End-to-End Test Generation

I'll generate comprehensive E2E tests using Playwright for browser automation and testing.

Capabilities:

• Auto-detect frontend framework (React, Vue, Next.js, etc.)
• Generate Playwright test files with best practices
• Create page object models for maintainability
• Set up test infrastructure if missing

Token Optimization:

• ✅ Bash-based Playwright detection (minimal tokens)
• ✅ Grep to find routes/pages (200 tokens vs 3,000+ reading all files)
• ✅ Template-based test generation (no file reads for templates)
• ✅ Caching page/route discovery - saves 80% on reruns
• ✅ Early exit when Playwright not needed
• ✅ Incremental test generation (one page at a time)
• Expected tokens: 1,200-3,000 (vs. 3,000-5,000 unoptimized)
• Optimization status: ✅ Optimized (Phase 2 Batch 2, 2026-01-26)

Caching Behavior:

• Cache location: .claude/cache/e2e/routes.json
• Caches: Discovered routes/pages, framework detection
• Cache validity: Until route files change (checksum-based)
• Shared with: /playwright-automate, /test skills

Phase 1: Prerequisites Check

# Check if Playwright is installed
if [ -f "package.json" ]; then
    if grep -q "\"@playwright/test\"" package.json; then
        echo "✓ Playwright detected"
        PLAYWRIGHT_INSTALLED=true
    else
        echo "⚠️ Playwright not installed"
        PLAYWRIGHT_INSTALLED=false
    fi
else
    echo "❌ No package.json found"
    exit 1
fi

# Offer to install Playwright if missing
if [ "$PLAYWRIGHT_INSTALLED" = false ]; then
    echo ""
    echo "Playwright is required for E2E testing"
    read -p "Install Playwright? (yes/no): " install_pw

    if [ "$install_pw" = "yes" ]; then
        echo "Installing Playwright..."
        npm install --save-dev @playwright/test
        npx playwright install
        echo "✓ Playwright installed"
    else
        echo "Skipping installation. Install manually with:"
        echo "  npm install --save-dev @playwright/test"
        echo "  npx playwright install"
        exit 1
    fi
fi

Phase 2: Framework Detection

# Token-efficient framework detection
detect_framework() {
    if grep -q "\"next\"" package.json; then
        echo "nextjs"
    elif grep -q "\"react\"" package.json; then
        if [ -d "src/pages" ] || [ -d "pages" ]; then
            echo "react-pages"
        else
            echo "react-spa"
        fi
    elif grep -q "\"vue\"" package.json; then
        echo "vue"
    elif grep -q "\"@angular/core\"" package.json; then
        echo "angular"
    elif grep -q "\"svelte\"" package.json; then
        echo "svelte"
    else
        echo "generic"
    fi
}

FRAMEWORK=$(detect_framework)
echo "✓ Framework detected: $FRAMEWORK"

Phase 3: Page/Route Discovery

# Discover pages/routes efficiently with Grep
echo ""
echo "Discovering application pages..."

case $FRAMEWORK in
    nextjs)
        # Next.js App Router
        if [ -d "app" ]; then
            PAGES=$(find app -name "page.tsx" -o -name "page.jsx" -o -name "page.js" | head -10)
        # Next.js Pages Router
        elif [ -d "pages" ]; then
            PAGES=$(find pages -name "*.tsx" -o -name "*.jsx" -o -name "*.js" | grep -v "_app\|_document\|api" | head -10)
        fi
        ;;
    react-pages)
        PAGES=$(find src/pages -name "*.tsx" -o -name "*.jsx" | head -10)
        ;;
    react-spa)
        # Look for React Router routes
        ROUTES=$(grep -r "path=" src/ --include="*.tsx" --include="*.jsx" | head -10)
        ;;
    vue)
        PAGES=$(find src -name "*.vue" | head -10)
        ;;
esac

if [ -z "$PAGES" ]; then
    echo "⚠️ No pages found. Will generate generic test template."
    PAGE_COUNT=0
else
    PAGE_COUNT=$(echo "$PAGES" | wc -l)
    echo "✓ Found $PAGE_COUNT pages"
    echo ""
    echo "Sample pages:"
    echo "$PAGES" | head -5 | sed 's/^/  /'

    if [ $PAGE_COUNT -gt 5 ]; then
        echo "  ... and $((PAGE_COUNT - 5)) more"
    fi
fi

Phase 4: Test Generation

# Create E2E test directory
mkdir -p tests/e2e

echo ""
echo "Generating E2E tests..."

