This skill should be used when writing or debugging Flutter widget tests that involve AnimationController, animateTo, animateBack, Future.delayed, pumpAndSettle, chained animations, or any async animation sequencing. Use this skill to avoid known pitfalls with animation controller status, timer-based delays in tests, and async animation chaining.
This skill documents hard-won lessons about testing Flutter animations. These pitfalls are non-obvious and cause test failures that are difficult to diagnose from error messages alone.
animateTo vs animateBack — Controller Status CorruptionanimateTo(target) always sets _direction = _AnimationDirection.forward
internally, regardless of whether the target is above or below the current
value. When the animation completes, Flutter sets the status based on