Minify also the HTML files

[lslezak]

Problem

• Another attempt to also minify the HTML files (the previous Use html-webpack-plugin for minifying HTML in production #680 did not work properly)
• This time use the html-minimizer-webpack-plugin

Testing

• Tested manually
  • Running the development server locally (npm run server), I also tested Hot Module Replacement feature by editing some .jsx file
  • Building the production code (NODE_ENV=production npm run build) and copying the dist/* files to a testing machine
  • Building the development code (NODE_ENV=development npm run build && gzip dist/index.*) and copying the dist/* files to a testing machine

In all cases it worked fine. 😇

Notes

• That reactRefreshSetup should not be needed anymore, I haven't found any reference to it in the documentation.

[imobachgs]

I tested the code and it works for me too. However, as we do not have that much HTML code, the main change is that the reactRefreshSetup* files are missing:

Before:

4,0K    dist/favicon.svg
888K    dist/fonts
768K    dist/index.css
1,1M    dist/index.css.map
4,0K    dist/index.html
9,5M    dist/index.js
9,1M    dist/index.js.map
4,0K    dist/manifest.json
4,0K    dist/po.cs.js
84K     dist/reactRefreshSetup.js
68K     dist/reactRefreshSetup.js.map

After:

4,0K    dist/favicon.svg
888K    dist/fonts
768K    dist/index.css
1,1M    dist/index.css.map
4,0K    dist/index.html
9,5M    dist/index.js
9,1M    dist/index.js.map
4,0K    dist/manifest.json
4,0K    dist/po.cs.js

[lslezak]

That missing reactRefreshSetup.js is fine and IMHO it is a good idea to remove it.

• This file should not be distributed in production builds (as it is so far). If you try it loading in the production code you will get "React Refresh runtime should not be included in the production bundle" error
• I haven't found any reference to that file in it's documentation, the setup instructions do not mention that file at all
• The built index.js file includes that file in the development mode (grep ReactRefreshEntry.js dist/index.js)
• The hot module replacement still works fine without it

My guess is that it was probably needed in some older react-refresh version or without using the react-refresh-webpack-plugin...