Babel compiles with Webpack but not with Jest - node.js

Question

I'm trying to setup Jest to work with my ES6 project using Babel with env preset. The code compiles and works with Webpack but not with Jest. Issue seems to be with transpiling code from inside of node_modules.
package.json (yarn) :
{
"name": "generative-toolbox",
"version": "0.0.1",
"main": "toolbox.js",
"repository": "git#bitbucket.org:yojeek/generative-toolbox.git",
"author": "msamoylov <antiplaka#gmail.com>",
"license": "MIT",
"private": true,
"scripts": {
"build": "yarn webpack --config webpack.config.js",
"test": "jest --debug"
},
"devDependencies": {
"babel-jest": "^22.4.3",
"jest": "^22.4.3",
"regenerator-runtime": "^0.11.1",
"webpack-cli": "^2.1.2"
},
"dependencies": {
"babel-core": "^6.26.3",
"babel-loader": "^7.1.4",
"babel-preset-env": "^1.6.1",
"babel-register": "^6.26.0",
"dat.gui": "^0.7.1",
"enumify": "^1.0.4",
"event-pubsub": "^4.3.0",
"webpack": "^4.6.0"
},
"babel": {
"presets": [
["env"],
"stage-2"
],
"env": {
"test": {
"presets": [
["env", {
"targets": {
"node": "9.4.0"
},
"debug": true
}],
"stage-2"
]
}
}
}
}
webpack.config.js :
var path = require("path");
module.exports = {
entry: "./toolbox.js",
mode: 'development',
output: {
path: path.resolve(__dirname, "dist"),
filename: "generative.toolbox.js",
publicPath: '/dist/',
library : "GenT"
},
module: {
rules: [
{
test: /\.js$/,
exclude: /(node_modules|bower_components)/,
use: {
loader: 'babel-loader'
}
}
]
}
}
Definitions from toolbox.js :
import EventPubSub from 'event-pubsub'
class GUI {
gui
config
values
constructor() {
// some valid code
}
}
class MIDI extends EventPubSub {
midi
constructor() {
super()
// some valid code down there
}
}
test.js :
import {GUI, MIDI} from './toolbox.js'
test('gui sanity', () => { // <--- pass
let gui = new GUI()
expect(gui).toBeTruthy()
});
test('midi sanity', () => { // <--- fail
let midi = new MIDI()
expect(midi).toBeTruthy()
});
Test fails with following result :
TypeError: Class constructor EventPubSub cannot be invoked without 'new'
99 | midi
100 |
> 101 | constructor() {
102 | super()
103 |
104 | // request MIDI access
at new MIDI (toolbox.js:101:17)
at Object.<anonymous> (test.js:15:14)

Answer 1

So, because I want to extend ES6 Class from within node_modules I had to explicitly exclude it in jest config :
"jest": {
"transformIgnorePatterns": [
"/node_modules/(?!event-pubsub).+\\.js$"
]
}
That way the module will be imported to my test as it is (not transpiled).