spuneiartur/webapp-testing

Web Application Testing

To test local web applications, write native Python Playwright scripts.

Helper Scripts Available:

• scripts/with_server.py - Manages server lifecycle (supports multiple servers)

Always run scripts with --help first to see usage. DO NOT read the source until you try running the script first and find that a customized solution is abslutely necessary. These scripts can be very large and thus pollute your context window. They exist to be called directly as black-box scripts rather than ingested into your context window.

Decision Tree: Choosing Your Approach

User task → Is it static HTML?
    ├─ Yes → Read HTML file directly to identify selectors
    │         ├─ Success → Write Playwright script using selectors
    │         └─ Fails/Incomplete → Treat as dynamic (below)
    │
    └─ No (dynamic webapp) → Is the server already running?
        ├─ No → Run: python scripts/with_server.py --help
        │        Then use the helper + write simplified Playwright script
        │
        └─ Yes → Reconnaissance-then-action:
            1. Navigate and wait for networkidle
            2. Take screenshot or inspect DOM
            3. Identify selectors from rendered state
            4. Execute actions with discovered selectors

Example: Using with_server.py

To start a server, run --help first, then use the helper:

Single server:

python scripts/with_server.py --server "npm run dev" --port 5173 -- python your_automation.py

Multiple servers (e.g., backend + frontend):

python scripts/with_server.py \
  --server "cd backend && python server.py" --port 3000 \
  --server "cd frontend && npm run dev" --port 5173 \
  -- python your_automation.py

To create an automation script, include only Playwright logic (servers are managed automatically):

from playwright.sync_api import sync_playwright

with sync_playwright() as p:
    browser = p.chromium.launch(headless=True) # Always launch chromium in headless mode
    page = browser.new_page()
    page.goto('http://localhost:5173') # Server already running and ready
    page.wait_for_load_state('networkidle') # CRITICAL: Wait for JS to execute
    # ... your automation logic
    browser.close()

Reconnaissance-Then-Action Pattern

1. Inspect rendered DOM:

   page.screenshot(path='/tmp/inspect.png', full_page=True)
   content = page.content()
   page.locator('button').all()
   

2. Identify selectors from inspection results

3. Execute actions using discovered selectors

Common Pitfall

❌ Don't inspect the DOM before waiting for networkidle on dynamic apps ✅ Do wait for page.wait_for_load_state('networkidle') before inspection

Best Practices

• Use bundled scripts as black boxes - To accomplish a task, consider whether one of the scripts available in scripts/ can help. These scripts handle common, complex workflows reliably without cluttering the context window. Use --help to see usage, then invoke directly.
• Use sync_playwright() for synchronous scripts
• Always close the browser when done
• Use descriptive selectors: text=, role=, CSS selectors, or IDs
• Add appropriate waits: page.wait_for_selector() or page.wait_for_timeout()

Reference Files

• examples/ - Examples showing common patterns:
  • element_discovery.py - Discovering buttons, links, and inputs on a page
  • static_html_automation.py - Using file:// URLs for local HTML
  • console_logging.py - Capturing console logs during automation

Next.js-Specific Testing Patterns

When testing a Next.js Pages Router application, use these additional patterns.

Starting the Dev Server

python scripts/with_server.py --server "npm run dev" --port 3000 -- python your_test.py

Testing Auth-Protected Pages

Admin pages use getServerSideProps with checkAuth — they redirect to /login without valid auth:

# Test that admin pages redirect to login when unauthenticated
page.goto('http://localhost:3000/admin/articles')
page.wait_for_load_state('networkidle')
assert '/login' in page.url, f"Expected redirect to /login, got {page.url}"

Testing Dynamic Routes

Pages like /produse/[slug] and /admin/articles/edit/[id]:

# Test a dynamic product page
page.goto('http://localhost:3000/produse/some-product-slug')
page.wait_for_load_state('networkidle')
# Verify product content loaded
assert page.locator('h1').count() > 0

# Test 404 for non-existent slug
response = page.goto('http://localhost:3000/produse/nonexistent-slug-xyz')
assert response.status == 404

Testing Middleware Behavior

The project uses middleware for www→non-www redirects and maintenance mode:

# Test www redirect (if applicable)
# Test that maintenance mode works when MAINTENANCE=true

# Test that static files bypass middleware
page.goto('http://localhost:3000/images/logo.png')
assert page.locator('img').count() > 0 or response.status == 200

Checking SEO Meta Tags

Verify NextSeo renders correct meta tags:

page.goto('http://localhost:3000/about')
page.wait_for_load_state('networkidle')

# Check title
title = page.title()
assert 'About' in title

# Check meta description
meta_desc = page.locator('meta[name="description"]').get_attribute('content')
assert meta_desc and len(meta_desc) > 0

# Check OpenGraph
og_title = page.locator('meta[property="og:title"]').get_attribute('content')
assert og_title and len(og_title) > 0

Testing Form Submissions

For React Hook Form-based forms:

# Fill and submit a form
page.goto('http://localhost:3000/contact')
page.wait_for_load_state('networkidle')

page.fill('input[name="name"]', 'Test User')
page.fill('input[name="email"]', '[email protected]')
page.fill('textarea[name="message"]', 'Test message content')
page.click('button[type="submit"]')

# Wait for success state
page.wait_for_selector('.toast-success', timeout=5000)