Web App Testing

What it does

Web App Testing gives an agent a practical method for observing a local web app through Python Playwright. It distinguishes inspecting static HTML from testing a JavaScript-rendered app, then bases interactions on elements found in the rendered page. Its bundled server helper can manage one or several development processes so test logic can concentrate on browser behavior.

When to use it

• A product filter changes its label but may leave the result list unchanged. Verify the visible result state after interacting.
• A frontend requires both an API server and a development server. Use the server lifecycle helper after reviewing its scope.
• A regression appears only after opening a modal or navigating between screens. Capture screenshots and browser logs around that sequence.

Step-by-step workflow

1. Record the exact route, starting data, action and expected visible outcome. A test needs an observable result, not just a click that returns successfully.
2. For static pages, inspect HTML for selectors. For dynamic pages, start the app if necessary and inspect the page after JavaScript has rendered. The source uses network-idle waiting; persistent connections may require a more specific readiness condition.
3. Discover controls from the rendered DOM. Prefer roles, accessible names and stable identifiers instead of inventing selectors from assumptions.
4. Write a focused Python Playwright script. Exercise the control, assert the changed state and capture screenshots or console output when useful.
5. Close the browser and stop helper-managed processes. Repeat the failing scenario after a fix with the same input and expected result.

Example request

Use webapp-testing on our local catalogue at http://localhost:5173. Inspect the rendered filter controls. Select the Testing category and assert that matching cards remain while unrelated cards disappear. Then search for a term with no matches and verify an informative empty state. Capture a screenshot of each result and report relevant console errors. Use existing project dependencies; identify missing prerequisites before changing them.

Worked example

A meaningful filter test checks the initial count, changes the category, then checks card titles or category labels in the resulting list. A click-only script could pass even when the filter is disconnected. Add the no-results case because it exercises a different UI branch. If the page uses long-lived connections, wait for the result region to settle rather than waiting indefinitely for all network traffic to stop.

What you get

A focused browser test plus observable results such as screenshots or console findings.

How to evaluate the result

• Expect a reproducible test command, the browser script and a clear pass/fail result for each scenario. Screenshots supplement assertions; they do not replace them.
• Check that a deliberately wrong expected result makes the test fail. This catches tests that perform actions without validating outcomes.
• Document the tested route and data state. A passing local test does not prove production authentication, every browser or every screen size works.

What you need

Python, Playwright and its browser runtime; access to a local application.

Setup and activation

The publisher README documents Claude Code’s anthropic-agent-skills marketplace and its example-skills plugin. After reviewing the selected source and bundled files, enable the appropriate plugin in your client and mention the skill by name. Keep the complete skill folder so relative references still resolve. Plugin availability and commands depend on the client version; the publisher README is linked below. This page installs nothing. Before local installation, review and security-scan the exact source/version; catalogue inclusion is not security approval.

Limits and considerations

This is not a substitute for backend authorization tests, load testing or a full accessibility audit. It needs a reachable application and Python Playwright with browser binaries. Review helper scripts before allowing them to start processes in your environment.

Related workflows

• Use after Frontend Design to verify implemented interactions.
• Use existing repository end-to-end tests when they already cover the flow.

License and reuse

Apache License 2.0, confirmed in this skill’s LICENSE.txt. Reuse remains subject to the license’s notice and other requirements; inspect the exact version and any separately licensed assets.

Further reading

• Publisher setup and repository README
• Skill-specific license