# Generate playwright config if missing
if [ ! -f "playwright.config.ts" ]; then
    cat > playwright.config.ts << 'EOF'
import { defineConfig, devices } from '@playwright/test';

export default defineConfig({
  testDir: './tests/e2e',
  fullyParallel: true,
  forbidOnly: !!process.env.CI,
  retries: process.env.CI ? 2 : 0,
  workers: process.env.CI ? 1 : undefined,
  reporter: 'html',
  use: {
    baseURL: 'http://localhost:3000',
    trace: 'on-first-retry',
  },

  projects: [
    {
      name: 'chromium',
      use: { ...devices['Desktop Chrome'] },
    },
    {
      name: 'firefox',
      use: { ...devices['Desktop Firefox'] },
    },
    {
      name: 'webkit',
      use: { ...devices['Desktop Safari'] },
    },
  ],

  webServer: {
    command: 'npm run dev',
    url: 'http://localhost:3000',
    reuseExistingServer: !process.env.CI,
  },
});
EOF
    echo "✓ Created playwright.config.ts"
fi

# Generate base test template
cat > tests/e2e/example.spec.ts << 'EOF'
import { test, expect } from '@playwright/test';

test.describe('Application E2E Tests', () => {
  test('should load homepage', async ({ page }) => {
    await page.goto('/');

    // Verify page loads
    await expect(page).toHaveTitle(/./);

    // Check for main content
    const mainContent = page.locator('main, #root, #app, [role="main"]');
    await expect(mainContent).toBeVisible();
  });

  test('should navigate between pages', async ({ page }) => {
    await page.goto('/');

    // Find and click a navigation link
    const navLink = page.locator('nav a, header a').first();
    await navLink.click();

    // Verify navigation occurred
    await page.waitForLoadState('networkidle');
    await expect(page.url()).not.toBe('http://localhost:3000/');
  });

  test('should be responsive', async ({ page }) => {
    // Test desktop view
    await page.setViewportSize({ width: 1920, height: 1080 });
    await page.goto('/');
    await expect(page.locator('body')).toBeVisible();

    // Test mobile view
    await page.setViewportSize({ width: 375, height: 667 });
    await expect(page.locator('body')).toBeVisible();
  });
});
EOF

echo "✓ Created tests/e2e/example.spec.ts"

# Generate page-specific tests if pages found
if [ $PAGE_COUNT -gt 0 ]; then
    # Generate test for first page as example
    FIRST_PAGE=$(echo "$PAGES" | head -1)
    PAGE_NAME=$(basename "$FIRST_PAGE" | sed 's/\.[^.]*$//')

    cat > "tests/e2e/${PAGE_NAME}.spec.ts" << EOF
import { test, expect } from '@playwright/test';

test.describe('${PAGE_NAME} Page', () => {
  test.beforeEach(async ({ page }) => {
    // Navigate to page before each test
    await page.goto('/${PAGE_NAME}');
  });

  test('should render page correctly', async ({ page }) => {
    // Verify page loads
    await page.waitForLoadState('networkidle');

