code: function diff () {
    const files = getConfigFiles()
  
    debug('diff files: %o', files)
  
    const output = []
  
    files.forEach(f => {
      const result = jsDiff.structuredPatch(f[0].name, f[1].name, f[0].content, f[1].content)
  
      debug('diff result: %o', result)
  
      output.push('-------------------------------------------------\n')
      // eslint-disable-next-line max-len
      output.push(`diff ${chalk.blue(result.newFileName)} ${chalk.blue(result.oldFileName)}\n`)
      output.push('-------------------------------------------------\n')
  
      result.hunks.forEach(hunk => {
        fillLineNumber(hunk)
  
        const lines = hunk.lines.map(line => {
          if (line.startsWith('+')) {
            return chalk.green(line)
          }
          if (line.startsWith('-')) {
            return chalk.red(line)
          }
          return line
        })
  
        output.push(lines.join('\n'))
        output.push('\n')
      })
  
      output.push('\n')
    })
  
    console.log(output.join(''))
  }
docs: 执行 diff
  
  @returns {void}