refactor(github-actions): extract shared labeling functionality into base class

Extracts the common logic used by IssueLabeling and PullRequestLabeling into a
shared Labeling base class. This simplifies code duplication and unifies how
labels are added, removed, and authentication is handled with Octokit.

Author: josephperrott

github-actions/labeling/issue/BUILD.bazel

@@ -17,6 +17,7 @@ ts_project(
         "//github-actions/labeling:node_modules/@octokit/openapi-types",
         "//github-actions/labeling:node_modules/@octokit/rest",
         "//github-actions/labeling:node_modules/@types/node",
+        "//github-actions/labeling/shared",
         "//ng-dev/pr/common/labels",
     ],
 )
@@ -28,7 +29,6 @@ ts_project(
     tsconfig = "//github-actions:tsconfig_test",
     deps = [
         ":lib",
-
         "//github-actions:utils",
         "//github-actions/labeling:node_modules/@actions/core",
         "//github-actions/labeling:node_modules/@actions/github",

github-actions/labeling/issue/lib/issue-labeling.spec.ts

@@ -1,74 +1,48 @@
 import {Octokit} from '@octokit/rest';
 import * as core from '@actions/core';
-import {context} from '@actions/github';
-import {GoogleGenAI} from '@google/genai';
-import {IssueLabeling} from './issue-labeling.js';
+import {IssueLabeling as _IssueLabeling} from './issue-labeling.js';
 
-class TestableIssueLabeling extends IssueLabeling {
-  public constructor(git: Octokit, coreService: typeof core) {
-    super(git, coreService);
+class IssueLabeling extends _IssueLabeling {
+  setGit(git: any) {
+    this.git = git;
   }
 }
 
 describe('IssueLabeling', () => {
-  let mockGit: {
-    paginate: jasmine.Spy;
-    issues: {
-      listLabelsForRepo: jasmine.Spy;
-      addLabels: jasmine.Spy;
-      get: jasmine.Spy;
-    };
-  };
+  let mockGit: jasmine.SpyObj<Octokit>;
   let mockAI: any;
-  let mockCore: jasmine.SpyObj<typeof core>;
   let issueLabeling: IssueLabeling;
+  let getIssue: jasmine.Spy;
 
   beforeEach(() => {
-    mockGit = {
-      paginate: jasmine.createSpy('paginate'),
-      issues: {
-        listLabelsForRepo: jasmine.createSpy('listLabelsForRepo'),
-        addLabels: jasmine.createSpy('addLabels'),
-        get: jasmine.createSpy('get'),
-      },
-    };
+    mockGit = jasmine.createSpyObj('Octokit', ['paginate', 'issues', 'pulls']);
+    mockGit.issues = jasmine.createSpyObj('issues', ['addLabels', 'get']);
+
+    // Mock paginate to return the result of the promise if it's a list, or just execute the callback
+    (mockGit.paginate as jasmine.Spy).and.callFake((fn: any, args: any) => {
+      if (fn === mockGit.issues.listLabelsOnIssue) {
+        return Promise.resolve([{name: 'area: core'}, {name: 'area: router'}, {name: 'bug'}]);
+      }
+      return Promise.resolve([]);
+    });
 
-    mockGit.issues.addLabels.and.returnValue(Promise.resolve({}));
-    mockGit.issues.get.and.returnValue(
-      Promise.resolve({
-        data: {
-          title: 'Tough Issue',
-          body: 'Complex Body',
-          labels: [],
-        },
-      }),
-    );
-    mockGit.paginate.and.resolveTo([{name: 'area: core'}, {name: 'area: router'}, {name: 'bug'}]);
+    (mockGit.issues.addLabels as unknown as jasmine.Spy).and.returnValue(Promise.resolve({}));
+    getIssue = mockGit.issues.get as unknown as jasmine.Spy;
+    getIssue.and.resolveTo({
+      data: {
+        title: 'Tough Issue',
+        body: 'Complex Body',
+        labels: [],
+      },
+    });
 
     mockAI = {
       models: jasmine.createSpyObj('models', ['generateContent']),
     };
-    mockCore = jasmine.createSpyObj<typeof core>('core', [
-      'getInput',
-      'info',
-      'error',
-      'warning',
-      'debug',
-      'setFailed',
-    ]);
-    mockCore.getInput.and.returnValue('mock-ai-key');
-    mockCore.error.and.callFake(console.error);
-    mockCore.info.and.callFake(console.info);
-    mockCore.warning.and.callFake(console.warn);
-    mockCore.debug.and.callFake(console.debug);
-    mockCore.setFailed.and.callFake(console.error);
-
-
-    // We must cast the mock to Octokit because the mock only implements the subset used by the class.
-    // This is standard for mocking large interfaces like Octokit.
-    issueLabeling = new TestableIssueLabeling(mockGit as unknown as Octokit, mockCore);
-
-    spyOn(issueLabeling, 'getGenerativeAI').and.returnValue(mockAI);
+
+    spyOn(IssueLabeling.prototype, 'getGenerativeAI').and.returnValue(mockAI);
+    issueLabeling = new IssueLabeling();
+    issueLabeling.setGit(mockGit as unknown as Octokit);
   });
 
   it('should initialize labels correctly', async () => {
@@ -85,6 +59,7 @@ describe('IssueLabeling', () => {
       }),
     );
 
