Fix removeAllListeners

source/event-emitter.ts

@@ -133,8 +133,8 @@ export class EventEmitter<T extends EventMap> {
             listeners.delete(entry);
         });
 
-        // If no listener was provided, remove the listeners set from the listeners map.
-        if (!listener) {
+        // If no listener was provided and no listeners are left for the event type, remove the listeners set from the listeners map.
+        if (!listener || this.#listeners.get(type)?.size === 0) {
             this.#listeners.delete(type);
         }
     }
@@ -169,7 +169,11 @@ export class EventEmitter<T extends EventMap> {
      * Remove all listeners.
      */
     removeAllListeners(): void {
-        this.#listeners.clear();
+        for (const [ type, listeners ] of this.#listeners.entries()) {
+            listeners.forEach((entry) => {
+                this.off(type, entry.listener);
+            });
+        }
     }
 
     /**

test/event-emitter.test.ts

@@ -305,6 +305,31 @@ const testEventEmitterRemoveAllListeners = (): void => {
     expect(countListener).not.toHaveBeenCalled();
 };
 
+/**
+ * Tests that removeAllListeners() cancels a pending debounced callback.
+ */
+const testEventEmitterRemoveAllListenersCancelsPendingDebouncedCallback = async (): Promise<void> => {
+    vi.useFakeTimers();
+
+    try {
+        const emitter = new EventEmitter<TestEvents>();
+        const listener = vi.fn();
+
+        // Arm a debounce timer, then clear every listener before it expires.
+        emitter.on('message', listener, 100);
+        emitter.emit('message', 'should not arrive');
+        emitter.removeAllListeners();
+
+        await vi.advanceTimersByTimeAsync(100);
+
+        // Cleared listeners must not receive delayed debounced delivery.
+        expect(listener).not.toHaveBeenCalled();
+    } finally {
+        vi.useRealTimers();
+        vi.restoreAllMocks();
+    }
+};
+
 /**
  * Tests that waitFor() resolves when a matching event is emitted.
  */
@@ -658,6 +683,10 @@ const runTests = async (): Promise<void> => {
         testEventEmitterOffCancelsPendingDebouncedCallback,
     );
     test('EventEmitter: removes all listeners when removeAllListeners is called', testEventEmitterRemoveAllListeners);
+    test(
+        'EventEmitter: cancels a pending debounced callback when removeAllListeners is called',
+        testEventEmitterRemoveAllListenersCancelsPendingDebouncedCallback,
+    );
     test('EventEmitter: resolves waitFor when a matching event is emitted', testEventEmitterWaitForResolvesOnMatch);
     test('EventEmitter: ignores non-matching events while waiting with waitFor', testEventEmitterWaitForIgnoresNonMatchingEvents);
     test('EventEmitter: rejects waitFor when the timeout is reached', testEventEmitterWaitForRejectsOnTimeout);