Fix async/await bugs, closure issues, memory leaks, event loop problems, ES6+ syntax, and production JavaScript issues
Event listeners attached to DOM elements are never removed, causing memory leaks when elements are destroyed.
All callbacks reference the same loop variable, causing all to use the final value.
Async function returns before promise resolves, causing undefined behavior.
this context is lost when method is passed as callback, causing undefined errors.
Promise rejections are not caught, causing unhandled rejection errors.
setInterval timers continue running after component cleanup, causing memory leaks.
Directly mutating nested objects causes unexpected behavior in state management.
User input is merged into objects without validation, allowing prototype pollution attacks.
Variable is used before declaration, causing unexpected undefined values.
Invalid JSON strings cause unhandled exceptions, crashing the application.
Multiple API calls are made in parallel but results are processed in wrong order, causing data corruption.
Recursive function lacks base case, causing stack overflow and infinite recursion.
Object used as WeakMap key is garbage collected before expected, causing data loss.
Synchronous CPU-intensive operation blocks event loop, freezing entire application.
Fetch request fails due to CORS policy blocking cross-origin requests.
Objects reference each other in circular pattern, preventing garbage collection.
User input is directly inserted into DOM without sanitization, allowing XSS attacks.
Debounce implementation doesn't properly cancel previous timeouts, causing multiple executions.
Generator throws error but caller doesn't handle it, causing unhandled exception.
Proxy handler intercepts operations but doesn't forward to target, breaking functionality.
Service worker caches old version of assets, preventing updates from being served.
WebSocket connection fails but doesn't attempt reconnection, leaving app disconnected.
Intersection Observer continues observing after component unmounts, causing memory leaks.
Multiple web workers access SharedArrayBuffer simultaneously without synchronization, causing data corruption.
New function is created on every render, causing unnecessary re-renders of child components.