# Testing Setup Summary

## ✅ What We've Created

### 1. Test Files
- ✅ `tests/unit/utils/highlightUtils.test.ts` - 150+ lines, 30+ tests
- ✅ `tests/unit/utils/copyToClipboard.test.ts` - 80+ lines, 7 tests
- ✅ `tests/unit/components/HighlightCompo.test.ts` - 350+ lines, 40+ tests
- ✅ `tests/unit/components/ExampleWrapper.test.ts` - 280+ lines, 30+ tests

### 2. Configuration Files
- ✅ Updated `vite.config.ts` with test configuration and coverage settings
- ✅ Updated `package.json` with improved test scripts
- ✅ Already had `vitest-setup-client.ts` with mocks

### 3. CI/CD
- ✅ `.github/workflows/ci.yml` - Complete GitHub Actions workflow
  - Runs tests on Node 20.x and 22.x
  - Includes type checking, linting, unit tests, build, and E2E tests
  - Uploads coverage to Codecov
  - Runs on push and pull requests

### 4. Documentation
- ✅ `tests/README.md` - Test directory documentation
- ✅ `TESTING.md` - Comprehensive testing guide
- ✅ Updated main `README.md` with badges and testing section

## 📊 Test Coverage

### Utils
| File | Tests | Coverage Focus |
|------|-------|----------------|
| `highlightUtils.test.ts` | 30+ | All utility functions, edge cases |
| `copyToClipboard.test.ts` | 7 | Clipboard API, error handling |

### Components
| File | Tests | Coverage Focus |
|------|-------|----------------|
| `HighlightCompo.test.ts` | 40+ | Copy, expand/collapse, rendering, languages |
| `ExampleWrapper.test.ts` | 30+ | Component/code rendering, props, layout |

## 🚀 Available Commands

```bash
# Run all tests (CI mode)
pnpm test

# Run tests in watch mode (development)
pnpm test:watch

# Run with coverage report
pnpm test:coverage

# Open interactive test UI
pnpm test:ui

# Run only unit tests
pnpm test:unit

# Run E2E tests
pnpm test:e2e
```

## 🎯 Key Features

### Test Infrastructure
- ✅ **Vitest** - Fast, modern test runner
- ✅ **@testing-library/svelte** - Component testing utilities
- ✅ **Coverage reporting** - V8 provider with HTML reports
- ✅ **CI/CD integration** - GitHub Actions workflow
- ✅ **Multiple Node versions** - Test on 20.x and 22.x

### Mocking
- ✅ **ResizeObserver** - Globally mocked in setup
- ✅ **Clipboard API** - Mocked per test
- ✅ **Timers** - Fake timers for time-dependent tests
- ✅ **Window.matchMedia** - For responsive design tests

### Test Quality
- ✅ **Descriptive names** - Clear test descriptions
- ✅ **Edge case coverage** - Empty strings, null, undefined, errors
- ✅ **Behavior testing** - Focus on user-facing behavior
- ✅ **Isolation** - Each test is independent

## 📝 What Each Test File Covers

### highlightUtils.test.ts
- ✅ Constants validation
- ✅ Line highlighting (individual lines, ranges, combinations)
- ✅ Line number width calculation
- ✅ HTML escaping (all special characters)
- ✅ Library import replacement ($lib → custom name)
- ✅ Error handling and edge cases

### copyToClipboard.test.ts
- ✅ Successful copy operation
- ✅ Clipboard API errors
- ✅ Missing clipboard API
- ✅ Multi-line text
- ✅ Empty strings
- ✅ Special characters

### HighlightCompo.test.ts
- ✅ Basic rendering (code, empty, warnings)
- ✅ Copy functionality (button, success, error, timeout)
- ✅ Expand/collapse (show button, toggle, keep visible)
- ✅ Language support (JS, TS, JSON, YAML, Svelte, unknown)
- ✅ Library replacement
- ✅ Additional props (langtag, numberLine, highlightedLines)
- ✅ Edge cases (long code, special chars, empty)

### ExampleWrapper.test.ts
- ✅ Component + code rendering
- ✅ Component only / code only
- ✅ Name-based loading from objects
- ✅ Custom styling (class, innerClass, codeClass)
- ✅ Language prop handling
- ✅ HighlightCompo integration (showCopy, replaceLib)
- ✅ Edge cases (null, undefined, empty)
- ✅ Layout structure and hierarchy
- ✅ Prop priority (direct vs name lookup)

## 🔧 CI/CD Workflow

The GitHub Actions workflow (`ci.yml`) includes:

1. **Test Job** (Matrix: Node 20.x, 22.x)
   - Checkout code
   - Install dependencies
   - Type checking (`pnpm check`)
   - Linting (`pnpm lint`)
   - Unit tests (`pnpm test:unit`)
   - Coverage upload (Node 22.x only)

2. **Build Job**
   - Build library (`pnpm build`)
   - Package validation (`pnpm package`)

3. **E2E Job**
   - Install Playwright
   - Run E2E tests (`pnpm test:e2e`)
   - Upload results on failure

## 📈 Coverage Goals

| Category | Current Target | Notes |
|----------|---------------|-------|
| Utilities | 80%+ | High coverage for pure functions |
| Components | 70%+ | Focus on critical user paths |
| Critical Paths | 100% | Copy, expand/collapse, error handling |

## 🎓 Best Practices Implemented

1. ✅ **AAA Pattern** - Arrange, Act, Assert
2. ✅ **Descriptive Tests** - Clear "should..." descriptions
3. ✅ **Test Isolation** - No test interdependence
4. ✅ **Edge Cases** - Error conditions, null/undefined, boundaries
5. ✅ **Behavior Over Implementation** - Test what users see/do
6. ✅ **Proper Mocking** - Clean mocks with cleanup
7. ✅ **Async Handling** - Proper async/await and waitFor
8. ✅ **Type Safety** - TypeScript throughout

## 📚 Documentation

All testing aspects are documented:
- ✅ Test directory README with structure and commands
- ✅ Comprehensive TESTING.md guide
- ✅ Examples for writing tests
- ✅ Troubleshooting common issues
- ✅ CI/CD configuration explained
- ✅ Contributing guidelines

## 🚦 Next Steps

To use this testing setup:

1. **Run tests locally**:
   ```bash
   pnpm test
   ```

2. **Check coverage**:
   ```bash
   pnpm test:coverage
   open coverage/index.html
   ```

3. **Enable GitHub Actions**:
   - Push to your repository
   - GitHub Actions will run automatically

4. **Optional: Add Codecov**:
   - Sign up at codecov.io
   - Add `CODECOV_TOKEN` to GitHub secrets
   - Coverage reports will be uploaded automatically

5. **Write more tests**:
   - Follow patterns in existing tests
   - See TESTING.md for guidelines
   - Add tests for new features

## 🎉 Summary

You now have a **complete, production-ready testing infrastructure** with:
- 107+ comprehensive tests
- Multiple test categories (utils, components)
- Full CI/CD pipeline
- Coverage reporting
- Excellent documentation
- Best practices implemented

Your library is now much more maintainable, reliable, and contributor-friendly! 🚀
