dev-server: hot

4 hot and hotOnly change is: hot: [Boolean | ‘only’]

dev-server: hot <=> HotModuleReplacementPlugin

HotModuleReplacementPlugin don’t need to manually, introducing in dev – after open the hot server will find HotModuleReplacementPlugin instance, in the plugins found no will be instantiated:

Github.com/webpack/web…

Some configurations of Webpack 5 and 4 have breakChange. If you encounter error, you’d better go to the issue of Webpack to find it