Method loadConfig

packages/webpack-cli/src/webpack-cli.ts:2836–3420

(options: Options)

  }

  async loadConfig(options: Options) {
    const disableInterpret =
      typeof options.disableInterpret !== "undefined" && options.disableInterpret;

    const loadConfigByPath = async (
      configPath: string,
      argv: Argv = { env: {} },
    ): Promise<{ options: Configuration | MultiConfiguration; path: string }> => {
      let options: LoadableWebpackConfiguration | undefined;

      const isFileURL = configPath.startsWith("file://");

      try {
        const ext = path.extname(configPath).toLowerCase();
        const dataFormatLoader = DATA_FORMAT_LOADERS[ext];

        if (dataFormatLoader) {
          // Non-JavaScript formats cannot be `import(...)`ed, so parse them
          // directly and skip the doomed dynamic import attempt entirely.
          const configFilePath = isFileURL ? fileURLToPath(configPath) : path.resolve(configPath);
          let parser: Record<string, (source: string) => unknown>;

          try {
            // Resolve the parser from the configuration file's location (so it
            // is picked up from the user's project rather than from webpack-cli),
            // then load it asynchronously via `import(...)`.
            const parserPath = createRequire(configFilePath).resolve(dataFormatLoader.package);
            const parserModule = await import(pathToFileURL(parserPath).href);

            parser = (parserModule.default ?? parserModule) as Record<
              string,
              (source: string) => unknown
            >;
          } catch {
            this.logger.error(`Unable to load the '${configFilePath}' configuration file.`);
            this.logger.error(
              `Loading '${ext}' configuration files requires the '${dataFormatLoader.package}' package, which is not installed. Please install it, e.g. \`npm install --save-dev ${dataFormatLoader.package}\`.`,
            );
            process.exit(2);
          }

          // Reading/parsing errors propagate to the handler below, which
          // reports `Failed to load '<config>' config`.
          const source = await fs.promises.readFile(configFilePath, "utf8");

          options = parser[dataFormatLoader.method](source) as LoadableWebpackConfiguration;
        } else {
          let loadingError;

          try {
            options = // eslint-disable-next-line no-eval
              (await eval(`import("${isFileURL ? configPath : pathToFileURL(configPath)}")`))
                .default;
          } catch (err) {
            if (this.isValidationError(err) || process.env?.WEBPACK_CLI_FORCE_LOAD_ESM_CONFIG) {
              throw err;
            }