How are the test results reported?

The skill captures screenshots for every failure state, logs console errors, and provides a structured summary comparing expected vs. actual application behavior.

Does it automatically fix the errors it finds?

It is a diagnostic tool that identifies how your app fails. Once failures are identified, you can use Claude's coding capabilities to implement the necessary fixes.

Can I test specific API endpoints for failures?

Yes, the skill uses Playwright routing to intercept and mock responses for specific URL patterns, allowing you to target specific backend services.

Does this skill require a specific browser?

Yes, it requires a Chromium-based browser because it utilizes Chrome DevTools Protocol (CDP) for advanced network emulation and resource blocking.

Can I simulate storage full errors?

Yes, it includes a dedicated step to fill localStorage or override setItem to trigger QuotaExceededError exceptions systematically.

Error Injection Tester

Name: Error Injection Tester
Author: anouar1991

byanouar1991

•

Security & Testing

Systematically injects network, API, and JavaScript failures into web applications to evaluate resilience and graceful degradation.

The Error Injection Tester is a specialized Playwright-based skill designed to stress-test web applications by simulating real-world failure scenarios. It allows developers and QA engineers to verify how their UI handles offline states, 500/403 API errors, blocked assets, JavaScript exceptions, and storage quota limits. By providing isolated injection steps and automated screenshot capture, it helps identify brittle error boundaries and ensures that fallback UIs provide a user-friendly experience even under adverse conditions like slow 3G networks or server timeouts.

Key Features

01Intercepts API calls to mock 500 Internal Server Errors, 403 Forbidden, and timeouts.

021 GitHub stars

03Simulates localStorage QuotaExceededErrors to test storage reliability and data persistence.

04Blocks specific resource types like CSS, JS, or images to test visual fallbacks.

05Injects unhandled JavaScript exceptions and promise rejections to verify error boundaries.

06Simulates offline mode and variable network speeds (3G) using CDP.

Use Cases

01Verifying PWA offline behavior and service worker reliability before deployment.

02Testing front-end error boundaries and user-facing error messages for API failures.

03Validating application loading states and visual stability on high-latency mobile networks.

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add anouar1991/binarypetsclaude error-injection-tester

For use in Claude.ai and ChatGPT

Download Skill