Best Claude Code Skills for Testing

Core software engineering competencies covering planning, reviewing, testing, and debugging across the SDLC

Browser automation and testing using Playwright for web application testing and scraping

Build, navigate, and test iOS apps via simulator automation with XcodeBuild integration

Generate comprehensive test suites with unit, integration, and edge case coverage

End-to-end testing of web applications in a real browser — click, fill, assert, take screenshots, and verify flows before declaring a feature done

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.

/em -stress-test — Business Assumption Stress Testing

Cross-functional what-if modeling for cascading multi-variable scenarios. Unlike single-assumption stress testing, this models compound adversity across all business functions simultaneously. Use when facing complex risk scenarios, strategic decisions with major downside, or whe…

Run tests on BrowserStack. Use when user mentions "browserstack", "cross-browser", "cloud testing", "browser matrix", "test on safari", "test on firefox", or "browser compatibility".

Analyze test coverage gaps. Use when user says "test coverage", "what's not tested", "coverage gaps", "missing tests", "coverage report", or "what needs testing".

Set up Playwright in a project. Use when user says "set up playwright", "add e2e tests", "configure playwright", "testing setup", "init playwright", or "add test infrastructure".

Production-grade Playwright testing toolkit. Use when the user mentions Playwright tests, end-to-end testing, browser automation, fixing flaky tests, test migration, CI/CD testing, or test suites. Generate tests, fix flaky failures, migrate from Cypress/Selenium, sync with TestR…

Use when the user asks to perform security audits, penetration testing, vulnerability scanning, OWASP Top 10 checks, or offensive security assessments. Covers static analysis, dependency scanning, secret detection, API security testing, and pen test report generation.

World-class senior data scientist skill specialising in statistical modeling, experiment design, causal inference, and predictive analytics. Covers A/B testing (sample sizing, two-proportion z-tests, Bonferroni correction), difference-in-differences, feature engineering pipeline…

Generates unit tests, integration tests, and E2E tests for React/Next.js applications. Scans components to create Jest + React Testing Library test stubs, analyzes Istanbul/LCOV coverage reports to surface gaps, scaffolds Playwright test files from Next.js routes, mocks API call…

Security engineering toolkit for threat modeling, vulnerability analysis, secure architecture, and penetration testing. Includes STRIDE analysis, OWASP guidance, cryptography patterns, and security scanning tools. Use when the user asks about security reviews, threat analysis, v…

Test-driven development skill for writing unit tests, generating test fixtures and mocks, analyzing coverage gaps, and guiding red-green-refactor workflows across Jest, Pytest, JUnit, Vitest, and Mocha. Use when the user asks to write tests, improve test coverage, practice TDD, …

Helm chart development agent skill and plugin for Claude Code, Codex, Gemini CLI, Cursor, OpenClaw — chart scaffolding, values design, template patterns, dependency management, security hardening, and chart testing. Use when: user wants to create or improve Helm charts, design v…

Use when the user asks to automate browser tasks, scrape websites, fill forms, capture screenshots, extract structured data from web pages, or build web automation workflows. NOT for testing — use playwright-pro for that.

When the user needs to generate, iterate, or scale ad creative for paid advertising. Use when they say 'write ad copy,' 'generate headlines,' 'create ad variations,' 'bulk creative,' 'iterate on ads,' 'ad copy validation,' 'RSA headlines,' 'Meta ad copy,' 'LinkedIn ad,' or 'crea…

Use when validating product opportunities, mapping assumptions, planning discovery sprints, or testing problem-solution fit before committing delivery resources.

UX research and design toolkit for Senior UX Designer/Researcher including data-driven persona generation, journey mapping, usability testing frameworks, and research synthesis. Use for user research, persona creation, journey mapping, and design validation.

Generate realistic dummy datasets for testing with customizable columns, constraints, and output formats (CSV, JSON, SQL, Python script). Use when creating test data, building mock datasets, or generating sample data for development and demos.

Run a pre-mortem risk analysis on a PRD or launch plan. Categorizes risks as Tigers (real problems), Paper Tigers (overblown concerns), and Elephants (unspoken worries), then classifies as launch-blocking, fast-follow, or track. Use when preparing for launch, stress-testing a pr…

Design experiments to test assumptions for an existing product — prototypes, A/B tests, spikes, and other low-effort validation methods. Use when validating assumptions, testing feature ideas cheaply, or planning product experiments.

Design lean startup experiments (pretotypes) for a new product. Creates XYZ hypotheses and suggests low-effort validation methods like landing pages, explainer videos, and pre-orders. Use when validating a new product idea, creating pretotypes, or testing market demand.

