Use ES6 library's ES5 module without compiling it on my own project with rollup

Question

I need to use an ES6 library (Luxon) and want to compile down the files to ES5, but Rollup adds the files as ES6.

The library has a special /build folder with different output formats.

How can I configure Rollup to make use of that instead of doing nothing with the library?

Answer 1

First of all, you have two options here:

• Either compiling the library on your project with Rollup and @rollup/plugin-babel
• Or referencing the /build directory of the package instead of the ES6 version of the package, using an alias with @rollup/plugin-alias

I'll go with the second approach because is the one you asked for:

1. Install the plugin npm i @rollup/plugin-alias
2. At rollup.config.js import it import alias from '@rollup/plugin-alias';
3. Finally, add it to plugins:

const path = require('path');
module.exports = {
  input: 'src/index.js',
  output: {
    dir: 'output',
    format: 'cjs'
  },
  plugins: [
    alias({
      entries: [
        { find: 'luxon', replacement: path.resolve(process.cwd(), 'node_modules/luxon/build') },

      ]
    })
  ]
};