Testing

Browser-use automates browser interactions for web testing, form filling, screenshots, and data extraction. It provides a persistent browser session CLI that supports headless Chromium, real Chrome with login sessions, and cloud-hosted browsers for complex multi-step web automation workflows.

This skill provides a complete toolkit for testing local web applications using Playwright. It includes helper scripts for managing server lifecycles, capturing browser console logs, discovering page elements, and automating interactions with both dynamic web apps and static HTML files.

A comprehensive guide to Test-Driven Development (TDD) that enforces the red-green-refactor cycle. Provides strict workflows for writing tests before implementation, common rationalizations to avoid, and testing anti-patterns to watch for when creating mocks or test utilities.

This skill teaches a rigorous 4-phase debugging methodology: Investigation, Pattern Analysis, Hypothesis Testing, and Implementation. It includes practical utilities for condition-based test waiting and test pollution detection, along with documentation on root cause tracing and defense-in-depth validation strategies.

Guides the creation of well-structured Claude Code skills by applying Test-Driven Development principles to documentation. Includes templates for SKILL.md structure, testing methodologies using subagents with pressure scenarios, and optimization techniques for skill discovery (Claude Search Optimization).

This skill provides a comprehensive verification workflow for Claude Code sessions. It runs build verification, type checking, linting, test suites with coverage, basic security scans for leaked secrets, and diff reviews to ensure code quality before creating pull requests.

This skill enforces test-driven development principles by guiding developers through TDD workflows. It provides comprehensive patterns for unit tests, integration tests, and E2E tests with examples using Jest, Vitest, and Playwright, along with mocking strategies and coverage requirements.

A comprehensive guide for Go testing that covers table-driven tests, subtests, benchmarks, fuzzing, and test coverage. Follows TDD (Test-Driven Development) methodology with idiomatic Go practices and includes examples for mocking, HTTP handler testing, and CI/CD integration.

Eval Harness provides a formal evaluation framework for Claude Code sessions, implementing eval-driven development (EDD) principles. It helps define expected behaviors before implementation, run evals continuously during development, and track pass/fail metrics for both capability and regression tests.

A comprehensive testing guide for Temporal Python workflows. Covers unit testing with time-skipping, integration testing with mocked activities, replay testing for determinism validation, and local development setup with Docker Compose and pytest configuration.

A comprehensive guide for implementing JavaScript and TypeScript testing strategies. Covers unit testing, integration testing, mocking patterns, React component testing with Testing Library, test fixtures, and best practices for test-driven development using Jest and Vitest.

A comprehensive guide for writing unit tests for shell scripts using Bats (Bash Automated Testing System). Covers test structure, assertions, mocking, fixtures, CI/CD integration, and best practices for production-grade shell testing.

This skill provides comprehensive Python testing patterns using pytest. It covers unit testing, fixtures for setup/teardown, mocking external dependencies, parameterized tests, async testing, property-based testing with Hypothesis, database testing, and CI/CD integration. The guide includes best practices for test organization, naming, and coverage reporting.

This skill helps manage major dependency version upgrades in JavaScript/TypeScript projects. It provides strategies for compatibility analysis, staged upgrade workflows, codemod automation, and comprehensive testing approaches including rollback plans and automated update configuration with Renovate or Dependabot.

This skill provides extensive patterns and best practices for authentication implementation (JWT, OAuth2, sessions), monorepo management (Turborepo, Nx, Bazel), debugging strategies, E2E testing with Playwright/Cypress, error handling, Git workflows, and code review excellence. It serves as a reference guide for building secure, scalable applications.

A comprehensive documentation resource for writing production-grade Bash scripts. It covers defensive programming techniques, POSIX compliance, Bats testing patterns, and ShellCheck configuration for static analysis and code quality.

This skill provides comprehensive guidance for JavaScript and TypeScript development, covering testing frameworks (Jest, Vitest, Testing Library), modern ES6+ patterns including async/await and functional programming, Node.js backend architecture with Express/Fastify, and advanced TypeScript type system features like generics and conditional types.

This skill collection provides expert assistance for modern Python development. It includes specialized agents for Django, FastAPI, and general Python development, along with comprehensive documentation for async programming patterns, Python packaging with pyproject.toml, performance profiling and optimization, pytest testing strategies, and the fast uv package manager.

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.

Use when about to claim work is complete, fixed, or passing, before committing or creating PRs - requires running verification commands and confirming output before making any success claims; evidence before assertions always

Agent Browser provides instructions for using Vercel's agent-browser CLI tool for headless browser automation. It enables web page interaction including navigation, form filling, clicking elements, taking screenshots, and scraping data using ref-based element selection from accessibility snapshots.

Comprehensive PR review toolkit with 6 specialized agents for analyzing code comments, test coverage, error handling, type design, code quality, and simplification. Each agent focuses on a specific aspect of code quality and provides actionable feedback.

Wycheproof is a documentation skill that teaches developers how to validate cryptographic implementations using test vectors. It covers testing workflows for AES-GCM, ECDSA, ECDH, RSA, and other algorithms, with examples in Python and JavaScript.

A comprehensive property-based testing (PBT) guide that helps Claude detect PBT opportunities, generate tests, review existing tests, and apply Property-Driven Development across Python, JavaScript, Rust, Go, Java, and 10+ other languages including Solidity smart contracts.

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.

A comprehensive Terraform and OpenTofu skill that provides best practices for module development, testing strategies (native tests and Terratest), CI/CD workflows, security compliance, and code patterns. It includes decision matrices for choosing testing frameworks, naming conventions, and detailed reference guides for production-grade infrastructure-as-code.

This skill helps teams document and test user journeys through their applications. It provides templates for mapping critical user flows (signup, checkout, etc.), Playwright test patterns for E2E journey validation, and UX checklists to ensure experiences are clear, fast, and forgiving. The skill focuses on testing real user experiences rather than just feature specifications.

This skill provides comprehensive TypeScript development guidelines including strict compiler configuration, ESLint setup with type checking, Jest testing patterns, GitHub Actions CI/CD workflows, and pre-commit hooks. It documents best practices and anti-patterns to help maintain high code quality in TypeScript projects.

A comprehensive React web development skill that enforces test-first development (TDD) methodology. It provides patterns for functional components, custom hooks, state management with Zustand and React Query, routing with React Router, form handling with React Hook Form and Zod, and testing with React Testing Library and Playwright.

A comprehensive React Native development guide covering project structure, component patterns, state management with Zustand and React Query, testing with React Native Testing Library, and platform-specific code handling. This is a pure documentation skill with no executable scripts.