hmr: false does not disable Hot Module Replacement

[thedanbob]

Starting with version 4, webpack-dev-server defaults to Hot Module Replacement enabled:
https://github.com/webpack/webpack-dev-server/blob/540c43852ea33f9cb18820e1cef05d5ddb86cc3e/CHANGELOG.md?plain=1#L561
https://github.com/webpack/webpack-dev-server/blob/540c43852ea33f9cb18820e1cef05d5ddb86cc3e/lib/Server.js#L1081

Shakapacker assumes the default is disabled: If hmr: true the --hot flag gets added to the webpack-dev-server command, but hmr: false does nothing. To actually disable HMR you must add hot: false to shakapacker.yml or the --no-hot command line flag.

[justin808]

@thedanbob good find. Any chance that you can submit a PR to resolve this?

[thedanbob]

Sure thing, I'll work on that later today.