code: function createUnifiedDiff({ actual, expected }) {
    return diff.createPatch('string', actual, expected)
      .split('\n')
      .splice(4)
      .map(line => {
        if (line.match(/@@/)) {
          return null;
        }
        if (line.match(/\\ No newline/)) {
          return null;
        }
        return line.replace(/^(-|\+)/, '$1 ');
      })
      .filter(line => typeof line !== 'undefined' && line !== null)
      .join('\n');
  }
docs: Create a unified diff between two strings
  
  @param {Error}  err          Error object
  @param {string} err.actual   Actual result returned
  @param {string} err.expected Result expected
  
  @return {string} diff