Add Support for 'sass-embedded'

[Pekes317]

Describe the feature you'd like to request

I would like to be able to use sass-embedded to compile my SCSS / SASS files.

Describe the solution you'd like

It looks like the sass-loader started support as of 12.6.0 so it would seem that just updating to that that version of the loader and probably adding it as an optional peer dependency.

Describe alternatives you've considered

Not sure of other alternatives.

[jakubriedl]

This is important because sass(dart) package is super slow on bigger codebases and node-sass is deprecated. sass-embedded is fastest of these 3 and fully supported.
In our builds we estimate that 70-80% of build time is spent on sass so making it faster is really big deal.

[joostmeijles]

Is it possible to use a custom configured sass-loader in NextJs config as workaround?

[joostmeijles]

Got it working using:

webpack(config) {
  ...

  for (const rule of config.module.rules) {
    if (rule.oneOf) {
      for (const oneOfRule of rule.oneOf) {
        if (oneOfRule.use && Array.isArray(oneOfRule.use)) {
          for (const use of oneOfRule.use) {
            if (use.loader && use.loader.includes('sass')) {
              use.loader = require.resolve('sass-loader');
              use.options.implementation = require.resolve('sass-embedded');
            }
          }
        }
      }
    }
  }

  ...
}

[joostmeijles]

PR to add sass-embedded support: #64577