    // Check for key elements
    // TODO: Update selectors based on your page structure
    const heading = page.locator('h1, h2').first();
    await expect(heading).toBeVisible();
  });

  test('should handle user interactions', async ({ page }) => {
    // TODO: Add interaction tests
    // Example: Click buttons, fill forms, etc.
  });

  test('should display correct content', async ({ page }) => {
    // TODO: Verify page content
    // Example: Check text, images, links
  });

  test('should handle errors gracefully', async ({ page }) => {
    // TODO: Test error scenarios
    // Example: Invalid input, network failures
  });
});
EOF

    echo "✓ Created tests/e2e/${PAGE_NAME}.spec.ts"
fi

Phase 5: Page Object Model (Optional but Recommended)

# Generate page object model example
mkdir -p tests/e2e/pages

cat > tests/e2e/pages/BasePage.ts << 'EOF'
import { Page } from '@playwright/test';

export class BasePage {
  constructor(protected page: Page) {}

  async goto(path: string) {
    await this.page.goto(path);
    await this.page.waitForLoadState('networkidle');
  }

  async waitForElement(selector: string) {
    await this.page.waitForSelector(selector);
  }

  async clickElement(selector: string) {
    await this.page.click(selector);
  }

  async typeIntoField(selector: string, text: string) {
    await this.page.fill(selector, text);
  }
}
EOF

echo "✓ Created tests/e2e/pages/BasePage.ts (Page Object Model base)"

cat > tests/e2e/pages/HomePage.ts << 'EOF'
import { Page } from '@playwright/test';
import { BasePage } from './BasePage';

export class HomePage extends BasePage {
  constructor(page: Page) {
    super(page);
  }

  async navigate() {
    await this.goto('/');
  }

  async getPageTitle() {
    return await this.page.title();
  }

  async clickNavLink(linkText: string) {
    await this.page.click(`nav a:has-text("${linkText}")`);
  }

  // Add more page-specific methods
}
EOF

echo "✓ Created tests/e2e/pages/HomePage.ts"

Phase 6: Test Scripts

# Update package.json with E2E test scripts
if [ -f "package.json" ]; then
    # Check if test:e2e script exists
    if ! grep -q "\"test:e2e\"" package.json; then
        echo ""
        echo "Add these scripts to package.json:"
        echo ""
        cat << 'EOF'
  "scripts": {
    "test:e2e": "playwright test",
    "test:e2e:headed": "playwright test --headed",
    "test:e2e:debug": "playwright test --debug",
    "test:e2e:ui": "playwright test --ui"
  }
EOF
    fi
fi

Running Your E2E Tests

echo ""
echo "=== E2E Test Setup Complete! ==="
echo ""
echo "📁 Test files created:"
echo "  - tests/e2e/example.spec.ts"
if [ $PAGE_COUNT -gt 0 ]; then
    echo "  - tests/e2e/${PAGE_NAME}.spec.ts"
fi
echo "  - tests/e2e/pages/BasePage.ts"
echo "  - tests/e2e/pages/HomePage.ts"
echo "  - playwright.config.ts"
echo ""
echo "🚀 Run tests:"
echo "  npm run test:e2e              # Run all tests"
echo "  npm run test:e2e:headed       # Run with browser visible"
echo "  npm run test:e2e:debug        # Run in debug mode"
echo "  npm run test:e2e:ui           # Run with Playwright UI"
echo ""
echo "📝 Next steps:"
echo "  1. Customize test selectors for your app"
echo "  2. Add more page-specific tests"
echo "  3. Implement page object models for complex pages"
echo "  4. Add to CI/CD pipeline with /ci-setup"

Best Practices

E2E Testing Tips:

• ✅ Use data-testid attributes for reliable selectors
• ✅ Test user workflows, not implementation details
• ✅ Keep tests independent (no shared state)
• ✅ Use page object models for maintainability
• ✅ Run tests in CI/CD pipeline

Anti-Patterns:

• ❌ Testing every possible scenario (focus on critical paths)
• ❌ Fragile selectors (CSS classes that change often)
• ❌ Long test chains (break into smaller tests)
• ❌ No waiting for async operations

Integration Points

• /ci-setup - Add E2E tests to CI pipeline
• /test - Run E2E tests alongside unit tests
• /deploy-validate - Run E2E tests before deployment

Credits: Playwright integration patterns based on community best practices and MCP Playwright server capabilities.

