How to set a node environment variable when runnig via webpack

Question

I am currently setting up testing with jest/puppeteer and want to make use of the process.env.HEADLESS environment variable of the default config of jest-puppeteer:

module.exports = {
    launch: {
        dumpio: true,
        headless: process.env.HEADLESS !== 'false'
        product: 'chrome'
    },
    browserContext: 'default',
}

I run my page via webpack and would like to create a different run configuration that does not use headless chrome:

"test": "webpack serve --config ./webpack.config.js --mode development --env testvisibly --devtool source-map",

I understand that I need to set this environment variable in NODE, but am currently only setting environment variables in webpack. Those it seems I cannot access in the puppeteer configuration.

What do I need to do, how do I need to write my script to

• run webpack
• also have a switch available in my configuration file to turn headless on/off
• I want to put this switch into the package.json -> scripts

Thanks a lot for your support.