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Gene KlamerusFlag for United States of America

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Getting errors trying to run a sample node/express example I copied from YouTube.

I've been building out a sample node/express example that Mosh put up on YouTube.

The issue at the moment is errors in using joi to validate a post request.

At this point the code is very small so I'm including it here.  It's just one file.

const Joi = require('joi');
const express = require('express');
const app = express();


const courses = [
    {id: 1, name: 'course1'},
    {id: 2, name: 'course2'},
    {id: 3, name: 'course3'},

app.get('/', (req, res) => {
    res.send('Hello World!!!');

app.get('/api/courses', (req,res) => {
    // res.send([1, 2, 3]);

app.get('/api/courses/:id', (req, res) => {
    const course = courses.find(c => === parseInt(;
    if (!course)
        res.status(404).send('A course with the provided id was not found');
});'/api/courses', (req, res) => {

    const schema = {
        name:  Joi.string().min(3).required()

    const result = Joi.validate(req.body, schema);

    if (result.error) {

    const course = {
        id: courses.length + 1,

const port = process.env.PORT || 3000;
app.listen(port, () => console.log(`Listening on port ${port}...`));

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The problem shows up when the code hits the Joi.validate step.  This generate the following error statement:

TypeError: Joi.validate is not a function

I'm afraid I'm completely baffled.  I'm trying to use a post from postman with the raw body content of
   "name": "Goo"

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This should not generate any errors, but if the complaint is with the validate statement I think I've got an earlier syntax error or typo of some sort.

Avatar of Gene Klamerus
Gene Klamerus
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I should have added that I just downloaded joi today.  I have version 7.15.1
Avatar of Julian Hansen
Julian Hansen
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Very interesting.  I didn't know we had any better ways of documenting uploaded to EE.  Thanks for the tip.
Thanks for the direction.

I was just following what was done in the video (one from Mosh doing express/node.js, but it's from 2018 so I'm guessing that joi got a major rework and what he recorded no longer works.  I'll switch things around today and see how that goes.
Thanks a lot.  That got me in the right direction.  I made the couple of changes below and things are fine now.

    const schema = Joi.object({
        name:  Joi.string().min(3).required(),

    const result = schema.validate(req.body);

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You are welcome.