We Keep Coding

Issue while trying to call an existing route from within another route in Express JS project

In an Express JS connected to a mySQL db, I am trying to get some data of an already defined route/ query:
// customers.model.js
CUSTOMERS.getAll = (result) => {
let query = "SELECT * FROM customers"
sql.query(query, (err, res) => {
if (err) {
console.log("error: ", err)
result(null, err)
return
}
result(null, res)
})
}
// customers.controller.js
// GET customers is a standalone route and should output all the customers when called.
const CUSTOMERS = require("../models/customers.model.js")
exports.findAll = (req, res) => {
return CUSTOMERS.getAll((err, data) => {
if (err)
res.status(500).send({
message: err.message ||
"Some error occurred while retrieving customers...",
})
else res.send(data)
})
}
In payments.controller.js I would firstly like to get all users so I can do something with the data:
// payments.controller.js
// GET payments is also a standalone route and should get the customers,
// do something with the data and output a calculation with the help of this data
const CUSTOMERS = require("../models/customers.model.js")
exports.calculateAll = (req, res) => {
const customers = CUSTOMERS.getAll((err, data) => {
console.log('this always has correct data', data)
if (err) return err
else return data
})
console.log('this is always undefined', customers)
...
res.send(whatEverCalculatedData)...
}
But that data here is always undefined.
What am I doing wrong in the above, and what's the correct way to call this route inside another route?
I know it has similarities with this question but I couldn't sort it out for my particular example.

It's due to your call which is asynchronous.
You must wait your data being ready before rendering the results.
Maybe you could to use Promises or async/await statements.
For example:
CUSTOMERS.getAll = async () => {
const query = "SELECT * FROM customers";
try {
return await sql.query(query);
} catch (e) {
console.log(`An error occurred while fetching customers: ${e.message}.`);
return null;
}
}
exports.calculateAll = async (req, res) => {
try {
const data = await CUSTOMERS.getAll();
res.send(whatEverCalculatedData);
} catch (e) {
res.send(`Something went wront: ${e.message}.`);
}
}

countDocuments() is not working in api call

I am trying to get a count of products using api calls but in postman its keep loading
router.get(`/get/count`, async (req, res) => {
const productCount = await Product.countDocuments((count)=>count)
if (!productCount) {
res.status(500).json({ success: false });
}
res.send({
productCount: productCount
});
});
(node:28030) UnhandledPromiseRejectionWarning: MongooseError: Query was already executed: Product.countDocuments({})
without async and await also its not working
I try to catch the error and i got this error in postman
{
"success": false,
"error": "Query was already executed: Product.countDocuments({})"
}
code to catch error:
router.get(`/get/count`, (req, res) => {
Product.countDocuments((count)=>count).then((pcount)=>{
if(pcount){
return res.status(200).json({success:true})
}else{
return res.status(404).json({success:false})
}
}).catch((err)=>{
return res.status(400).json({success:false, error:err.message})
})
});

I think in Mongoose operations you want to either await or provide a callback, but not both. Attempting to do both causes it to internally execute the query twice.
Try just:
const productCount = await Product.countDocuments();

If you want to count all the products in your product collection, try this
db.product.countDocuments({})

router.get(`/get/count`, async(req, res) => {
let productCount = await Product.countDocuments();
if(!productCount){
res.send(500).json({success:false})
}
res.send({productCount: productCount})
});

Two way you can do that
Try it you don't need use callback (count)=>count
const express = require('express')
const router = express.Router();
const {Product} = require('../models/products')
const {Category} = require('../models/category')
const catchAsyncErrors = require('../middleware/catchAsyncError')
const mongoose = require('mongoose');
// Get all product
router.get(`/`, async (req, res) => {
let productList = await Product.find().populate('category')
if(!productList) {
res.status(500).json({
success: false
})
}
res.status(200).json({
success: true,
count: productList.length,
productList
});
})
router.get(`/count`, catchAsyncErrors(async(req, res) => {
const countProductList = await Product.countDocuments();
if(!countProductList){
res.status(500).json({
success: false
})
}
res.send({
success: true,
countProduct: countProductList
})
}))

You don't need to include ((count)=>count).
Use Product.countDocuments() instead

boolean from function is returning undefined node.js

I have 2 functions... 1st one in auth.js, which does this:
const adminCheck = (req, res) => {
console.log(“one”)
UtilRole.roleCheck(req, res, ‘ADMIN’, (response) => {
if(response) {
return true
} else {
return false
}
})
}
module.exports = {
adminCheck
}
basically checks if the user is an admin in my table. that works, but I am trying to retrieve the boolean in my function in my index.js function, which is below.
router.get(‘/viewRegistration’, auth.ensureAuthenticated, function(req, res, next) {
console.log("authcheck: " + auth.adminCheck())
const user = JSON.parse(req.session.passport.user)
var query = “SELECT * FROM tkwdottawa WHERE email = ‘” + user.emailAddress + “’”;
ibmdb.open(DBCredentials.getDBCredentials(), function (err, conn) {
if (err) return res.send(‘sorry, were unable to establish a connection to the database. Please try again later.’);
conn.query(query, function (err, rows) {
if (err) {
Response.writeHead(404);
}
res.render(‘viewRegistration’,{page_title:“viewRegistration”,data:rows, user});
return conn.close(function () {
console.log(‘closed /viewRegistration’);
});
});
});
})
where I am logging the value in the console.log right under where I initialize the function, it is returning undefined. how can I fix this?

