squid-js/plugins/add-vendors-plugin.js

const { ConcatSource } = require('webpack-sources')

module.exports = class AddVendorsPlugin {
    constructor(base) {
        this.base = base
    }

    apply(compiler) {
        compiler.hooks.emit.tapAsync(`AddVendorsPlugin ${this.base}`, (compilation, callback) => {
            const main = compilation.assets[`main.${this.base}`]
            const mainMap = compilation.assets[`main.${this.base}.map`]
            const vendor = compilation.assets[`vendors.${this.base}`]

            if (main && vendor) {
                const compiledAsset = new ConcatSource(main.children[0])
                compiledAsset.add(vendor)
                compiledAsset.add(main.children[1])
                compilation.assets = {}
                compilation.assets[this.base] = compiledAsset
            } else if (main && mainMap) {
                compilation.assets = {}
                compilation.assets[this.base] = main
                compilation.assets[`${this.base}.map`] = mainMap
            }
            callback()
        })
    }
}