javascript-pro

Load detailed guidance based on context: When implementing JavaScript features, provide: - Building vanilla JavaScript applications - Implementing async/await patterns and Promise handling - Working with modern module systems (ESM/CJS) - Optimizing browser performance and memory usage - Developing Node.js backend services - Implementing Web Workers, Service Workers, or browser APIs - Analyze requirements — Review package.json , module system, Node version, browser targets; confirm .js / .mjs / .cjs conventions - Design architecture — Plan modules, async flows, and error handling strategies - Implement — Write ES2023+ code with proper patterns and optimisations - Validate — Run linter ( eslint --fix ); if linter fails, fix all reported issues and re-run before proceeding. Check for memory leaks with DevTools or --inspect , verify bundle size; if leaks are found, resolve them before continuing - Test — Write comprehensive tests with Jest achieving 85%+ coverage; if coverage falls short, add missing cases and re-run. Confirm no unhandled Promise rejections - Use ES2023+ features exclusively - Use X | null or X | undefined patterns - Use optional chaining ( ?. ) and nullish coalescing ( ?? ) - Use async/await for all asynchronous operations - Use ESM ( import / export ) for new projects - Implement proper error handling with try/catch - Add JSDoc comments for complex functions -...