# Testing

Use when writing or reviewing Flutter/Dart tests (unit, widget, golden), fixing flaky...

- Repository: https://github.com/evanca/flutter-ai-rules (668 stars)
- Category: Testing
- License: MIT
- Last updated: 2026-10-30
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add evanca/flutter-ai-rules --skill testing -g -a claude-code -y`
Codex: `npx skills add evanca/flutter-ai-rules --skill testing -g -a codex -y`
Cursor: `npx skills add evanca/flutter-ai-rules --skill testing -g -a cursor -y`
Gemini CLI: `npx skills add evanca/flutter-ai-rules --skill testing -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add evanca/flutter-ai-rules`

## Description

Use when writing or reviewing Flutter/Dart tests (unit, widget, golden), fixing flaky tests, adding coverage, or choosing between unit and widget tests.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Testing Skill

Write effective, meaningful Flutter and Dart tests that catch real regressions.

## When to Use

Use this skill when:

* Writing unit tests for business logic, repositories, or utility classes.
* Writing widget tests for UI components.
* Reviewing existing tests for correctness and coverage.
* Fixing flaky or false-positive tests.
* Deciding between unit tests, widget tests, and integration tests.

---

## 1. Test Validity

Before writing or accepting a test, ask:

> **"Can this test actually fail if the real code is broken?"**

- Avoid tests that only confirm mocked/fake behavior without exercising real logic.
- Avoid tests that confirm behavior guaranteed by the language or standard library.
- Every test must be capable of catching a real regression.

```dart
// BAD, tests the mock, not real logic
test('should return user', () {
  when(() => repo.getUser()).thenReturn(fakeUser);
  expect(repo.getUser(), fakeUser); // Only proves the mock works
});

// GOOD, tests the cubit's state transitions driven by the mock
blocTest<UserCubit, UserState>(
  'should emit loaded state when getUser succeeds',
  build: () {
    when(() => repo.getUser()).thenAnswer((_) async => fakeUser);
    return UserCubit(repo);
  },
  act: (cubit) => cubit.fetchUser(),
  expect: () => [
    const UserState(status: UserStatus.loading),
    UserState(status: UserStatus.loaded, user: fakeUser),
  ],
);
```

---

## 2. Structure

Always use `group()` in test files. Name the group after the **class under test**:

```dart
group('Counter', () {
  late Counter counter;

  setUp(() {
    counter = Counter();
  });

  test('value should start at 0', () {
    expect(counter.value, 0);
  });

  test('should increment value by 1', () {
    counter.increment();
    expect(counter.value, 1);
  });
});
```

The rest: https://github.com/evanca/flutter-ai-rules/blob/HEAD/skills/testing/SKILL.md