Node.js v12 + ECMA Module

node-and-es6.md

Enable ES module support

Built-in way

Use --experimental-modules.

For example:

node --experimental-modules index.js

More simple way

First install esm.

npm i esm

And run node with -r esm option.

node -r esm index.js

This also resolves an issue where node requires file extension of an ES module.

Treat files as ES module

In package.json, filed type, two options: commonjs(default) or module

• If set to module: every .js files are treated as ES modules.
• If set to commonjs: files with .mjs extension are treated as ES moduels.

If you want to use both CommonJS and ES modules, do not set type to module.