Error: Reference.set failed: First argument contains undefined in property - node.js

Question

I'm trying to test a POST method in a Nodejs/express application. I've connected to the firebase database.
My question is mainly related to the error. What am I doing wrong and how can I fix this please?
This is the error report:
PS C:\Users\WorkoutApp_v1> node app.js
Server started on port: 3000
Error: Reference.set failed: First argument contains undefined in property 'workouts.-Lqkqtcf6e2RED2F_1av.name'
This is the workout.js file with POST method.
const express = require('express');
const router = express.Router();
const firebase = require('firebase');
router.get('/add', function(req,res,next) {
res.render('workouts/add');
});
router.post('/add', function(req,res,next) {
var workout = {
name: req.body.name,
discription: req.body.discription,
set: req.body.set,
repsTime: req.body.repsTime
}
// console.log(workout);
// return;
// const fbRef = firebase.database().ref();
// var dbRef = fbRef.child('workouts');
// dbRef.push().set(workout);
// alternative implementation of the above 3-lines
firebase.database().ref().child('workouts').push().set(workout);
req.flash('success_msg', 'Workout saved');
res.redirect('/workouts');
});
module.exports = router;
This is the add.ejs file.
<form method="post" action="/workouts/add">
<div class="form-group">
<label>Exercise</label>
<input type="text" class="form-control" name="name" placeholder="Workout Name">
<label>Description</label>
<input type="text" class="form-control" name="description" placeholder="Description">
<label>Set</label>
<input type="text" class="form-control" name="sets" placeholder="Number of sets">
<label>RepsTime</label>
<input type="text" class="form-control" name="repsTime" placeholder="Number of repsTime">
</div>
<button type="submit" class="btn btn-default">Submit</button>
<a class="btn btn-danger" href="/workouts">Close</a>
</form>

Answer 1

The value undefined can't be written in RTDB.
The value undefined is what you get when you access object properties that don't exist.
Your req.body.name is undefined because req.body doesn't have a name property.
What does your commented-out console.log(workout) print?
When you write code that might lead to writing undefined in RTDB, you should replace it with something else. In this scenario, you could use req.body.name || '', to replace a missing name property with an empty string.
In general, using || can cause trouble, because values like 0 and '' are equivalent to false, so they would be replaced by your default value.
A safer thing to do is value === undefined ? defaultValue : value.