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🧠 How to Know You Have JavaScript Issues (Before Your Users Riot)

#javascriptsucks #code #learn #webdev

🧠 How to Know You Have JavaScript Issues (Before Your Users Riot)

JavaScript is sneaky. Everything looks fine... until it explodes at runtime 💥. Here's how to spot the red flags early and fix them before they become chaos.

1. 🚨 Your Console Looks Like a Horror Movie 


// Example:
Uncaught TypeError: Cannot read properties of undefined
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🧠 If you're seeing red messages in the console — trust me — you're doing something wrong. Debug it before pushing to production.

2. 🧩 Things Only Work Sometimes (aka The Schrodinger Bug)

Random button clicks work sometimes, or a function behaves weirdly depending on what page you're on?


if (user = "admin") {   // oops, assignment instead of comparison!
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🧠 If your app is haunted, check your conditions and scope handling.

3. 🦥 Page Loads Are Suspiciously Slow

Using too many await calls or heavy computations in the main thread?


await getUserData();
await getPosts();
await getNotifications();
// Sluggish mess
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🧠 Time to learn about Promise.all() and non-blocking rendering.

4. 🧟‍♂️ Memory Leaks and Dead Listeners

When your browser tab eats 2GB RAM and your PC starts heating up...


window.addEventListener("resize", myHandler); // added 100x, never removed
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🧠 Clean up your listeners and intervals with .removeEventListener() or clearInterval().

5. 🥴 You Can’t Reproduce the Bug… But the User Can

That one user says "it crashes every time", but everything's perfect for you.

🧠 This usually means:

  • You rely on user-specific data
  • You make assumptions (e.g., assuming localStorage always exists)
  • Your code is not cross-browser compatible

6. 📦 You Forgot to Import Something (Or Imported It Wrong) 


ReferenceError: React is not defined
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🧠 Make sure your imports are correct, and you're not mixing ESM and CommonJS without knowing what you're doing.

7. 🔄 Infinite Loops or Rerenders 


useEffect(() => {
  fetchData();
}, [data]); // oops, data changes on every render
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🧠 Be careful with dependencies in React hooks. Also... don’t forget to use a return function for cleanup!

✅ Conclusion: Red Flags to Watch For

  • Red console errors
  • Memory spikes
  • Weird re-renders
  • Random "undefined is not a function"
  • Users reporting strange stuff you can't reproduce

🔍 Use tools like:

  • Chrome DevTools
  • ESLint
  • Lighthouse
  • TypeScript (it yells at you before runtime)

Stay paranoid. Stay bug-free. 🐞💻

Javascript Sucks

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