css module `import * as` not work after upgrade to webpack5

Bug report

I had update webpack4 to webpack5, but some css module not work.

For example:

// ...
{
  test: /\.module\.css$/,
  use: [
    isEnvDevelopment && require.resolve('style-loader'), 
    isEnvProduction && require("mini-css-extract-plugin").loader, 
    {
      loader: 'css-loader',
      options: {
        importLoaders: 1,
        modules: {
          compileType: 'module',
          exportLocalsConvention: 'camelCase',
          localIdentName: '[name]_[local]_[hash:8]'
        },
        esModule: false
      }
    },
    // ... postcssLoader, 
    // ... lessLoader
  ].filter(Boolean)
}
// ...

/* xxx.module.css */
.root {
	color: #fff;
}

not work

• env
  • webpack@5.16.0
  • css-loader@5.0.1

// a.jsx
import * as styles from './xxx.module.css'
import ss from './xxx.module.css'

console.log(styles) //  Module {__esModule: true, Symbol(Symbol.toStringTag): "Module"}
console.log(ss) // {root: "[name]_root_[hash]"}

work

• env
  • webpack@4.35.0
  • css-loader@5.0.1

// a.jsx
import * as styles from './xxx.module.css'
import ss from './xxx.module.css'

console.log(styles) //  {root: "[name]_root_[hash]"}
console.log(ss) // {root: "[name]_root_[hash]"}

I had read change log, so, it’s because of tree-shaking? But i had set sideEffects: true, that not work.

What is the current behavior? If css imported by import * as xxx from '*.css', the style not work.

If the current behavior is a bug, please provide the steps to reproduce.

What is the expected behavior? import * as xxx from '*.css' work, likes webpack5

Other relevant information: webpack version: 5.16.0 Node.js version: 12.13.1 Operating System: macOS Mojave Additional tools:

[monic-shixi]

No problems on webpack side, if you need help please open an issue in css-loader and provide simple reproducible test repo

Ok, thanks for you response.

[alexander-akait]

No problems on webpack side, if you need help please open an issue in css-loader and provide simple reproducible test repo