Sass imports from node_modules

[noahtallen]

Howdy! In sass, you can use sass-loader with Webpack to resolve Sass imports from node modules. This can look something like the following:

@import 'npm-package/stylesheet'

// etc

This should resolve to node_modules/npm-package/stylesheet.scss. Unfortunately, cabinet + sass-lookup doesn't quite handle this use case. You can get it to resolve using just cabinet, by passing node_modules as a directory, but dependency tree doesn't accept multiple directories in general, so that won't work for our use case. I was wondering what a good path would be towards implementing support.

A really naive implementation could be something like this as the lookup function for sass in cabinet.

function sassResolver(options) {
  let { directory } = options;
  if (typeof directory === 'string') {
    directory = [ directory ];
  }
  directory.push( 'node_modules' );
  return sassLookup({ ...options, directory })
}

This does work, but it wouldn't be able to handle different node_modules locations, such as in monorepos. One could also add a custom resolver like this: https://github.com/Automattic/wp-calypso/blob/6ef9f9278aaf368cd629ba69c33c4768dc7ea08d/bin/render-stylesheet.js#L16-L23. But I'm not sure where exactly to put that -- would the sass-lookup package be a good fit?

What are your thoughts?

[mrjoelkemp]

Hey @noahtallen! Thanks for the question and context. Seems like we could overhaul https://github.com/dependents/node-sass-lookup/blob/master/index.js and incorporate sass-loader or replace sass-lookup entirely with sass-loader (which is probably more to your suggestion). I'm open to either that satisfies existing tests and also passes new tests associated with your imports case above.

Happy to review a PR. Thanks again.