---
name: webapp-testing
effort: medium
description: Toolkit for interacting with and testing local web applications using Playwright. Supports verifying frontend functionality, debugging UI behavior, capturing browser screenshots, and viewing browser logs.
license: Complete terms in LICENSE.txt
---

# Web Application Testing

## Project Context

**Reads from `baldart.config.yml`:** `paths.design_system`.
**Gated by features:** `features.has_design_system` (Design System Validation section is BLOCKING when `true`), `features.multi_tenant_theming` (theming token-pair assertion activates when `true`).
**Overlay:** loads `.baldart/overlays/webapp-testing.md` if present — project-specific test URLs, auth helpers.
**On missing/empty keys:** ask the user; do not assume defaults. See `framework/agents/project-context.md` § 3.

## Effort

**Baseline:** `effort: medium` (frontmatter). **Inline override:** pass
`effort=<low|medium|high|xhigh|max>` anywhere in the invocation to scale
reasoning depth for this run — detect it once at kickoff and strip the token
before consuming user input. Level→behavior mapping, parsing contract, and
precedence caveats: `framework/agents/effort-protocol.md`.


---

## E2E Review Integration (since v3.18.0)

This skill is the tooling layer consumed by `/e2e-review` in **compliance-only
mode** (Phase 2 cascade level c) and as a fallback for runtime inspection.
When invoked from the orchestrator:

- Use the Python Playwright helpers to fetch the rendered DOM's computed
  styles (CSS color / spacing / radius / shadow values) for the routes in
  scope when no mockup image is available.
- The compliance check reads `${paths.design_system}/tokens-reference.md` and
  flags any computed value that does not match a token (the
  `visual-fidelity-verifier` agent owns the actual cross-reference; this
  skill only surfaces the runtime values).
- The server lifecycle helper (`scripts/with_server.py`) MAY be used to start
  / stop the dev server when the orchestrator runs outside a worktree that
  already has one running.

No logic of this skill changes for E2E-review consumption — see
[`framework/.claude/skills/e2e-review/SKILL.md`](../e2e-review/SKILL.md)
Phase 2 (compliance-only branch) for the full contract.

---

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:**
```bash
python scripts/with_server.py --server "npm run dev" --port 5173 -- python your_automation.py
```

**Multiple servers (e.g., backend + frontend):**
```bash
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):
```python
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**:
   ```python
   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

## Design System Compliance (Visual Regression Dimension)

When tests validate UI components (not just functional behavior), conformity to the Design
System SSOT is a first-class test dimension:

1. Before writing a visual test, read `${paths.design_system}/INDEX.md` and the relevant
   `${paths.design_system}/components/<Name>.md` to understand the expected variants, states,
   and required visual contract.
2. Write assertions that reflect component doc expectations — variant-specific classes,
   required props, accessibility attributes. Example: a "primary" button test should assert
   the tokens / classes the component doc defines for that variant.
3. For themed surfaces (when `features.multi_tenant_theming: true`), validate token pairs from the
   project's theming pattern doc — `${paths.design_system}/patterns/<theme>.md` (the exact filename is
   declared in `.baldart/overlays/ui-design.md`) — asserting bg + matching text token rather than
   specific hex.
4. Motion-sensitive screens MUST include a reduced-motion pass (emulate via
   `page.emulate_media(reduced_motion='reduce')`) per the project's motion pattern doc —
   `${paths.design_system}/patterns/animations.md` (or the motion doc declared in
   `.baldart/overlays/ui-design.md`).

## 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
