It Works on My Machine™

December 17, 2024

It Works on My Machine™

Ah, the four words that strike fear into the hearts of developers everywhere. Let's explore this timeless phenomenon that's been haunting code reviews since the dawn of time.

The Natural Habitat

Picture this: You've just pushed your code. CI is green. Tests pass. Life is good. Then:

QA: "The app crashes on startup"
You: "That's impossible, works on my machine"
QA: "Well, I'm looking at a black screen"
You: "BUT IT WORKS ON MY MACHINE!"

The Developer's Checklist

  • ✅ Works on my local
  • ✅ Works in dev environment
  • ✅ Works in my dreams
  • ❌ Works in production

The Investigation

// The code you wrote
const config = {
  port: 3000,
  dbPath: 'C:/Users/YourName/perfect/setup/db',
  nodeModules: 'definitely/installed/correctly'
};

// What production actually sees
const config = {
  port: undefined,
  dbPath: '404_not_found',
  nodeModules: 'what_node_modules?'
};

The Classic Solutions

  1. "Have you tried clearing your cache?"
  2. "Let me push a quick hotfix" (narrator: it was not quick)
  3. "Must be a Docker issue"
  4. The nuclear option: "Works on my machine, let's ship my machine"

The Real Fix

After 6 hours of debugging:

- const port = process.env.PORT;
+ const port = process.env.PORT || 3000;

Conclusion

Remember: "Works on my machine" is not a deployment strategy. Though if anyone's interested, I am working on a startup that ships developer machines to production environments. Currently seeking Series A funding.

P.S. If this post doesn't display correctly, try clearing your cache. Works on my machine! 🤷‍♂️