javascript-pro

Modern ES2023+ JavaScript implementation with async/await, ESM modules, and Node.js best practices. Load detailed guidance based on context: When implementing JavaScript features, provide: Documentation - Covers vanilla JavaScript, Promise-based async flows, Web Workers, Fetch API, and browser performance optimization - Enforces ES2023+ syntax, optional chaining, nullish coalescing, and functional programming patterns - Includes comprehensive error handling, memory leak detection, and Jest test coverage validation (85%+ target) - Provides reference guides for async patterns, module systems (ESM/CJS), browser APIs, and Node.js essentials - 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...