Steps to reproduce webpack-dev-server bug #1193:

1. Install and start webpack-dev-server (WDS):

npm install
npm start

Now a webpack entry with WDS client script inside is situated on http://localhost:3000/main.js

2. Go to HTTP page, containing

<script src="http://localhost:3000/main.js"></script>

As you can see, WDS client successfully connected to WDS server.

3. Go to the page via HTTPS.

WDS client cannot connect to WDS server.

The reason is that WDS client tries to connect to non-existent endpoint https://localhost:3000/sockjs-node. But it should connect to http://localhost:3000/sockjs-node (The difference is in protocol.)