Token Optimization

This skill implements aggressive token optimization achieving 60% token reduction compared to naive implementation:

Token Budget:

• Current (Optimized): 1,200-3,000 tokens per invocation
• Previous (Unoptimized): 3,000-5,000 tokens per invocation
• Reduction: 60% (average)

Optimization Strategies Applied

1. Early Exit for Playwright Detection (saves 95%)

# Check if Playwright is installed before any other operations
if ! grep -q "\"@playwright/test\"" package.json 2>/dev/null; then
    echo "⚠️ Playwright not installed"
    echo "Install with: npm install --save-dev @playwright/test"
    exit 0  # Exit immediately, saves ~4,500 tokens
fi

# If Playwright is installed but user wants to skip
if [ "$SKIP_E2E" = "true" ]; then
    echo "✓ Skipping E2E test generation"
    exit 0  # Saves ~4,500 tokens
fi

Exit scenarios:

• Playwright not installed and user declines installation
• E2E tests not needed for current change
• Tests already exist and no changes to pages/components
• Skip flag explicitly set

2. Framework Detection Caching (saves 70% on cache hits)

CACHE_FILE=".claude/cache/e2e/framework-config.json"

if [ -f "$CACHE_FILE" ] && [ $(find "$CACHE_FILE" -mtime -7 | wc -l) -gt 0 ]; then
    # Use cached configuration (50 tokens)
    FRAMEWORK=$(jq -r '.framework' "$CACHE_FILE")
    TEST_DIR=$(jq -r '.test_dir' "$CACHE_FILE")
    BASE_URL=$(jq -r '.base_url' "$CACHE_FILE")
    PAGE_PATTERNS=$(jq -r '.page_patterns[]' "$CACHE_FILE")
else
    # Detect framework from scratch (300 tokens)
    # Check package.json for next/react/vue/angular/svelte
    # Cache results for 7 days
    detect_framework
    cache_framework_config
fi

Cache Contents:

• Frontend framework (Next.js, React, Vue, Angular, Svelte)
• Page/route patterns for discovery
• Base URL and dev server configuration
• Test directory structure
• Playwright configuration

Cache Invalidation:

• Time-based: 7 days
• Triggers: package.json changes, playwright.config.ts changes
• Manual: --no-cache flag

3. Template-Based Test Generation (saves 70%)

# Instead of reading existing tests and analyzing patterns,
# use pre-defined templates (200 tokens)

generate_test_from_template() {
    local page_name="$1"
    local page_path="$2"

    # Use inline template - no file reads needed
    cat > "tests/e2e/${page_name}.spec.ts" <<EOF
import { test, expect } from '@playwright/test';

test.describe('${page_name} Page', () => {
  test.beforeEach(async ({ page }) => {
    await page.goto('${page_path}');
  });

  test('should render correctly', async ({ page }) => {
    await page.waitForLoadState('networkidle');
    const heading = page.locator('h1, h2').first();
    await expect(heading).toBeVisible();
  });
});
EOF
}

# vs. Reading 5+ existing test files to infer patterns (1,500+ tokens)

Templates:

• Basic page test
• Form interaction test
• Navigation test
• Responsive test
• Error handling test
• Authentication flow test

4. Grep-Based Route Discovery (saves 80%)

# Instead of reading all page files, use Grep patterns
case $FRAMEWORK in
    nextjs)
        # Fast file discovery with find (100 tokens)
        PAGES=$(find app -name "page.tsx" -o -name "page.jsx" | head -10)
        ;;
    react-spa)
        # Grep for route definitions (150 tokens)
        ROUTES=$(grep -r "path=" src/ --include="*.tsx" --include="*.jsx" | head -10)
        ;;
esac

# vs. Reading and parsing all route files with AST analysis (2,000+ tokens)

Discovery optimization:

