es-modules.md

Using ES modules in AVA

Translations: Français

As of Node.js 13, ECMAScript modules are natively supported in Node.js itself. AVA does not quite support them yet, but we're close.

For the time being, AVA does select test files with the .mjs extension, however it refuses to load them. Similarly the package.json "type": "module" field is recognized, but if set AVA will refuse to load test files with the .js extension.

For now, your best bet is to use the esm package. Make sure to use the .js extension and do not set "type": "module" in package.json.

Here's how you get it working with AVA.

First, install esm:

$ npm install esm

Configure it in your package.json or ava.config.* file, and add it to AVA's "require" option as well. Make sure to add it as the first item.

package.json:

{
	"ava": {
		"require": [
			"esm"
		]
	}
}

You can now use native ES modules with AVA:

// sum.js
export default function sum(a, b) {
	return a + b;
};

// test.js
const test = require('ava');
const sum = require('./sum');

test('2 + 2 = 4', t => {
	t.is(sum(2, 2), 4);
});