webapp-testing

Web Application Testing

Write native Python Playwright scripts to test local web applications.

When to Use

✅ Use for:

• E2E testing of web applications
• UI automation and interaction testing
• Visual regression testing
• Browser log capture and debugging
• Screenshot capture for verification
• Form submission and validation testing

❌ NOT for:

• API-only testing without a browser (use requests/httpx)
• Unit testing of individual functions
• Mobile app testing (use Appium)
• Load/performance testing (use k6/Locust)

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 → Start server first, then run Playwright
        │
        └─ 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

Core Playwright Patterns

Basic Test Structure

from playwright.sync_api import sync_playwright

with sync_playwright() as p:
    browser = p.chromium.launch(headless=True)  # Always headless
    page = browser.new_page()
    page.goto('http://localhost:5173')
    page.wait_for_load_state('networkidle')  # CRITICAL for SPAs

    # ... your test logic

    browser.close()

Reconnaissance-Then-Action Pattern

Step 1: Inspect rendered DOM

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

Step 2: Identify selectors from inspection results

Step 3: Execute actions using discovered selectors

Selector Strategy (Priority Order)

1. Role-based (best for accessibility):

   page.get_by_role("button", name="Submit")
   page.get_by_role("textbox", name="Email")