vite

Assists with unit and integration testing using Vitest, a Vite-native test runner. Use when writing tests, configuring mocks, setting up coverage, or migrating from Jest. Trigger words: vitest, unit testing, test runner, vi.fn, vi.mock, test coverage, jest replacement.

Build cross-browser extensions with WXT — the modern framework for Chrome, Firefox, Safari, and Edge extensions. Use when someone asks to "build a browser extension", "Chrome extension with React", "WXT framework", "cross- browser extension", "manifest v3 extension", "build Firefox extension", or "browser extension with TypeScript". Covers content scripts, background workers, popup/options pages, storage, messaging, and publishing.

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.

Review UI code for Web Interface Guidelines compliance. Use when asked to "review my UI", "check accessibility", "audit design", "review UX", or "check my site against best practices".

React and Next.js performance optimization guidelines from Vercel Engineering. This skill should be used when writing, reviewing, or refactoring React/Next.js code to ensure optimal performance patterns. Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance improvements.

React composition patterns that scale. Use when refactoring components with boolean prop proliferation, building flexible component libraries, or designing reusable APIs. Triggers on tasks involving compound components, render props, context providers, or component architecture. Includes React 19 API changes.

Test UI components the way users interact with them using Testing Library — query by role, text, and label instead of implementation details. Use when someone asks to "test React components", "Testing Library", "user-centric testing", "test accessibility", "test without implementation details", or "render and query components in tests". Covers React Testing Library, queries, user events, async testing, and accessibility assertions.

Build UIs with Tailwind CSS — utility classes, responsive design, dark mode, custom configuration, component patterns, animations, plugins, and design system setup. Use when tasks involve styling web applications, configuring design tokens, building responsive layouts, or migrating from other CSS approaches.

Create new skills, modify and improve existing skills, and measure skill performance. Use when users want to create a skill from scratch, edit, or optimize an existing skill, run evals to test a skill, benchmark skill performance with variance analysis, or optimize a skill's description for better triggering accuracy.

Expert guidance for integrating and building applications with shadcn/ui components, including component discovery, installation, customization, and best practices.

Scan code for security vulnerabilities, misconfigurations, and exposed secrets. Use when a user asks to audit security, find vulnerabilities, check for OWASP issues, scan for secrets, review dependencies for CVEs, detect SQL injection, find XSS vulnerabilities, or harden an application. Covers OWASP Top 10, dependency auditing, secrets detection, and generates fix recommendations with severity ratings.

Write and maintain end-to-end tests with Playwright. Use when someone asks to "add e2e tests", "test my web app", "set up Playwright", "write browser tests", "test login flow", "visual regression testing", "test across browsers", or "automate UI testing". Covers test setup, page objects, authentication, API mocking, visual comparisons, and CI integration.