ngcp-csc-ui/test/loaders/jest-loader.js

const fs = require('fs')
const loaderUtils = require('loader-utils')
const path = require('path')

module.exports = async function (source) {
    const options = loaderUtils.getOptions(this)

    const filename = path.parse(this.resourcePath).name

    const extension = (options && options.extension) || '_jest.spec.js'
    const dir = `${this.context}/__tests__`
    console.log(`Created test file: ${filename}`)
    if (!fs.existsSync(dir)) {
        fs.mkdirSync(dir)
    }
    const code = source.replace(/\n{2,}/, '')
    const dest = `${dir}/${filename}${extension}`
    fs.writeFileSync(dest, code)
    return `<!-- Created test file: ${filename} -->`
}