es-dev-commonjs-transformer


CommonJS Module transformer for the es-dev-server. It converts modules cjs -> esm format. Uses Rollup commonjs plugin under the hood.

``js
// In
const a = require('dep');
...
module.exports = a;
`
`js
// Out
import a from 'dep';
...
export default a;
`

General Usage

`js
//es-dev-server.config.js

import cjsTransformer from 'es-dev-commonjs-transformer';

module.exports = {
responseTransformers: [
cjsTransformer(/ Exclude Paths Array / [
'/node_modules/@open-wc//*',
...
])
]
}
`

OpenWC Karma Testing Setup

The Open-wc karma setup requires you to exlude some paths from being processed by the cjs transformer.
The following excludes seems to have worked for me.

`js
//karma.conf.ts

const cjsTransformer = require('es-dev-commonjs-transformer');
const { createDefaultConfig } = require('@open-wc/testing-karma');

module.exports = config => {
let defaultConfig = createDefaultConfig(config);

...

esm: {
responseTransformers: [
cjsTransformer([
...defaultConfig.esm.babelModernExclude,
'/node_modules/@open-wc//*',
'/node_modules/chai-dom//*',
'/node_modules/sinon-chai//*'
])
]
}
}
``