old_contents: module.exports = {
    presets: [
      [
        '@babel/preset-env',
        {
          modules: false,
          targets: {
            browsers: [
              '> 1%',
              'last 2 versions',
              'not ie <= 8',
            ],
          },
        },
      ],
    ],
    comments: false,
    env: {
      test: {
        presets: [
          '@babel/preset-env',
        ],
      },
    },
  };
  
new_contents: module.exports = {
    presets: [
      [
        '@babel/preset-env',
        {
          modules: false,
          targets: {
            browsers: [
              '> 1%',
              'last 2 versions',
              'not ie <= 8',
            ],
          },
        },
      ],
    ],
    comments: false,
    env: {
      test: {
        presets: [
          [
            '@babel/preset-env',
            {
              targets: {
                node: 'current',
              },
            },
          ],
        ],
      },
    },
  };
  
subject: enable proper code transpiling during test