Show action input descriptions on hover

actions-languageserver/src/connection.ts

@@ -23,6 +23,7 @@ import {TTLCache} from "./utils/cache";
 import {valueProviders} from "./value-providers";
 import {getActionInputs} from "./value-providers/action-inputs";
 import {Commands} from "./commands";
+import {descriptionProvider} from "./description-provider";
 
 export function initConnection(connection: Connection) {
   const documents: TextDocuments<TextDocument> = new TextDocuments(TextDocument);
@@ -120,7 +121,9 @@ export function initConnection(connection: Connection) {
   });
 
   connection.onHover(async ({position, textDocument}: HoverParams): Promise<Hover | null> => {
-    return hover(documents.get(textDocument.uri)!, position);
+    return hover(documents.get(textDocument.uri)!, position, {
+      descriptionProvider: descriptionProvider(sessionToken, cache)
+    });
   });
 
   connection.onRequest("workspace/executeCommand", (params: ExecuteCommandParams) => {

actions-languageserver/src/description-provider.ts

@@ -0,0 +1,26 @@
+import {DescriptionProvider} from "@github/actions-languageservice/hover";
+import {Octokit} from "@octokit/rest";
+import {TTLCache} from "./utils/cache";
+import {getActionInputDescription} from "./description-providers/action-input";
+
+export function descriptionProvider(sessionToken: string | undefined, cache: TTLCache): DescriptionProvider {
+  const octokit =
+    sessionToken &&
+    new Octokit({
+      auth: sessionToken
+    });
+
+  const getDescription: DescriptionProvider["getDescription"] = async (context, token, path) => {
+    if (!octokit) {
+      return undefined;
+    }
+    const parent = path[path.length - 1];
+    if (context.step && parent.definition?.key === "step-with") {
+      return await getActionInputDescription(octokit, cache, context.step, token);
+    }
+  };
+
+  return {
+    getDescription
+  };
+}

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

@@ -0,0 +1,35 @@
+import {parseActionReference} from "@github/actions-languageservice/action";
+import {isString} from "@github/actions-workflow-parser";
+import {isActionStep} from "@github/actions-workflow-parser/model/type-guards";
+import {Step} from "@github/actions-workflow-parser/model/workflow-template";
+import {TemplateToken} from "@github/actions-workflow-parser/templates/tokens/template-token";
+import {Octokit} from "@octokit/rest";
+import {fetchActionMetadata} from "../utils/action-metadata";
+import {TTLCache} from "../utils/cache";
+
+export async function getActionInputDescription(
+  client: Octokit,
+  cache: TTLCache,
+  step: Step,
+  token: TemplateToken
+): Promise<string | undefined> {
+  if (!isActionStep(step)) {
+    return undefined;
+  }
+  const action = parseActionReference(step.uses.value);
+  if (!action) {
+    return undefined;
+  }
+
+  const inputName = isString(token) && token.value;
+  if (!inputName) {
+    return undefined;
+  }
+
+  const metadata = await fetchActionMetadata(client, cache, action);
+  if (!metadata?.inputs) {
+    return undefined;
+  }
+
+  return metadata.inputs[inputName]?.description;
+}

actions-languageservice/src/hover.test.ts

@@ -1,6 +1,25 @@
-import {hover} from "./hover";
+import {isString} from "@github/actions-workflow-parser/.";
+import {StringToken} from "@github/actions-workflow-parser/templates/tokens/string-token";
+import {DescriptionProvider, hover, HoverConfig} from "./hover";
 import {getPositionFromCursor} from "./test-utils/cursor-position";
 
