Is it possible to use ES6 modules in Mocha tests?

Question

ES6, Windows 10 x64, Node.js 8.6.0, Mocha 3.5.3

Is it possible to use ES6 modules in Mocha tests? I have the problems with export and import ke

Answer 1

It's possible with Babel and Browserfy https://drublic.de/blog/es6-modules-using-browserify-mocha/

Answer 2

Mocha has support for ESM from version 7.1.0 onward (release: Feb. 26, 2020).

This requires Node 12.11.0 or higher, and is subject to the current restrictions/limitations of using modules in Node:

• Either you must use .mjs file extensions for source files that use ES modules, or you must have "type": "module" in your package.json
• You can't use named imports when importing from CommonJS modules

And so on.

Another option is to use the esm package, which is not subject to the above limitations:

mocha -r esm

My personal experience as of yet is that trying to take advantage of Mocha's new, inherent ESM support is still a considerable burden, but using the esm package is quite seamless.