JavaScript Best Practices Performance optimization and code style patterns for JavaScript and TypeScript code. Contains 17 rules focused on reducing unnecessary computation, optimizing data structures, and maintaining consistent conventions. When to Apply Reference these guidelines when: - Writing loops or array operations - Working with data structures (Map, Set, arrays) - Manipulating the DOM directly - Caching values or function results - Optimizing hot code paths - Declaring variables or functions Rules Summary const-let-usage (MEDIUM) — @rules/const-let-usage.md Use at module level, insi…