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CJS, ESM, WTF?? The History of JavaScript Modules

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  • Javascript
  • NodeJS
  • CommonJS
  • ES Modules

Writing modular code in JavaScript, it's a breeze since ECMAScript Modules (ESM) were implemented in browsers in 2018, right? ✨

If only this statement could be true... Unfortunately, for most developers, we still have to jam together two modules systems: CommonJS (CJS) and ESM. If both formats look alike on paper, their structural differences make them very difficult to use together, on the client as on the server. And what's more, you also have to transpile your modules, package them, test them... What was supposed to be child's play is becoming hellish!

(Re)discover with me the birth of the two formats and how they work under the hood. We'll see together how they came to be, how to use them and make them work in every context! After seeing this talk, modular code in JavaScript will lose all mystery to your eyes!