onBeforeSetupMiddleware

Provides the ability to execute custom middleware prior to all other middleware internally within the server.

webpack.config.js

module.exports = {
  // ...
  devServer: {
    onBeforeSetupMiddleware: (devServer) => {
      devServer.app.get("/before/some/path", (_, response) => {
        response.send("before");
      });
    },
  },
};

To run this example use the following command:

npx webpack serve --open

What Should Happen

1. The script should open http://localhost:8080/ in your default browser.
2. You should see the text on the page itself change to read Success!.
3. Go to http://localhost:8080/before/some/path, you should see the text on the page itself change to read before.