Identify risky assumptions for a feature idea in an existing product across Value, Usability, Viability, and Feasibility. Uses multi-perspective devil's advocate thinking. Use when stress-testing a feature idea, doing risk assessment, or preparing for assumption mapping.

Generate a Lean Canvas with problem, solution, metrics, cost structure, UVP, unfair advantage, channels, segments, and revenue. Use when exploring a lean startup canvas, testing a business hypothesis, or modeling a new venture.

Verifies API contracts between services using consumer-driven contracts, schema validation, and tools like Pact. Use when testing microservices communication, preventing breaking changes, or validating OpenAPI specifications.

HTTP API testing for TypeScript (Supertest) and Python (httpx, pytest). Test REST APIs, GraphQL, request/response validation, authentication, and error handling.

Complete CI/CD guide for Cloudflare Workers using GitHub Actions and GitLab CI. Use for automated testing, deployment pipelines, preview environments, secrets management, or encountering deployment failures, workflow errors, environment configuration issues.

Comprehensive testing guide for Cloudflare Workers using Vitest and @cloudflare/vitest-pool-workers. Use for test setup, binding mocks (D1/KV/R2/DO), integration tests, or encountering test failures, mock errors, coverage issues.

7-phase frontend design review with accessibility (WCAG 2.1 AA), responsive testing, visual polish. Use for PR reviews, UI audits, or encountering contrast issues, broken layouts, accessibility violations, inconsistent spacing, missing focus states.

Mobile app testing with unit tests, UI automation, performance testing. Use for test infrastructure, E2E tests, testing standards, or encountering test framework setup, device farms, flaky tests, platform-specific test errors.

Validate test effectiveness with mutation testing using Stryker (TypeScript/JavaScript with Vitest or bun test via @hughescr/stryker-bun-runner) and mutmut (Python). Find weak tests that pass despite code mutations. Use to improve test quality.

| Nuxt 4 production optimization: hydration, performance, testing with Vitest, deployment to Cloudflare/Vercel/Netlify, and v4 migration. Use when: debugging hydration mismatches, optimizing performance and Core Web Vitals, writing tests with Vitest, deploying to Cloudflare Page…

Pinia v3 Vue state management with defineStore, getters, actions. Use for Vue 3 stores, Nuxt SSR, Vuex migration, or encountering store composition, hydration, testing errors.

Browser automation and E2E testing with Playwright. Auto-detects dev servers, writes clean test scripts. Test pages, fill forms, take screenshots, check responsive design, validate UX, test login flows, check links, automate any browser task. Use for cross-browser testing, visua…

Deploy production recommendation systems with feature stores, caching, A/B testing. Use for personalization APIs, low latency serving, or encountering cache invalidation, experiment tracking, quality monitoring issues.

Creates detailed technical specifications for software projects covering requirements, architecture, APIs, and testing strategies. Use when planning features, documenting system design, or creating architecture decision records.

Modern TypeScript/JavaScript testing with Vitest. Fast unit and integration tests, native ESM support, Vite-powered HMR, and comprehensive mocking. Use for testing TS/JS projects.

Calculate apdex score calculator operations. Auto-activating skill for Performance Testing. Triggers on: apdex score calculator, apdex score calculator Part of the Performance Testing skill category. Use when working with apdex score calculator functionality. Trigger with phrase…

Generate artillery config generator operations. Auto-activating skill for Performance Testing. Triggers on: artillery config generator, artillery config generator Part of the Performance Testing skill category. Use when configuring systems or services. Trigger with phrases like …

Create benchmark suite creator operations. Auto-activating skill for Performance Testing. Triggers on: benchmark suite creator, benchmark suite creator Part of the Performance Testing skill category. Use when working with benchmark suite creator functionality. Trigger with phras…

Execute bottleneck identifier operations. Auto-activating skill for Performance Testing. Triggers on: bottleneck identifier, bottleneck identifier Part of the Performance Testing skill category. Use when working with bottleneck identifier functionality. Trigger with phrases like…

Analyze connection pool analyzer operations. Auto-activating skill for Performance Testing. Triggers on: connection pool analyzer, connection pool analyzer Part of the Performance Testing skill category. Use when analyzing or auditing connection pool analyzer. Trigger with phras…

Configure cpu profiler config operations. Auto-activating skill for Performance Testing. Triggers on: cpu profiler config, cpu profiler config Part of the Performance Testing skill category. Use when configuring systems or services. Trigger with phrases like "cpu profiler config…

Profile database query profiler operations. Auto-activating skill for Performance Testing. Triggers on: database query profiler, database query profiler Part of the Performance Testing skill category. Use when working with database query profiler functionality. Trigger with phra…