+function testHoverConfig(tokenValue: string, tokenKey: string, description?: string) {
+  return {
+    descriptionProvider: {
+      getDescription: async (_, token, __) => {
+        if (!isString(token)) {
+          throw new Error("Test provider only supports string tokens");
+        }
+
+        expect((token as StringToken).value).toEqual(tokenValue);
+        expect(token.definition!.key).toEqual(tokenKey);
+
+        return description;
+      }
+    } satisfies DescriptionProvider
+  } satisfies HoverConfig
+}
+
 describe("hover", () => {
   it("on a key", async () => {
     const input = `o|n: push
@@ -77,3 +96,37 @@ jobs:
     expect(result?.contents).toEqual("Runs your workflow when you push a commit or tag.");
   });
 });
+
+describe("hover with description provider", () => {
+  it("uses the description provider", async () => {
+    const input = `
+on: push
+jobs:
+  build:
+    runs-on: [self-hosted]
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          ref|: main
+`;
+
+    const result = await hover(...getPositionFromCursor(input), testHoverConfig("ref", "string", "The branch, tag or SHA to checkout."));
+    expect(result).not.toBeUndefined();
+    expect(result?.contents).toEqual("The branch, tag or SHA to checkout.");
+  });
+
+  it("falls back to the token description", async () => {
+    const input = `
+on: push
+jobs:
+  build:
+    runs-on: [self-hosted]
+    steps:
+      - uses|: actions/checkout@v2
+`;
+
+    const result = await hover(...getPositionFromCursor(input), testHoverConfig("uses", "non-empty-string", undefined));
+    expect(result).not.toBeUndefined();
+    expect(result?.contents).toEqual("Selects an action to run as part of a step in your job. An action is a reusable unit of code. You can use an action defined in the same repository as the workflow, a public repository, or in a published Docker container image.");
+  });
+});

actions-languageservice/src/hover.ts

@@ -1,37 +1,39 @@
-import {parseWorkflow} from "@github/actions-workflow-parser";
+import {convertWorkflowTemplate, parseWorkflow, ParseWorkflowResult} from "@github/actions-workflow-parser";
+import {ErrorPolicy} from "@github/actions-workflow-parser/model/convert";
 import {TemplateToken} from "@github/actions-workflow-parser/templates/tokens/template-token";
 import {File} from "@github/actions-workflow-parser/workflows/file";
 import {Position, TextDocument} from "vscode-languageserver-textdocument";
 import {Hover} from "vscode-languageserver-types";
+import {getWorkflowContext, WorkflowContext} from "./context/workflow-context";
 import {info} from "./log";
 import {nullTrace} from "./nulltrace";
 import {findToken} from "./utils/find-token";
 import {mapRange} from "./utils/range";
 
+export type DescriptionProvider = {
+  getDescription(context: WorkflowContext, token: TemplateToken, path: TemplateToken[]): Promise<string | undefined>;
+};
+
+export type HoverConfig = {
+  descriptionProvider?: DescriptionProvider;
+};
+
 // Render value description and Context when hovering over a key in a MappingToken
-export async function hover(document: TextDocument, position: Position): Promise<Hover | null> {
+export async function hover(document: TextDocument, position: Position, config?: HoverConfig): Promise<Hover | null> {
   const file: File = {
     name: document.uri,
     content: document.getText()
   };
   const result = parseWorkflow(file.name, [file], nullTrace);
 
-  const {token} = findToken(position, result.value);
+  const {token, path} = findToken(position, result.value);
-
+  if (!token?.definition) {
-  if (result.value && token) {
-    return getHover(token);
-  }
     return null;
   }
 
-function getHover(token: TemplateToken): Hover | null {
-  if (token.definition) {
   info(`Calculating hover for token with definition ${token.definition.key}`);
 
-    let description = "";
+  let description = await getDescription(document, config, result, token, path);
-    if (token.description) {
-      description = token.description;
-    }
 
   if (token.definition.evaluatorContext.length > 0) {
     // Only add padding if there is a description
@@ -43,7 +45,23 @@ function getHover(token: TemplateToken): Hover | null {
   return {
     contents: description,
     range: mapRange(token.range)
-    } as Hover;
+  } satisfies Hover;
 }
-  return null;
+
+async function getDescription(
+  document: TextDocument,
+  config: HoverConfig | undefined,
+  result: ParseWorkflowResult | undefined,
+  token: TemplateToken,
+  path: TemplateToken[]
+) {
+  const defaultDescription = token.description || "";
+  if (!result?.value || !config?.descriptionProvider) {
+    return defaultDescription;
+  }
+
+  const template = convertWorkflowTemplate(result.context, result.value, ErrorPolicy.TryConversion);
+  const workflowContext = getWorkflowContext(document.uri, template, path);
+  const description = await config.descriptionProvider.getDescription(workflowContext, token, path);
+  return description || defaultDescription;
 }

actions-languageservice/src/value-providers/config.ts

@@ -4,7 +4,7 @@ export interface Value {
   /** Label of this value */
   label: string;
 
-  /** Optional description to show when auto-completing or hovering */
+  /** Optional description to show when auto-completing */
   description?: string;
 
   /** Whether this value is deprecated */