错误：评估失败：ReferenceError：req 未定义

Question

我有一个快速设置。由于某种原因，此函数无法识别 req：

router.post('/search', (req, res) => {
  ;(async (req, res) => { //req and res here are just parameters in function definition
    const browser = await puppeteer.launch()
    const page = await browser.newPage()
    await page.goto(`https://www.google.com/search?tbm=bks&q=%22this+is%22`)
    const result = await page.evaluate(() => {
      console.log('CLAUSESS:', req.body.clauses)
      const clauses = req.body.clauses
      return clauses.map(clause => clause.textContent)
    })
    result.join('\n')
    await browser.close()
    res.send(result)
  })(req,res); //This is where we call the function, so we need to pass the actual values here.
})

这是错误：

UnhandledPromiseRejectionWarning：未处理的承诺拒绝 （拒绝 id：1）：错误：评估失败：ReferenceError：req is 没有定义的 在:2:32

可能是什么原因？

Answer 1

快速路由处理器的返回值无关紧要，可以是async

router.post('/search', async (req, res, next) => {
  try {
    const browser = await puppeteer.launch()
    const page = await browser.newPage()
    await page.goto(`https://www.google.com/search?tbm=bks&q=%22this+is%22`)
    const result = await page.evaluate(() => {
      console.log('CLAUSESS:', req.body.clauses)
      const clauses = req.body.clauses
      return clauses.map(clause => clause.textContent)
    })
    result.join('\n')
    await browser.close()
    res.send(result)
  }
  catch (err) {
    next(err)
  }
})