describe('genDiff plain answer', () => {
  test('genDiffTree JSON vs plainAnswer', () => {
    const actual = genDiff('__tests__/__fixtures__/input/before.json',
      '__tests__/__fixtures__/input/after.json', 'plain');
    const expected = fs.readFileSync('__tests__/__fixtures__/answer/plainAnswer.txt', 'utf8').trim();