har-express

First be sure to know what is HAR file reading wikipedia.

This package expose a CLI to create an HTTP mock server and a library API to integrate it in webpack devServer

Use case

So you have an HAR file ? You can either:

• configure webpack to use the har file directly
• start a server using the CLI

using only webpack

So in your webpack.config.dev.js file you can do the following:

const har = require('har-express');

if (process.env.HAR) {
	devServer.before = app => {
		app.use(har.getMiddleware(process.env.HAR));
	};
} else {
    // fallback for dev in your proxy to the real backend
	devServer.proxy = {
		'/api': process.env.API_URL || 'http://localhost:8000',
	};
}

module.exports = {
	devServer,
};

then you can start your project using

HAR='./use-case.har' yarn start

Using CLI

In the context your webpack config use API_URL env to configure the proxy just do

API_URL=http://localhost:8000 yarn start
har-express -p 8000 ./use-case.har