Testing Flutter apps

Automated tests ensure an app performs correctly before publication while retaining velocity. Well-tested apps have many unit and widget tests tracked by code coverage, plus integration tests covering all important use cases. Unit tests verify a unit of logic under varied conditions, mocking external dependencies and avoiding disk I/O or screen rendering. Widget tests verify a widget's UI looks and interacts as expected, in an environment simpler than a full-blown UI system. Integration tests check a complete app or large part. Trade-offs: unit tests offer low confidence and maintenance cost, run quick, and have few dependencies; widget tests rank higher on confidence, cost, and dependencies while staying quick; integration tests rank highest on all three but run slow. Recipes cover Mockito and finders. Scope: Flutter. Reviewed October 4, 2026.