code: function findConfig(file) {
    if (file) {
      // Custom config location
  
      const configFilepath = file[0] === '/'? file : path.join(process.cwd(), file);
      if (!fs.existsSync(configFilepath)) {
        throw new DvhbWebpackError('DvhbWebpack config not found: ' + configFilepath + '.');
      }
  
      return configFilepath;
    }
  
    // Search config file in all parent directories
  
    let configDir;
    try {
      configDir = findup.sync(__dirname, CONFIG_FILENAME);
    }
    catch (exception) {
      throw new DvhbWebpackError('DvhbWebpack config not found: ' + CONFIG_FILENAME + '.');
    }
  
    return path.join(configDir, CONFIG_FILENAME);
  }
docs: Find config file: use file specified in the command line or try to find up the file tree.
  
  @param {Object} [file] File name.
  @return {string} Config absolute file path.