Express验证程序错误：expressValidator不是函数

Question

我正在尝试安装和使用express-validator软件包。我已经安装了软件包版本（6.0.0），然后在server.js文件中，代码是：

const bodyParser = require('body-parser')
const expressValidator = require('express-validator')
const express = require('express')
const nunjucks = require('nunjucks')
const sessionInMemory = require('express-session')
const cookieParser = require('cookie-parser')

然后往下几行，我输入了以下内容：

const app = express()
const documentationApp = express()
app.use(expressValidator())

当服务器重新加载更改（使用nodemon）时，应用程序崩溃并显示：

TypeError：expressValidator不是函数

我的server.js文件中还有其他代码段，但是我去除了大部分与我无关的代码。

Console log for expressValidator:

{ oneOf: [Function: oneOf],
  buildSanitizeFunction: [Function: buildSanitizeFunction],
  sanitize: [Function],
  sanitizeBody: [Function],
  sanitizeCookie: [Function],
  sanitizeParam: [Function],
  sanitizeQuery: [Function],
  buildCheckFunction: [Function: buildCheckFunction],
  check: [Function],
  body: [Function],
  cookie: [Function],
  header: [Function],
  param: [Function],
  query: [Function],
  checkSchema: [Function: checkSchema],
  matchedData: [Function: matchedData],
  validationResult: { [Function] withDefaults: [Function: withDefaults] },
  Result: [Function: Result] }

Code for routes.js file:

router.get('/email-adress', function (req, res) {
  res.render('email-adress', { success: req.session.success, errors: req.session.errors })
  req.session.errors = null
})

router.post('/finished', function (req, res) {
  let email = req.body.email

  req.checkBody('email', 'Email required').isEmail()

  var errors = req.validationErrors()
  if (errors) {
    req.session.errors = errors
    req.session.success = false
    res.redirect('/email-adress')
  } else {
    req.session.success = true
    res.redirect('/finished')
  }
})

Answer 1

Express Validator 已经更新，现在不能这样使用了 这是使用 express 验证器的新方法

或者，您可以通过运行此命令保留以前的版本

npm uninstall express-validator
npm install express-validator@5.3.0

Answer 2

是的！即使我也有同样的问题。您可以通过在根文件夹中写入命令来更改版本。

命令：

npm install express-validator@5.3.1 --save-exact

Answer 3

//just pass the checking as middleware not in the callback
//see here I've just passed an array for checking as middleware
// as the middleware is an array therefore you can add multiple checks in the array
router.post("/", [check('email', "your custom error message").isEmail()], (req, res) => {

  const errors = validationResult(req);
  if (!errors.isEmpty()) {
   res.render('errorPage', { errors: errors.array() });
   //if api caller return res.status(422).json({ errors: errors.array() });
  }
  else{
    //here everything is ok to proceed
   res.render('successPage', { data });
   //to api caller  res.json({msg : "ok"})
  }

})