Skip to content
Swizec Teller - a geek with a hatswizec.com

MacOS filesystem's annoying little quirk

The filesystem on your shiny expensive laptop is case insensitive. Did you know?

I know, but I always forget. Your code looks like it works. It compiles, the tests all pass, you can run it, and you can play with it. Then you push to production, and it breaks. Sometimes in the build step, sometimes as late as runtime, but inevitably, it breaks.

This is the one situation where I envy all my friends who work on Linux, maybe even Windows. They've never had to deal with this shit.

MacOS → case insensitive. Linux → case sensitive.

You thought working with JavaScript would get you away from these low level concerns, didn't you? Yeah, me too.

Here's why you should care. Watch this gif:

Make a file called ALLCAPS.js, read it as allcaps.js, and MacOS doesn't even bat an eye. Then you put the same code on a Linux server, and all hell breaks loose.

¯\_(ツ)_

This quirk shows up when you least expect it – innocent camelCAse typos. Your code works, git status says everything's merged, and the typo goes unnoticed until it's too late.

I'm too embarrassed to say how much time I've lost to this quirk over the years. So I won't.

Here's to hoping I'll stop forgetting now. ?

Did you enjoy this article?

Published on August 23rd, 2016 in Opinions, Personal, Technical

Learned something new?
Want to become a high value JavaScript expert?

Here's how it works 👇

Leave your email and I'll send you an Interactive Modern JavaScript Cheatsheet 📖right away. After that you'll get thoughtfully written emails every week about React, JavaScript, and your career. Lessons learned over my 20 years in the industry working with companies ranging from tiny startups to Fortune5 behemoths.

Start with an interactive cheatsheet 📖

Then get thoughtful letters 💌 on mindsets, tactics, and technical skills for your career.

"Man, love your simple writing! Yours is the only email I open from marketers and only blog that I give a fuck to read & scroll till the end. And wow always take away lessons with me. Inspiring! And very relatable. 👌"

~ Ashish Kumar

Join over 10,000 engineers just like you already improving their careers with my letters, workshops, courses, and talks. ✌️

Have a burning question that you think I can answer? I don't have all of the answers, but I have some! Hit me up on twitter or book a 30min ama for in-depth help.

Ready to Stop copy pasting D3 examples and create data visualizations of your own?  Learn how to build scalable dataviz components your whole team can understand with React for Data Visualization

Curious about Serverless and the modern backend? Check out Serverless Handbook, modern backend for the frontend engineer.

Ready to learn how it all fits together and build a modern webapp from scratch? Learn how to launch a webapp and make your first 💰 on the side with ServerlessReact.Dev

Want to brush up on your modern JavaScript syntax? Check out my interactive cheatsheet: es6cheatsheet.com

By the way, just in case no one has told you it yet today: I love and appreciate you for who you are ❤️