• Use find for file-based routing (Next.js, Nuxt)
• Use Grep for code-based routing (React Router, Vue Router)
• Limit results with head -10 (only generate tests for key pages)
• Cache discovered routes for 24 hours

5. Git Diff for Changed Pages (saves 85% during development)

# Only generate tests for changed pages/components
CHANGED_FILES=$(git diff --name-only HEAD)
CHANGED_PAGES=$(echo "$CHANGED_FILES" | grep -E 'pages/|routes/|app/.*page\.')

if [ -n "$CHANGED_PAGES" ]; then
    # Generate tests only for changed pages (200 tokens)
    echo "Generating tests for modified pages:"
    echo "$CHANGED_PAGES"
    for page in $CHANGED_PAGES; do
        generate_test_for_page "$page"
    done
else
    # No page changes, check if this is initial setup
    if [ ! -d "tests/e2e" ]; then
        echo "Initial E2E setup - generating base tests"
    else
        echo "✓ No page changes - E2E tests up to date"
        exit 0  # Early exit, saves ~2,800 tokens
    fi
fi

6. Incremental Test Generation (saves 90% for existing setups)

# Check if E2E infrastructure already exists
if [ -f "playwright.config.ts" ] && [ -d "tests/e2e" ]; then
    # Skip infrastructure setup (saves 1,500 tokens)
    echo "✓ Playwright already configured"
    SKIP_SETUP=true
else
    # Full setup needed
    SKIP_SETUP=false
fi

# Check for existing tests
EXISTING_TESTS=$(find tests/e2e -name "*.spec.ts" -o -name "*.spec.js" 2>/dev/null | wc -l)

if [ "$EXISTING_TESTS" -gt 0 ] && [ -z "$CHANGED_PAGES" ]; then
    echo "✓ E2E tests exist and pages unchanged"
    exit 0  # Early exit, saves ~2,800 tokens
fi

7. Page Object Model Optional Generation (saves 60%)

# Only generate POM if user explicitly requests or project is complex
PAGE_COUNT=$(find app pages src -name "*.tsx" -o -name "*.jsx" 2>/dev/null | wc -l)

if [ "$PAGE_COUNT" -lt 5 ] && [ "$GENERATE_POM" != "true" ]; then
    echo "✓ Skipping Page Object Models (simple app)"
    SKIP_POM=true  # Saves 800 tokens
else
    echo "Generating Page Object Models for maintainability"
    SKIP_POM=false
fi

Optimization Impact by Operation

Realistic Scenarios:

• Initial setup: 1,200-2,000 tokens (full setup with templates)
• Subsequent runs (cache hit): 300-800 tokens (use cached config)
• Single page change: 400-1,000 tokens (generate one test)
• No changes: 50-200 tokens (early exit)

Performance Characteristics

First Run (No Cache):

• Token usage: 1,200-2,000 tokens
• Detects framework and caches configuration
• Discovers all pages/routes
• Generates base test infrastructure
• Creates example tests

Subsequent Runs (Cache Hit):

• Token usage: 300-800 tokens
• Uses cached framework detection
• Only processes changed pages
• 60-75% faster than first run

No Changes (Early Exit):

• Token usage: 50-200 tokens
• Exits if no pages changed
• 95% savings

Single Page Change:

• Token usage: 400-1,000 tokens
• Generates test only for modified page
• Uses templates for fast generation

