CODEWITHSUNDEEP
node.jsexpressmodule
berimbolo
berimbolo

Reputation: 3859

Node\Express - "TypeError: require(...) is not a function" or app is undefined

I keep getting this error message after refactoring my code into separate js files. I have tried numerous different methods based on SO posts but nothing seems to work, I either get this error or the app variable is undefined in my controller.

I am a complete Node novice so if someone can point me in the right direction I would be very grateful!

Node version: v6.17.0

app.js

const express = require('express');
const app = express();
const controller = require('./plate-controller');

module.exports.app = app;

controller

const plateService = require('./plate-service');

var app = require('./app').app;
var exports = module.exports = {};

exports.controller = function(app) {
    app.get('/plates/:plate_id', function (req, res) {
        return plateService.getPlateById(req, res);
    });

    app.get('/plates/search/:plate', function (req, res) {
        return plateService.search(req, res);
    });

    app.get('/plates/current-plates', function (req, res) {
        return plateService.getCurrentPlates(req, res);
    });

    app.get('plates/prefix-plates', function (req, res) {
        return plateService.getPrefixPlates(req, res);
    });
};

This gives undefined and trying to call like require('..')() always give the is not a function error.

When printing out the controller variable to the console it actually doesnt look as I thought it would, a function, rather its a function inside an object so I suppose that is the cause of the require(...) is not a function.

{ controller: [Function] }

Upvotes: 0

Views: 254

Answers (2)

berimbolo
berimbolo

Reputation: 3859

I think I have worked this out now so in case this saves someone else some pain then here is the way I did it, I had followed a tutorial to get this far and I didnt realise that the function would be wrapped in an object when it was returned.

If there is a better way to do this then please let me know.

const controllerExports = require('./plate-controller');
controllerExports.controller(app);

Upvotes: 0

PaulShovan
PaulShovan

Reputation: 2134

When require is called, module.exports is returned. export is not returned.

instead of using exports.controller use module.exports.controller like this:

module.exports.controller = function(app) {
app.get('/plates/:plate_id', function (req, res) {
    return plateService.getPlateById(req, res);
});

app.get('/plates/search/:plate', function (req, res) {
    return plateService.search(req, res);
});

app.get('/plates/current-plates', function (req, res) {
    return plateService.getCurrentPlates(req, res);
});

app.get('plates/prefix-plates', function (req, res) {
    return plateService.getPrefixPlates(req, res);
});
};

For more information, you can look at this answer

Upvotes: 1

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