text: 'use strict';
  
  const crypto = require('crypto');
  
  const macroCheck = new RegExp('[./]macro');
  
  module.exports = () => ({
    // This function transforms the Babel configuration on a per-file basis
    config(config, { source }) {
      // Babel Macros are notoriously hard to cache, so they shouldn't be
      // https://github.com/babel/babel/issues/8497
      // We naively detect macros using their package suffix and add a random token
      // to the caller, a valid option accepted by Babel, to compose a one-time
      // cacheIdentifier for the file. We cannot tune the loader options on a per
      // file basis.
      if (macroCheck.test(source)) {
        return {
          ...config.options,
          caller: {
            ...config.options.caller,
            craInvalidationToken: crypto.randomBytes(32).toString('hex'),
          },
        };
      }
  
      return config.options;
    },
  });
  