[seyedmostafahasani]

Summary:

PushNotificationIOS.addEventListener stores its subscription in _notifHandlers, keyed by event type, without checking whether one already exists. Calling it twice for the same type overwrites the first subscription in the map, so removeEventListener can only remove the second one. The first listener stays registered on the emitter, keeps its handler (and everything the handler closes over) alive, and keeps firing.

This change removes any previous subscription for the type before registering the new one, so at most one listener per type is ever registered and removeEventListener always cleans it up. The behavior change is that a second addEventListener for the same type now replaces the earlier handler instead of leaving it active and un-removable.

Changelog:

[IOS] [FIXED] - PushNotificationIOS.addEventListener no longer leaks the previous listener when called again for the same event type

Test Plan:

Added Libraries/PushNotificationIOS/__tests__/PushNotificationIOS-test.js, covering removal, adding the same type twice, and that only the latest handler is invoked.

• yarn jest packages/react-native/Libraries/PushNotificationIOS: 3 passed
• With the fix reverted, the double-add and latest-handler tests fail (2 failed, 1 passed), so the tests catch the leak
• yarn eslint --max-warnings 0 and yarn prettier --check on the changed files: clean

Not run: yarn flow-check and the native/iOS builds.