accounts-frontend/webpack-utils/intl-loader.js

function transform(src, modulePath, rootContext) {
  const json = JSON.parse(src);

  const moduleId = modulePath
    .replace(rootContext, '')
    // TODO: can't find the way to strip out this path part programmatically
    // this is a directory from resolve.modules config
    // may be this may work: .replace(this._compiler.options.resolve.root, '')
    .replace('src/', '')
    .replace(/^\/|\/$/g, '')
    .replace(/\//g, '.');

  return JSON.stringify(
    Object.keys(json).reduce(
      (translations, key) => ({
        ...translations,
        [key]: {
          id: `${moduleId}.${key}`,
          defaultMessage: json[key],
        },
      }),
      {},
    ),
  );
}

module.exports = function(content) {
  this.cacheable && this.cacheable();

  content = transform(content, this.context, this.rootContext);

  return `import { defineMessages } from 'react-intl';

export default defineMessages(${content})`;
};

module.exports.transform = transform;