+    await issueLabeling.initialize();
     await issueLabeling.run();
 
     expect(mockGit.issues.addLabels).toHaveBeenCalledWith(
@@ -101,6 +76,7 @@ describe('IssueLabeling', () => {
       }),
     );
 
+    await issueLabeling.initialize();
     await issueLabeling.run();
 
     expect(mockGit.issues.addLabels).not.toHaveBeenCalled();
@@ -113,28 +89,24 @@ describe('IssueLabeling', () => {
       }),
     );
 
+    await issueLabeling.initialize();
     await issueLabeling.run();
 
     expect(mockGit.issues.addLabels).not.toHaveBeenCalled();
   });
 
-  it('should initialize and run with manual instantiation check', () => {
-    expect(issueLabeling).toBeDefined();
-    expect(mockCore.getInput).not.toHaveBeenCalled(); // until run is called
-  });
-
   it('should skip labeling when issue already has an area label', async () => {
-    mockGit.issues.get.and.resolveTo({
+    getIssue.and.resolveTo({
       data: {
         title: 'Tough Issue',
         body: 'Complex Body',
         labels: [{name: 'area: core'}],
       },
     });
+    await issueLabeling.initialize();
 
     await issueLabeling.run();
 
     expect(mockGit.issues.addLabels).not.toHaveBeenCalled();
-    expect(mockCore.info).toHaveBeenCalledWith('Issue already has an area label. Skipping.');
   });
 });

github-actions/labeling/issue/lib/issue-labeling.ts

@@ -1,51 +1,27 @@
 import * as core from '@actions/core';
 import {context} from '@actions/github';
 import {GoogleGenAI} from '@google/genai';
-import {Octokit} from '@octokit/rest';
-import {ANGULAR_ROBOT, getAuthTokenFor, revokeActiveInstallationToken} from '../../../utils.js';
 import {components} from '@octokit/openapi-types';
 import {miscLabels} from '../../../../ng-dev/pr/common/labels/index.js';
+import {Labeling} from '../../shared/labeling.js';
 
-export class IssueLabeling {
-  static run = async () => {
-    const token = await getAuthTokenFor(ANGULAR_ROBOT);
-    const git = new Octokit({auth: token});
-    try {
-      const inst = new this(git, core);
-      await inst.run();
-    } finally {
-      await revokeActiveInstallationToken(git);
-    }
-  };
-
+export class IssueLabeling extends Labeling {
+  readonly type = 'Issue';
   /** Set of area labels available in the current repository. */
   repoAreaLabels = new Set<string>();
   /** The issue data fetched from Github. */
   issueData?: components['schemas']['issue'];
 
-  protected constructor(
-    private git: Octokit,
-    private coreService: typeof core,
-  ) {}
-
   async run() {
-    const {issue} = context;
-    if (!issue || !issue.number) {
-      this.coreService.info('No issue context found. Skipping.');
-      return;
-    }
-    this.coreService.info(`Issue #${issue.number}`);
-
-    // Initialize labels and issue data
-    await this.initialize();
+    core.info(`Updating labels for ${this.type} #${context.issue.number}`);
 
     // Determine if the issue already has an area label, if it does we can exit early.
     if (
       this.issueData?.labels.some((label) =>
         (typeof label === 'string' ? label : label.name)?.startsWith('area: '),
       )
     ) {
-      this.coreService.info('Issue already has an area label. Skipping.');
+      core.info('Issue already has an area label. Skipping.');
       return;
     }
 
@@ -77,38 +53,27 @@ If no area label applies, respond with "none".
       });
       const text = (response.text || '').trim();
 
-      this.coreService.info(`Gemini suggested label: ${text}`);
+      core.info(`Gemini suggested label: ${text}`);
 
       if (this.repoAreaLabels.has(text)) {
         await this.addLabel(text);
         await this.addLabel(miscLabels.GEMINI_TRIAGED.name);
       } else {
-        this.coreService.info(
+        core.info(
           `Generated label "${text}" is not in the list of valid area labels or is "ambiguous"/"none".`,
         );
       }
     } catch (e) {
-      this.coreService.error('Failed to generate content from Gemini.');
-      this.coreService.setFailed(e as Error);
+      core.error('Failed to generate content from Gemini.');
+      core.setFailed(e as Error);
     }
   }
 
   getGenerativeAI() {
-    const apiKey = this.coreService.getInput('google-generative-ai-key', {required: true});
+    const apiKey = core.getInput('google-generative-ai-key', {required: true});
     return new GoogleGenAI({apiKey});
   }
 
-  async addLabel(label: string) {
-    const {number: issue_number, owner, repo} = context.issue;
-    try {
-      await this.git.issues.addLabels({repo, owner, issue_number, labels: [label]});
-      this.coreService.info(`Added ${label} label to Issue #${issue_number}`);
-    } catch (err) {
-      this.coreService.error(`Failed to add ${label} label to Issue #${issue_number}`);
-      this.coreService.debug(err as string);
-    }
-  }
-
   async initialize() {
     const {owner, repo} = context.issue;
     await Promise.all([
@@ -123,15 +88,5 @@ If no area label applies, respond with "none".
         this.issueData = resp.data;
       }),
     ]);
-
-    if (this.repoAreaLabels.size === 0) {
-      this.coreService.warning('No area labels found in the repository.');
-      return;
-    }
-
-    if (!this.issueData) {
-      this.coreService.error('Failed to fetch issue data.');
-      return;
-    }
   }
 }