test: use fake timers to skip sleeps

Author: buger

tests/e2e/pr-detection-e2e.test.ts

@@ -775,6 +775,7 @@ describe('PR Detection E2E Tests', () => {
     });
 
     test('should timeout on slow API responses', async () => {
+      jest.useFakeTimers();
       let slowResponseTimer: NodeJS.Timeout | undefined;
       let raceTimeout: NodeJS.Timeout | undefined;
 
@@ -793,18 +794,20 @@ describe('PR Detection E2E Tests', () => {
       // For now, we'll just verify it doesn't hang
       const startTime = Date.now();
 
+      const race = Promise.race([
+        prDetector.detectPRNumber(
+          PUSH_EVENT_TO_FEATURE_BRANCH as GitHubEventContext,
+          MOCK_REPO_INFO.owner,
+          MOCK_REPO_INFO.name
+        ),
+        new Promise((_, reject) => {
+          raceTimeout = setTimeout(() => reject(new Error('Test timeout')), 1000);
+        }),
+      ]);
+      const raceExpectation = expect(race).rejects.toThrow('Test timeout');
       try {
-        await Promise.race([
-          prDetector.detectPRNumber(
-            PUSH_EVENT_TO_FEATURE_BRANCH as GitHubEventContext,
-            MOCK_REPO_INFO.owner,
-            MOCK_REPO_INFO.name
-          ),
-          new Promise((_, reject) => {
-            raceTimeout = setTimeout(() => reject(new Error('Test timeout')), 1000);
-          }),
-        ]);
-      } catch {
+        await jest.advanceTimersByTimeAsync(1000);
+        await raceExpectation;
         const elapsed = Date.now() - startTime;
         expect(elapsed).toBeLessThan(2000); // Should fail fast
       } finally {
@@ -814,6 +817,7 @@ describe('PR Detection E2E Tests', () => {
         if (raceTimeout) {
           clearTimeout(raceTimeout);
         }
+        jest.useRealTimers();
       }
     });
   });

tests/unit/env-resolver.test.ts

@@ -142,11 +142,12 @@ describe('EnvironmentResolver', () => {
     });
 
     test('should handle async callbacks', async () => {
+      jest.useFakeTimers();
       const envConfig = {
         ASYNC_VAR: '${{ env.TEST_API_KEY }}',
       };
 
-      const result = await EnvironmentResolver.withTemporaryEnv(envConfig, async () => {
+      const resultPromise = EnvironmentResolver.withTemporaryEnv(envConfig, async () => {
         expect(process.env.ASYNC_VAR).toBe('test-api-key-123');
 
         // Simulate async work
@@ -156,8 +157,12 @@ describe('EnvironmentResolver', () => {
         return 'async-result';
       });
 
+      await jest.advanceTimersByTimeAsync(10);
+      const result = await resultPromise;
+
       expect(result).toBe('async-result');
       expect(process.env.ASYNC_VAR).toBeUndefined();
+      jest.useRealTimers();
     });
 
     test('should restore environment even if callback throws', () => {

tests/unit/github-frontend-concurrency.test.ts

@@ -8,6 +8,7 @@ describe('GitHubFrontend Concurrency', () => {
   let updateCalls: Array<{ group: string; timestamp: number }> = [];
 
   beforeEach(() => {
+    jest.useFakeTimers();
     updateCalls = [];
 
     // Mock CommentManager
@@ -66,6 +67,10 @@ describe('GitHubFrontend Concurrency', () => {
     frontend.minUpdateDelayMs = 100;
   });
 
+  afterEach(() => {
+    jest.useRealTimers();
+  });
+
   it('should serialize concurrent updates to the same group', async () => {
     // Access private method via reflection for testing
     const updateMethod = (frontend as any).updateGroupedComment.bind(frontend);
@@ -79,7 +84,9 @@ describe('GitHubFrontend Concurrency', () => {
       updateMethod(mockContext, mockComments, 'test-group'),
     ];
 
-    await Promise.all(updates);
+    const updatesDone = Promise.all(updates);
+    await jest.runAllTimersAsync();
+    await updatesDone;
 
     const totalTime = Date.now() - startTime;
 
@@ -107,10 +114,12 @@ describe('GitHubFrontend Concurrency', () => {
     const startTime = Date.now();
 
     // Simulate concurrent updates to different groups
-    await Promise.all([
+    const updatesDone = Promise.all([
       updateMethod(mockContext, mockComments, 'group-1'),
       updateMethod(mockContext, mockComments, 'group-2'),
     ]);
+    await jest.runAllTimersAsync();
+    await updatesDone;
 
     const totalTime = Date.now() - startTime;
 
@@ -129,10 +138,14 @@ describe('GitHubFrontend Concurrency', () => {
     const startTime = Date.now();
 
     // Sequential updates should respect minUpdateDelayMs
-    await updateMethod(mockContext, mockComments, 'test-group');
+    const firstUpdate = updateMethod(mockContext, mockComments, 'test-group');
+    await jest.runAllTimersAsync();
+    await firstUpdate;
     const firstUpdateTime = Date.now() - startTime;
 
-    await updateMethod(mockContext, mockComments, 'test-group');
+    const secondUpdate = updateMethod(mockContext, mockComments, 'test-group');
+    await jest.runAllTimersAsync();
+    await secondUpdate;
     const secondUpdateTime = Date.now() - startTime;
 
     const timeBetweenUpdates = secondUpdateTime - firstUpdateTime;