How to create a server with Node, Fastify and MongoDB

#javascript #tutorial #node #beginners

Fastify is more and more popular and more performant than Express. I decide to learn Fastify to use it in a real project. All information about Fastify, you can find here

1) I create a directory fastifyBooks

mkdir fastifyBooks
cd fastifyBooks
npm init

2) When npm is initialized I can install fastify:

npm i fastify

3) It's time to create directory src in fastifyBooks and there I create my entry file app.js Here I will write my server.

mkdir src
cd src
touch app.js

4) Now I can use festify and I create a server in app.js

import Fastify from 'fastify'


const fastify = Fastify({
  logger: true
})


fastify.get('/', function (request, reply) {
    reply.send({ hello: 'world' })
  })


fastify.listen(3000, function (err) {
    if (err) {
      fastify.log.error(err)
      process.exit(1)
    }
    else{
        console.log("server is on port 3000")
    }
})

In this file, I use ES6 not CJ so I have this error when I want to start a server:

SyntaxError: Cannot use import statement outside a module

So I fix a bug, in package.json I put this line of code:

"type": "module",

And now my server works:

5) But I want also MongoDB in my little project so I install it:

npm install mongoose

6) In the directory fastifyBooks I create a directory config where I will put the file db.js

mkdir config
cd config
touch db.js

7) And I write a function to connect DB with server:

import mongoose from 'mongoose'
const db = "databaseàmoi";
const passwordDb="monpass"
const URI =`mongodb+srv://Deotyma:${passwordDb}@cluster0.uncn9.mongodb.net/${db}?retryWrites=true&w=majority`;


const MongoDBbooks = {
    initialize: () => {
        try {
            const client = mongoose.connect(URI, 
                { 
                    useNewUrlParser: true, 
                    useUnifiedTopology: true
                })


            client.then(() => {return console.log(`successfully connected to DB: ${db}`)})
            .catch((err)=> {console.log(err)})
        } catch(err) {
             throw Error(err)
        }
    }
}


export default MongoDBbooks;

7) Now I need to import it to app.js:

import MongoDBbooks from '../config/db.js';

the path is very important.

And now when I need to modify function witch run a server like that:

const start = async()=>{
    try{
        fastify.listen(3000);
        MongoDBbooks.initialize();
    }
    catch(error){
        fastify.log.error(err)
        process.exit(1)
    }
}
start();

At the same moment, I start a server and I initialise a connection with DB.

Now my application is ready for routes.