DEV Community 👩‍💻👨‍💻

Michael Crenshaw
Michael Crenshaw

Posted on

Don't forget to ask Babel to compile .mjs files

I spent several hours trying to understand why Babel wasn't transpiling const statements in Jeremy Wagner's yall.js library.

It was because the actual filename is yall.mjs, and I hadn't configured Babel to handle that extension.

The correct test configuration ended up being as follows:

test: /\.(m?j|t)s$/,
Enter fullscreen mode Exit fullscreen mode

Or, if you don't need TypeScript:

test: /\.m?js$/,
Enter fullscreen mode Exit fullscreen mode

Suffer me not to ponder the ills and advantages of the .mjs extension. That's for smarter people.

But since some folks do use that extension, it's probably worth updating your Babel config and related documentation/tutorials.

Top comments (0)

🌚 Life is too short to browse without dark mode