You need to use Promise and wrap all callbacks to actually return a given result value from a function that uses a callback because usually a callback is called asynchronously and simply returning a value from it does not help to catch it in a calling function.
const adminCheck = (req, res) => {
console.log(“one”)
return new Promise(resolve, reject) => {
UtilRole.roleCheck(req, res, ‘ADMIN’, (response) => {
if(response) {
resolve(true)
} else {
resolve(false)
}
})
}
});
then you need to await a result calling this function using await keyword and marking a calling function as async:
router.get(‘/viewRegistration’, auth.ensureAuthenticated, async function(req, res, next) {
console.log("authcheck: " + await auth.adminCheck())
const user = JSON.parse(req.session.passport.user)
var query = “SELECT * FROM tkwdottawa WHERE email = ‘” + user.emailAddress + “’”;
ibmdb.open(DBCredentials.getDBCredentials(), function (err, conn) {
if (err) return res.send(‘sorry, were unable to establish a connection to the database. Please try again later.’);
conn.query(query, function (err, rows) {
if (err) {
Response.writeHead(404);
}
res.render(‘viewRegistration’,{page_title:“viewRegistration”,data:rows, user});
return conn.close(function () {
console.log(‘closed /viewRegistration’);
});
});
});
})

That's simple. You just forgot to return the inner function's return value
const adminCheck = (req, res) => {
console.log(“one”)
return UtilRole.roleCheck(req, res, ‘ADMIN’, (response) => {
if(response) {
return true
} else {
return false
}
})
}
module.exports = {
adminCheck
}

Sinon test failing after change made to function

I have this test:
describe('createNote', () => {
beforeEach(() => {
res = {
json: sinon.spy(),
sendStatus: sinon.spy(),
};
});
afterEach(() => {
noteService.createUserNote.restore();
});
it('should return user note object', async () => {
// Arrange
modelResponse = {
id: 1,
userId: req.user.id,
...req.body,
};
sinon.stub(noteService, 'createUserNote')
.resolves(modelResponse);
// Act
await userController.createNote(req, res);
// Assert
sinon.assert.calledWith(
noteService.createUserNote,
req.user,
req.body.note,
);
sinon.assert.calledWith(res.json, { note: modelResponse });
});
It fails on line sinon.assert.calledWith(res.json, { note: modelResponse });
I don't really understand sinon so I'm not sure why though.
This is my userController code:
createNote: async (req, res, next) => {
try {
const createNote = await noteService.createUserNote(
req.user,
req.body.note,
);
const note = await noteService.getUserNote(
req.user.id,
createNote.id,
);
return res.json({ note });
} catch (err) {
return next(err);
}
},
I recently changed it from this so assume something in what I've done has caused the test to fail:
createNote: async (req, res, next) => {
try {
const note = await noteService.createUserNote(
req.user,
req.body.note,
);
return res.json({ note });
} catch (err) {
return next(err);
}
},
This is the error I get:
1) User userController
createNote
should return user note object:
AssertError: async (user, text) => {
const [note] = await db.Note.createUserNote(user.id, text, db);
await emailService.userAlert(text, user.name);
return note;
} is not stubbed
at Object.fail (node_modules/sinon/lib/sinon/assert.js:106:21)
at /opt/atlassian/pipelines/agent/build/node_modules/sinon/lib/sinon/assert.js:35:24
at Array.forEach (<anonymous>)
at verifyIsStub (node_modules/sinon/lib/sinon/assert.js:22:5)
at Object.assert.(anonymous function) [as calledWith] (node_modules/sinon/lib/sinon/assert.js:77:9)
at Context.it (app/__tests__/controllers/user/userController.test.js:56:20)
at <anonymous>
Can anybody explain what is wrong and how to fix this?

You need to mock getUserNote as well. After the change, you are getting note from getUserNote and then sending it to res.json
But in the test case you have not stubbed it. Try adding this in the test case:
sinon.stub(noteService, 'getUserNote')
.resolves(modelResponse);

High order function in express middleware

Can't send params to a high order function in JS. The function it's not getting req and res args
// In router.js
const { getAll } = require('./controller')
router.get('/coordinadores', getAll()('mentor'))
// In controller.js
exports.getAll = (req, res) => {
return (role) => {
var filter = { role }
if (req.user.role == 'mentor') filter = { role, centro: { "$in": req.user.centro } }
Model.find(filter, '-password -role -__v -createdAt -updatedAt -centro').lean().exec()
.then(list => { res.status(200).json({ list }) })
.catch(err => { errorHandler(req, res, err) })
}
}
// Result
// TypeError: Cannot read property 'user' of undefined

Here
router.get('/coordinadores', getAll()('mentor'))
you're calling getAll without any arguments. To create a HoF you should create it like this
const getAll = role => (req, res) => {
// your code
}
and then
router.get('/coordinadores', getAll('mentor'))
this will call the getAll function with mentor and it will return a function reference that will be called with req and res by express

For an alternate, express way is to pass values through middleware like:
function setDefaultRole((req, res, next) => {
if (not some check here) {
// if check fails, setting default role
req.user.role = 'mentor'
}
// call the next middleware
next();
})
function getAll((req, res, next) => {
if (req.user.role == 'mentor') {
// continue logic
filter = ???
}
})