Generate flame graph generator operations. Auto-activating skill for Performance Testing. Triggers on: flame graph generator, flame graph generator Part of the Performance Testing skill category. Use when working with flame graph generator functionality. Trigger with phrases lik…

Create gatling scenario creator operations. Auto-activating skill for Performance Testing. Triggers on: gatling scenario creator, gatling scenario creator Part of the Performance Testing skill category. Use when working with gatling scenario creator functionality. Trigger with p…

Analyze gc log analyzer operations. Auto-activating skill for Performance Testing. Triggers on: gc log analyzer, gc log analyzer Part of the Performance Testing skill category. Use when analyzing or auditing gc log analyzer. Trigger with phrases like "gc log analyzer", "gc analy…

Analyze heap dump analyzer operations. Auto-activating skill for Performance Testing. Triggers on: heap dump analyzer, heap dump analyzer Part of the Performance Testing skill category. Use when analyzing or auditing heap dump analyzer. Trigger with phrases like "heap dump analy…

Create jmeter test plan creator operations. Auto-activating skill for Performance Testing. Triggers on: jmeter test plan creator, jmeter test plan creator Part of the Performance Testing skill category. Use when writing or running tests. Trigger with phrases like "jmeter test pl…

Generate k6 script generator operations. Auto-activating skill for Performance Testing. Triggers on: k6 script generator, k6 script generator Part of the Performance Testing skill category. Use when working with k6 script generator functionality. Trigger with phrases like "k6 sc…

Plan load test scenario planner operations. Auto-activating skill for Performance Testing. Triggers on: load test scenario planner, load test scenario planner Part of the Performance Testing skill category. Use when writing or running tests. Trigger with phrases like "load test …

Create locust test creator operations. Auto-activating skill for Performance Testing. Triggers on: locust test creator, locust test creator Part of the Performance Testing skill category. Use when writing or running tests. Trigger with phrases like "locust test creator", "locust…

Configure memory profiler setup operations. Auto-activating skill for Performance Testing. Triggers on: memory profiler setup, memory profiler setup Part of the Performance Testing skill category. Use when working with memory profiler setup functionality. Trigger with phrases li…

Test network latency tester operations. Auto-activating skill for Performance Testing. Triggers on: network latency tester, network latency tester Part of the Performance Testing skill category. Use when writing or running tests. Trigger with phrases like "network latency tester…

Analyze percentile analyzer operations. Auto-activating skill for Performance Testing. Triggers on: percentile analyzer, percentile analyzer Part of the Performance Testing skill category. Use when analyzing or auditing percentile analyzer. Trigger with phrases like "percentile …

Create performance baseline creator operations. Auto-activating skill for Performance Testing. Triggers on: performance baseline creator, performance baseline creator Part of the Performance Testing skill category. Use when working with performance baseline creator functionality…

Analyze response time analyzer operations. Auto-activating skill for Performance Testing. Triggers on: response time analyzer, response time analyzer Part of the Performance Testing skill category. Use when analyzing or auditing response time analyzer. Trigger with phrases like …

Plan soak test planner operations. Auto-activating skill for Performance Testing. Triggers on: soak test planner, soak test planner Part of the Performance Testing skill category. Use when writing or running tests. Trigger with phrases like "soak test planner", "soak planner", "…

Configure spike test setup operations. Auto-activating skill for Performance Testing. Triggers on: spike test setup, spike test setup Part of the Performance Testing skill category. Use when writing or running tests. Trigger with phrases like "spike test setup", "spike setup", "…

Configure stress test config operations. Auto-activating skill for Performance Testing. Triggers on: stress test config, stress test config Part of the Performance Testing skill category. Use when writing or running tests. Trigger with phrases like "stress test config", "stress …

Analyze thread dump analyzer operations. Auto-activating skill for Performance Testing. Triggers on: thread dump analyzer, thread dump analyzer Part of the Performance Testing skill category. Use when analyzing or auditing thread dump analyzer. Trigger with phrases like "thread …

Calculate throughput calculator operations. Auto-activating skill for Performance Testing. Triggers on: throughput calculator, throughput calculator Part of the Performance Testing skill category. Use when working with throughput calculator functionality. Trigger with phrases li…

Assist with api testing helper operations. Auto-activating skill for API Development. Triggers on: api testing helper, api testing helper Part of the API Development skill category. Use when working with APIs or building integrations. Trigger with phrases like "api testing helpe…

Automated penetration testing — web, API, browser, GitHub, and local code. Zero false positives. Use when user wants to hack-test their app, find vulnerabilities, or run security pentesting.

Visual Regression Testing — screenshot comparison before and after changes. Use when user wants to check for visual regressions, compare UI changes, or verify CSS/layout changes didn't break anything.