflow-parser/src/model/converter/cron.ts

@@ -8,6 +8,78 @@ type Range = {
   names?: Record<string, number>;
 };
 
+/**
+ * Checks if a cron expression specifies an interval shorter than 5 minutes.
+ * GitHub Actions schedules run at most every 5 minutes, so intervals < 5 min won't work as expected.
+ */
+export function hasCronIntervalLessThan5Minutes(cron: string): boolean {
+  if (!isValidCron(cron)) {
+    return false;
+  }
+
+  const parts = cron.split(/ +/);
+  const minutePart = parts[0];
+
+  // Parse the minute field to determine the effective interval
+  return getMinuteInterval(minutePart) < 5;
+}
+
+/**
+ * Gets the minimum interval in minutes between cron executions based on the minute field.
+ * Returns 60 if there's only one execution per hour, otherwise returns the minimum gap.
+ */
+function getMinuteInterval(minutePart: string): number {
+  // Handle step expressions like */1, */3, 0-59/2
+  if (minutePart.includes("/")) {
+    const [, step] = minutePart.split("/");
+    const stepNum = parseInt(step, 10);
+    if (!isNaN(stepNum) && stepNum > 0) {
+      return stepNum;
+    }
+  }
+
+  // Handle comma-separated values like 0,2,4 or 0,1,5,10
+  if (minutePart.includes(",")) {
+    const values = minutePart
+      .split(",")
+      .map(v => parseInt(v, 10))
+      .filter(n => !isNaN(n))
+      .sort((a, b) => a - b);
+    if (values.length >= 2) {
+      let minGap = 60;
+      for (let i = 1; i < values.length; i++) {
+        const gap = values[i] - values[i - 1];
+        if (gap < minGap) {
+          minGap = gap;
+        }
+      }
+      // Check wrap-around gap from last minute to first minute of next hour
+      const wrapGap = values[0] + 60 - values[values.length - 1];
+      if (wrapGap < minGap) {
+        minGap = wrapGap;
+      }
+      return minGap;
+    }
+  }
+
+  // Handle range expressions like 0-4 (runs every minute from 0-4)
+  if (minutePart.includes("-") && !minutePart.includes("/")) {
+    const [start, end] = minutePart.split("-").map(v => parseInt(v, 10));
+    if (!isNaN(start) && !isNaN(end) && end > start) {
+      // A range without step means every minute in that range
+      return 1;
+    }
+  }
+
+  // * means every minute
+  if (minutePart === "*") {
+    return 1;
+  }
+
+  // Single value or unrecognized pattern - assume hourly (60 min interval)
+  return 60;
+}
+
 export function isValidCron(cron: string): boolean {
   // https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#schedule
 
@@ -46,11 +118,7 @@ export function getCronDescription(cronspec: string): string | undefined {
   }
 
   // Make first character lowercase
-  let result = "Runs " + desc.charAt(0).toLowerCase() + desc.slice(1);
-  result +=
-    "\n\nActions schedules run at most every 5 minutes." +
-    " [Learn more](https://docs.github.com/actions/using-workflows/workflow-syntax-for-github-actions#onschedule)";
-  return result;
+  return "Runs " + desc.charAt(0).toLowerCase() + desc.slice(1);
 }
 
 function validateCronPart(value: string, range: Range, allowSeparators = true): boolean {

workflow-parser/src/model/converter/events.ts

@@ -158,7 +158,7 @@ function convertSchedule(context: TemplateContext, token: SequenceToken): Schedu
         const cron = schedule.value.assertString(`schedule cron`);
         // Validate the cron string
         if (!isValidCron(cron.value)) {
-          context.error(cron, "Invalid cron string");
+          context.error(cron, "Invalid cron expression. Expected format: '* * * * *' (minute hour day month weekday)");
         }
         result.push({cron: cron.value});
       } else {