A Timer is still pending even after the widget tree was disposed Flutter / Dart Origin: On your device Last updated 4 Nov 2026

Flutter test: A Timer is still pending even after the widget tree was disposed

A widget test finished while a Timer or delayed Future was still scheduled.

Exact message you may see A Timer is still pending even after the widget tree was disposedTimer is still pending after widget tree disposedpumpAndSettle timed outA Timer is still pending even after the widget tree was disposed. Test failed
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Seen on: Flutter

Meaning

Flutter tests fail if timers outlive the test. Cancel timers in dispose(), advance fake time with await tester.pump(duration) or pumpAndSettle, and avoid real delays. Libraries with periodic timers (animations, polling) need a mock or dispose.

Common causes

  • Timer/Future.delayed not cancelled in dispose()
  • Test ended before the timer fired
  • Periodic polling or retry timers
  • Animation looping forever (pumpAndSettle timeout)
  • Third-party plugin timers

⚡ Quick fix

  1. Cancel timers in dispose()
  2. Advance time: await tester.pump(const Duration(seconds: 2));
  3. Mock the timer-owning service in tests

Detailed fix by platform

Flutter

  1. In tests, replace delays with FakeAsync or inject a short duration

How to diagnose

  1. Timer — Where created?
  2. Dispose — Cancelled?
  3. Test — Time advanced?

🔧 Still not fixed?

Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:

Where this error sits

Origin: On your device. Errors that are often confused with or caused by this one (click to open):

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