avoid-implementation-in-mocks

v1.36.0

warning

effort: 2m

pro+

Warns when a class that extends Mock has overridden members.

Instead of adding implementation to mock classes, try specifying expected values via when. Alternatively, consider using Fake instead of Mock.

Example

❌ Bad:

class SomeClass extends Mock implements Other {
  // LINT: Classes that extend Mock should not have any overridden members.
  //  Try moving the implementation to when or use Fake instead.
  @override
  String getResult() => 'result';
}

✅ Good:

void main() {
  test('some test', () {
    final mock = SomeClass();

    when(() => mock.getResult()).thenReturn('result');
  });
}

class SomeClass extends Mock implements Other {}

Related Rules

• pass-mock-object