Function getModernWebpackImporter

src/utils.js:556–637

* @param {LoaderContext} loaderContext loader context * @returns {Importer} the modern webpack importer

(loaderContext)

 * @returns {Importer} the modern webpack importer
 */
function getModernWebpackImporter(loaderContext) {
  const resolve = getWebpackResolver(loaderContext.getResolve);

  return {
    /**
     * @param {string} originalUrl original url
     * @param {{ fromImport: boolean, containingUrl: URL | null }} context context
     * @returns {Promise<URL | null>} canonicalized URL
     */
    async canonicalize(originalUrl, context) {
      const { fromImport } = context;
      const prev = context.containingUrl
        ? url.fileURLToPath(context.containingUrl.toString())
        : loaderContext.resourcePath;

      let result;

      try {
        result = await resolve(prev, originalUrl, fromImport);
      } catch {
        // If no stylesheets are found, the importer should return null.
        return null;
      }

      loaderContext.addDependency(path.normalize(result));

      return url.pathToFileURL(result);
    },
    /**
     * @param {URL} canonicalUrl canonical url
     * @returns {Promise<{ contents: string, syntax: "scss" | "indented" | "css", sourceMapUrl: URL } | null>} load result
     */
    async load(canonicalUrl) {
      const ext = path.extname(canonicalUrl.pathname);

      /** @type {"scss" | "indented" | "css"} */
      let syntax;

      if (ext && ext.toLowerCase() === ".scss") {
        syntax = "scss";
      } else if (ext && ext.toLowerCase() === ".sass") {
        syntax = "indented";
      } else if (ext && ext.toLowerCase() === ".css") {
        syntax = "css";
      } else {
        // Fallback to default value
        syntax = "scss";
      }

      try {
        const contents = /** @type {string} */ (
          await new Promise((resolve, reject) => {
            // Old version of `enhanced-resolve` supports only path as a string
            // TODO simplify in the next major release and pass URL
            const canonicalPath = url.fileURLToPath(canonicalUrl);

            loaderContext.fs.readFile(
              canonicalPath,