[Feature]: Mock all files with certain extension

[akcyp]

What problem does this feature solve?

In Jest it's common to create following configuration to ignore / mock files with certain file extensions (css, less, scss, png, etc.).

{
  "moduleNameMapper": {
    "\\.(css|less|scss)$": "<rootDir>/src/Mocks/styleMock.js" // module.exports = {}
  }
}

It seems that in the case of rstest this is not so easy to achieve without a custom plugin.

What does the proposed API look like?

Support regexpes in resolve.alias or create native "ignore" plugin that will override files content with empty export.

[9aoy]

This can be achieved using rspack NormalModuleReplacementPlugin.

export default defineConfig({
  tools: {
    rspack: (config, { rspack}) => {
      config.plugins.push(
       new rspack.NormalModuleReplacementPlugin(/\.(css|less|scss)/, require.resolve('./src/Mocks/styleMock.js'))
      );
    }
  }
});

[akcyp]

Thanks for the reply.
I didn't know about this plugin, maybe it would be worth considering adding this information to the migration guide from Jest?
I'm closing this thread.

[chenjiahan]

I agree that it would be helpful to include this method in the Jest migration guide or offer a more direct solution. I'll reopen this issue so we can follow up on it.

[9aoy]

+1. The NormalModuleReplacementPlugin is a bit difficult for users to use.
Perhaps it would be simpler for rstest or rsbuild to provide a configuration option similar to resolve.moduleNameMapper.