Use when writing or changing tests, adding mocks, or tempted to add test-only methods to production code - prevents testing mock behavior, production pollution with test-only methods, and mocking without understanding dependencies
Use when tests have race conditions, timing dependencies, or inconsistent pass/fail behavior - replaces arbitrary timeouts with condition polling to wait for actual state changes, eliminating flaky tests from timing guesses
Complete browser automation with Playwright. Auto-detects dev servers, writes clean test scripts to /tmp. Test pages, fill forms, take screenshots, check responsive design, validate UX, test login flows, check links, automate any browser task. Use when user wants to test websites, automate browser interactions, validate web functionality, or perform any browser-based testing.
Run the project's formatter, linters, and mypy checks in the required order, fixing issues and managing any needed stub dependencies via uv.
Write focused pytest tests as standalone functions (one test per function), avoiding test classes.
Use this when writing or reviewing code - provides project-specific coding standards
Reproduce, isolate, and fix a bug (or failing build/test), then summarize root cause, fix, and verification steps. Use when the user reports a bug, regression, or failing build/test and wants a fix.
Unit and E2E testing strategies with Docker.
Security practices for React (XSS, Auth, Dependencies).
Modern TypeScript standards for type safety, performance, and maintainability.
Environment variables validation and ConfigModule setup.
Authentication, RBAC, and Hardening standards.
Fetch API, Caching, and Revalidation strategies.
HTTP networking standards using Dio and Retrofit with Auth interceptors.
Secure token storage (HttpOnly Cookies) and Middleware patterns.
Unit, widget, and integration testing using mocktail and bloc_test.
Testing strategies with RTL and Jest/Vitest.
Standards for automated service locator setup using injectable and get_it.
Test changes in a dedicated Emacs session. Good for validating behavior and UI results.
Handle code review feedback with technical rigor. Don't blindly agree - verify before implementing.
Review code for best practices, potential bugs, security vulnerabilities, and performance issues
Review code for best practices and potential issues
Use when writing or changing tests, adding mocks, or tempted to add test-only methods to production code - prevents testing mock behavior, production pollution with test-only methods, and mocking without understanding dependencies
