Update postcss-loader to v4

[feimosi]

postcss-loader@4 adds support for postcss@8
https://github.com/webpack-contrib/postcss-loader/releases
There are some breaking changes that have to be addressed.

[honghainguyen777]

Dear @feimosi,

Have you found a way to add the postcss@8 support to react-app-rewire-postcss? I am currently having trouble with ABC package requires PostCSS 8. Unfortunately, I have a project that uses another project as a submodule. The submodule project has the new version of tailwindcss, postcss, and postcss-import. Therefore, my project is broken now.

Best wishes,
Hai

[feimosi]

@honghainguyen777 I haven't found any solution to this. I no longer use react-app-rewired.

[honghainguyen777]

@honghainguyen777 I haven't found any solution to this. I no longer use react-app-rewired.

Hi @feimosi, could you insight me what is your alternatives for react-app-rewired?

[feimosi]

I've been successfully using craco. However in my current project we use node-sass, so I can't help with postCSS configuration, but it should work out of the box.