Cache Structure

.claude/cache/e2e/
├── framework-config.json        # Framework detection (7d TTL)
│   ├── framework                # nextjs, react-spa, vue, etc.
│   ├── test_dir                 # tests/e2e
│   ├── base_url                 # http://localhost:3000
│   ├── page_patterns            # [app/**/page.tsx, pages/*.tsx]
│   ├── dev_command              # npm run dev
│   └── timestamp                # Cache creation time
├── routes.json                  # Discovered routes (1d TTL)
│   ├── pages                    # [{path: "/", file: "app/page.tsx"}]
│   ├── total_pages              # 15
│   └── last_scan                # 2026-01-27T10:00:00Z
├── test-coverage.json           # Generated tests tracking (1d TTL)
│   ├── covered_pages            # ["/", "/about", "/contact"]
│   ├── missing_tests            # ["/admin", "/dashboard"]
│   └── last_update              # 2026-01-27T10:00:00Z
└── playwright-config.json       # Cached playwright setup (7d TTL)
    ├── browsers                 # [chromium, firefox, webkit]
    ├── parallel_workers         # 4
    └── retry_count              # 2

Usage Patterns

Efficient patterns:

# Initial E2E setup
/e2e-generate

# Generate tests for specific page
/e2e-generate --page=dashboard

# Regenerate with fresh framework detection
/e2e-generate --no-cache

# Generate with Page Object Models
/e2e-generate --pom

# Only update changed pages
/e2e-generate --incremental

Flags:

• --no-cache: Bypass framework detection cache
• --page=<name>: Generate test for specific page
• --pom: Force Page Object Model generation
• --incremental: Only generate for changed pages
• --all: Regenerate all tests

Context-Aware Test Generation

Session integration:

# After scaffolding new pages
# Context: /scaffold user-dashboard
# I'll detect: New dashboard routes
# I'll generate: E2E tests for dashboard flows only (saves 80%)

# During feature development
# Context: /session-current shows "user authentication feature"
# I'll prioritize: Auth flow E2E tests
# I'll skip: Unrelated page tests

# After deployment changes
# Context: git diff shows modified routes
# I'll regenerate: Only tests for changed routes (saves 90%)

Integration with other skills:

• After /scaffold → /e2e-generate for new features
• Before /deploy-validate → Ensure E2E tests exist
• With /ci-setup → Add E2E tests to pipeline
• After /test failures → Generate E2E regression tests
• With /playwright-automate → Share cached route discovery

Important optimization notes:

• Never read entire codebase for route discovery
• Use git diff to identify changed pages first
• Cache framework detection for 7 days
• Template-based generation avoids pattern analysis
• Early exit when Playwright not needed
• Incremental generation during development
• Share cache with /playwright-automate and /test skills

Pre-Generation Quality Checks

Optimization for quality checks:

# Only check what's necessary (avoid wasted operations)
if [ -f "playwright.config.ts" ]; then
    echo "✓ Playwright config exists"
    NEEDS_CONFIG=false  # Skip config generation (saves 150 tokens)
else
    NEEDS_CONFIG=true
fi

# Check for test directory
if [ -d "tests/e2e" ] && [ $(ls tests/e2e/*.spec.* 2>/dev/null | wc -l) -gt 0 ]; then
    echo "✓ E2E tests exist"
    HAS_TESTS=true  # Use incremental mode (saves 1,500 tokens)
else
    HAS_TESTS=false
fi

# Cache check results (.claude/cache/e2e/setup-status.json)
# Saves 200 tokens on subsequent runs

Integration with Development Workflow

E2E generation workflow:

# 1. Feature development
/scaffold user-profile           # Create feature
/e2e-generate --page=profile     # Generate E2E tests (400 tokens)

# 2. Test and iterate
/test --e2e                      # Run E2E tests
# [tests fail]
# Fix implementation
/test --e2e                      # Re-run tests

# 3. CI/CD integration
/ci-setup                        # Add E2E tests to pipeline
/deploy-validate                 # Include E2E in pre-deploy checks

# 4. Session tracking
/session-update "Added E2E tests for user profile"
/session-end                     # Include E2E test summary

Shared cache optimization:

• Cache route discovery shared with /playwright-automate
• Framework detection shared with /test and /ci-setup
• Test results shared with /deploy-validate
• Total shared savings: 40-60% across related skills

This optimization approach ensures E2E test generation is fast, cost-effective, and seamlessly integrated into the development workflow while maintaining comprehensive test coverage.