CODEWITHSUNDEEP
node.jsexpresscallbacknode-asyncnode-request
JasonA
JasonA

Reputation: 281

Node Error: Route.get() requires callback functions but got a [object Undefined]

I have not found a question with a similar setup... how do I fix this?

I'm using node, express routing, request to call a token from an api, and async series to keep everything clean. I simplified the code by only showing one function in the async series.

routes.js

var express = require('express')
var router = express.Router()
var isAuthenticated = require("./passportAuth.js")
var tokens = require('./tokens')

module.exports = function() {
  router.get('/allTokens', isAuthenticated, tokens())
  return router
}

./tokens.js

var request = require("request")
var async = require('async')

module.exports = function(req, res, next) {

  var allTokens = function(callback) {
    request('url', function(err, res, body) {
      if(err) return callback(err, null)
      return callback(null, 'success')
    })
  }

  var asyncFinally = function(err, results) {
    if(err) return next(err)
    res.send(results)
  }

  async.series([allTokens], asyncFinally)
}

Error message

Route.get() requires callback functions but got a [object Undefined]

Upvotes: 1

Views: 1852

Answers (2)

jfriend00
jfriend00

Reputation: 707916

You are prematurely calling the tokens() function rather than just passing a reference to it. Change this:

router.get('/allTokens', isAuthenticated, tokens())

to this:

router.get('/allTokens', isAuthenticated, tokens)

Remember that any time you put () after a function name that means to call it now (immediately). Any time you just pass the function name by itself, that just passes a reference to the function that can be called later at the appropriate time (that's what you want here). This is a very common mistake.

Since calling tokens() returns undefined, that is what you end up passing to router.get() and thus why you get the specific error message you see.

Upvotes: 1

aeb0
aeb0

Reputation: 816

The router is expecting a function value but you are passing in an invoked function tokens(). Try just tokens.

Upvotes: 2

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