A laravel mix extension that allow us to get the webpack config as a string. So we do whatever we want with it.
Including writing to files. Unlike .dump() component that only print to console.

Also the extension does patch .dump() and dumpWebpackConfig() to take a callback that return the config.

// without dumping the config
mix.getWebpackConfig((config, stringify) => {
  fs.writeFileSync('webpackConfig.output.js', stringify(config));
});

// with dumping the config (patched)
mix.dump((config, stringify) => {
  fs.writeFileSync('webpackConfig.output.js', stringify(config));
});

// or
mix.dumpWebpackConfig((config, stringify) => {
  fs.writeFileSync('webpackConfig.output.js', stringify(config));
});

npmjs: https://www.npmjs.com/package/laravel-mix-webpack-config
laravel-mix extensions: https://laravel-mix.com/extensions/webpack-config

I suggest using pnpm

pnpm

pnpm add laravel-mix-webpack-config -D

npm

npm install laravel-mix-webpack-config -D

yarn

yarn add laravel-mix-webpack-config -D

const mix = require('laravel-mix');
const fs = require('fs');

require('laravel-mix-webpack-config');

const public_dir = 'public';

mix
  .setPublicPath(`${public_dir}`)
  .js(`${public_dir}/src/app.js`, `${public_dir}/dist`)
  .vue()
  .version([`${public_dir}/src/index.js`])
  .extract(['vue'], `dist/v.js`)
  .getWebpackConfig((config, stringify) => {
    fs.writeFileSync('webpackConfig.output.js', stringify(config));
  });

You can see it allow us to write the config to a file:

mix.getWebpackConfig((config, stringify) => {
  fs.writeFileSync('webpackConfig.output.js', stringify(config));
});

Take a callback as a param. With signature:

(
  webpackConfig: WebpackDomain.Configuration,
  stringify: DumpWebpackConfig['circularStringify'],
) => void;

webpackConfig: the final webpack config as an object.
stringify: Same circular stringify function that is implemented in the Dump component (when you use .dump()). So you expect to get the same string as the one used by .dump() logging component.

Giving this structure. You can do whatever you want with the object. Including something involving stringify like writing to a file.

dump() and dumpWebpackConfig() are patched. So they take the same callback. With the same signature. They keep working as before. Plus that callback as an extra part of the patch.
dump(), dumpWebpackConfig() => dump the config to the console + can get the config as well to do something with it. Like writing to a file.

You can use any of the bellow Aliases in place of getWebpackConfig().

.getWebpackConfig()
.listenWebpackConfig()
.lwc()