Feature request: allow passing path to sass config file

[jrencz]

First thing: thank you for following my suggestion and starting this project!

My use case:

As I mentioned described in jgranstrom/sass-extract-loader#2 I have custom importers and functions in sass and it's not possible to use this babel plugin without them because of sass errors.
Since babel doesn't allow babelrc.js (babel/babel/issues/4630) and node sass has no option to pass path to options instead of actual options the only way I see is to add options loader in the plugin

[jrencz]

I modified the source of plugin but there's an error I can't debug (probably somewhere inside node-sass binding)

My version of extractVariables:

const configs = new Map();

function extractVariables(absolutePath, compiledFiles, options) {
  let vars;
  if(compiledFiles[absolutePath]) {
    vars = compiledFiles[absolutePath];
  } else {
    if ('sassConfigPath' in options && !configs.has(options.sassConfigPath)) {
      configs.set(options.sassConfigPath, require(path.resolve(options.sassConfigPath)));
    }

    const loadedOptions = configs.get(options.sassConfigPath);

    vars = compiledFiles[absolutePath] = sassExtract.renderSync(Object.assign({}, options, loadedOptions, {file: absolutePath})).vars;
  }

  return vars;
}

{
  "plugins": [
    ["babel-plugin-sass-extract", {
      "sassConfigPath": "./sass.conf.js"
    }],
  ]
}

I went down to renderSync in sass-extrct. Code stops at:

var rendered = _nodeSass2.default.renderSync(compileOptions);

Wrapping it in try-catch doesn't help.

[jgranstrom]

@jrencz thank you for your contributions. I am currently looking into handling additional custom importers and passing functions through the plugins. The custom importers will initially need some more work in the sass-extract core library. Regarding the function passing issue I might add an alternative configuration method by having a sass-extract.config.js in the working directory of the plugins that can contain the functions.

[jrencz]

dedicated file seems reasonable

Going from there to expressing the path in plugin config via .babelrc is not far away