./helpers/hoistLoaderIfOne.js

hoistLoaderIfOne.js

import _ from 'lodash';

/**
 * @example
 *
 * Turns this:
 *
 * hoistLoaderIfOne({
 *   test: /\.js$/,
 *   loaders: [
 *     {
 *       loader: 'babel',
 *     }
 *   ]
 * })
 *
 * into this:
 * {
 *   test: /\.js$/
 *   loader: 'babel'
 * }
 *
 * @param {(string|Object)[]|undefined} loaders
 * @param {Object} topLoader
 * @returns {Object}
 */
export default function hoistLoaderIfOne({ loaders, ...topLoader }) {
  if (loaders && loaders.length === 1) {
    const firstLoader = loaders[0];

    if (_.isString(firstLoader)) {
      return {
        ...topLoader,
        loader: firstLoader,
      };
    }

    return {
      ...topLoader,
      ...firstLoader,
    };
  }

  return {
    ...topLoader,
    loaders,
  };
}