Class WebpackFileManager

src/utils.js:82–279

  });

  class WebpackFileManager extends implementation.FileManager {
    /**
     * @param {string} filename filename
     * @returns {boolean} true when filename is supported, otherwise false
     */
    supports(filename) {
      if (filename[0] === "/" || IS_NATIVE_WIN32_PATH.test(filename)) {
        return true;
      }

      if (this.isPathAbsolute(filename)) {
        return false;
      }

      return true;
    }

    // Sync loading is used by `data-uri()` and any custom Less function
    // (including those installed via `@plugin`). Webpack doesn't expose a
    // sync resolver, so we fulfil the sync read by delegating to Less's
    // default file manager (which can only handle native filesystem paths)
    // and, in parallel, kick off an async webpack resolve so the loaded
    // file is tracked as a webpack file dependency. Without this, webpack's
    // persistent cache won't invalidate when a sync-loaded file changes.
    // See https://github.com/webpack/less-loader/issues/492.
    /**
     * @returns {boolean} true when support sync, otherwise false
     */
    supportsSync() {
      return true;
    }

    /**
     * @param {string} filename filename
     * @param {string} currentDirectory current directory
     * @param {LoadFileOptions} options options
     * @param {Environment} environment environment
     * @returns {LoadFileResult} loaded file
     */
    loadFileSync(filename, currentDirectory, options, environment) {
      // The default Less `loadFileSync` internally dispatches to
      // `this.loadFile` with `options.syncImport = true`. Because we
      // override `loadFile` (async), dynamic dispatch would land back in
      // our async version and break the sync contract. Invoke the parent
      // `loadFile` directly with the sync flag instead.
      // @ts-expect-error bad types in less
      const result = /** @type {LoadFileResult} */ (
        super.loadFile(
          filename,
          currentDirectory,
          { ...options, syncImport: true },
          environment,
        )
      );

      if (result && result.filename) {
        loaderContext.addDependency(
          path.normalize(