test-strategy

# Test Strategy Skill

Patterns for planning and organizing test suites.

## Testing Pyramid

```
        ┌─────────┐
        │   E2E   │  Few - Slow, Expensive
        ├─────────┤
        │  Integ  │  Some - Medium
        ├─────────┤
        │  Unit   │  Many - Fast, Cheap
        └─────────┘
```

### Recommended Ratios

- **Unit Tests**: 70% - Fast, isolated, cheap
- **Integration Tests**: 20% - API and service integration
- **E2E Tests**: 10% - Critical user flows only

## Test Organization

### By Feature

```
tests/
├── auth/
│   ├── login.test.ts
│   ├── logout.test.ts
│   ├── register.test.ts
│   └── password-reset.test.ts
├── users/
│   ├── create-user.test.ts
│   ├── update-user.test.ts
│   └── delete-user.test.ts
└── orders/
    ├── create-order.test.ts
    └── order-flow.e2e.ts
```

### By Type

```
tests/
├── unit/
│   ├── services/
│   ├── utils/
│   └── models/
├── integration/
│   ├── api/
│   └── database/
└── e2e/
    ├── flows/
    └── pages/
```

## What to Test

### Always Test

- Public API methods
- Business logic and calculations
- Error handling and edge cases
- Security-sensitive operations
- Data validation
- State transitions

### Consider Testing

- Complex private methods
- Performance-critical code
- Integration points
- Configuration loading

### Avoid Testing

- Third-party library internals
- Simple getters/setters
- Framework code
- Auto-generated code

## Test Prioritization

### P0 - Critical Path

Tests that must never fail:

- Authentication/authorization
- Payment processing
- Core business workflows
- Data integrity operations

### P1 - High Priority

Tests for important features:

- CRUD operations
- Search and filtering
- Notifications
- User preferences

### P2 - Normal Priority

Tests for auxiliary features:

- UI customization
- Report generation
- Export/import

## Test Naming

### Pattern

```typescript
// should [expected behavior] when [condition]
it('should return empty array when no users exist')
it('should throw V