Debugging Articles

State mutation errors plague 70% of Redux applications despite modern tooling, while Redux Toolkit 2.0 breaking changes force widespread migration. RTK Query cache invalidation timing issues, TypeScript strict mode conflicts, React 18/19 compatibility demands, and performance bottlenecks with lar...

Next.js caching is complex and more than a bit magical. This complexity is a source silent errors in the form of stale and incorrect data.

Error handling in NextJS doesn't have to be complex. TrackJS handles all the places where NextJS can fail

Did JavaScript break my store? Monitor errors in your Shopify store with TrackJS make sure your store keeps running great.

15 hard-won lessons from 15 years building web apps: write as little JavaScript as possible, use progressive enhancement, monitor everything, and keep it simple. Most valuable apps are under 10,000 lines of code - complexity kills maintainability.

Microsoft made query string parsing worse in .NET Core. The old HttpUtility.ParseQueryString() returns a secret HttpValueCollection that handles multiple values and URL encoding elegantly. The new approach splits functionality across three classes - QueryHelpers, QueryString, and StringValues - m...

TrackJS launches automated Global Error Statistics, providing weekly public data on client-side JavaScript quality across the web. The report tracks common errors, browsers, and operating systems with automatic calculations replacing the manual 2015 State of JavaScript Errors report - Script Erro...

Microsoft Edge threw errors when Facebook's SDK used the unsupported referrerPolicy option in fetch requests. The workaround is avoiding Request objects or explicitly setting referrer values instead.

Three essential tips to prevent ad blocker breakage: Always safety-check external analytics functions with window.ga && ga() syntax, avoid advertising keywords in URLs/classnames/filenames (like "track", "sponsor", ad dimensions), and test locally with uBlock Origin to catch issues before users do.

RemoteJS solves the nightmare of debugging remote device bugs through real-time JavaScript debugging via WebSocket connections. Born from TrackJS users hacking together monitoring for remote debugging, it lets you execute commands, inspect state, and view screens on devices you can't physically a...

TrackJS debugs their own "Cannot read property 'id' of undefined" error affecting 6 users on critical /account pages. The culprit: PJAX navigation causing lazy-loaded Stripe JavaScript to execute on wrong pages when users navigate quickly on slow networks, creating unexpected execution context.

Cut through web "background radiation" with strategic JavaScript error monitoring: ignore known noisy errors, set up targeted alerts (new/trending/rate/daily), focus on user impact and critical pages, track versions for releases, and use status filtering to manage bug workflows effectively.

JavaScript apps inevitably break in production - learn how to capture errors with global handlers, understand error context through telemetry, and systematically debug the five most common categories of web application failures to build resilient applications.

Unhandled promise rejections silently break applications without triggering traditional error handlers. Learn how modern browsers now provide standardized events to catch these elusive errors and why proper promise error handling is crucial for robust applications.

External JavaScript loading can fail catastrophically, breaking functionality and user experience. Learn why mobile networks cause third-party script failures and discover simple defensive coding techniques to gracefully handle missing dependencies and protect your applications.

Todd Gardner's "JavaScript Forensics" talk from JSConfEU reveals expert techniques for tracking down web's most dangerous JavaScript errors. Learn real-world debugging strategies from years of production experience helping developers fix memory leaks, context loss, and jank.

Sourcemaps are essential for debugging transpiled JavaScript, mapping minified code back to original ES6/JSX sources. Chrome and Firefox support them natively, while tools like TrackJS automatically apply sourcemaps to production error stack traces, showing actual source code instead of unreadabl...

TrackJS reveals the harsh reality: 39% of web page views experience JavaScript errors. This comprehensive report analyzes error patterns across browsers, frameworks, and identifies the "Big Five" most common JavaScript errors affecting applications globally.