test(core): use fake timers in Queue unit tests to stop CI flakes (#6134)

The Queue tests measured real setTimeout wall-clock time and asserted
elapsed < 2 * threshold. On busy CI runners a 2400ms timer can take
longer than 4800ms to fire, failing the assertion intermittently (seen
in downstream validation runs). Switch to jest's modern fake timers so
elapsed is exactly the timeout delay: the tests are deterministic and
no longer spend ~5 seconds of real time waiting.

platform/core/src/utils/Queue.test.js

@@ -17,7 +17,21 @@ function timeout(delay) {
 
 const threshold = 2400;
 
+// Fake timers make these tests deterministic: with real timers the elapsed
+// assertions depend on wall-clock scheduling and flake on busy CI runners
+// (a 2400ms setTimeout can take more than 4800ms to fire under load).
+// jest's modern fake timers also mock Date.now, so advanceTimersByTime moves
+// the timers and the clock together and elapsed is exactly the timeout delay.
+
 describe('Queue', () => {
+  beforeEach(() => {
+    jest.useFakeTimers();
+  });
+
+  afterEach(() => {
+    jest.useRealTimers();
+  });
+
   // Todo: comment due to wrong implementation
   // it('should bind functions to the queue', async () => {
   //   const queue = new Queue(2);
@@ -38,14 +52,14 @@ describe('Queue', () => {
     const timer = queue.bind(mockedTimeout);
     const start = Date.now();
     const promise = timer(threshold).then(time => time - start);
-    try {
+    // The queue is full, so the second call rejects without waiting. Awaiting
-      await timer(threshold);
+    // the rejection also flushes the microtasks that register the first
-    } catch (e) {
+    // task's setTimeout, so it can be advanced below.
-      expect(Date.now() - start < threshold).toBe(true);
+    await expect(timer(threshold)).rejects.toThrow('Queue limit reached');
-      expect(e.message).toBe('Queue limit reached');
+    expect(Date.now() - start < threshold).toBe(true);
-    }
+    jest.advanceTimersByTime(threshold);
     const elapsed = await promise;
-    expect(elapsed >= threshold && elapsed < 2 * threshold).toBe(true);
+    expect(elapsed).toBe(threshold);
     expect(mockedTimeout).toHaveBeenCalledTimes(1);
   });
   it('should safely bind tasks to the queue', async () => {
@@ -62,8 +76,9 @@ describe('Queue', () => {
       1,
       expect.objectContaining({ message: 'Queue limit reached' })
     );
+    jest.advanceTimersByTime(threshold);
     const elapsed = await promise;
-    expect(elapsed >= threshold && elapsed < 2 * threshold).toBe(true);
+    expect(elapsed).toBe(threshold);
     expect(mockedTimeout).toHaveBeenCalledTimes(1);
   });
 });