Build an API With Fastify and MongoDB

Xpertlab – Android Application Development Company in Junagadh

Express.js is a battle-tested framework that is an absolute breeze to use. Even though Express is light, there is often a need for a backend system that is even faster. This allows your app to be snappier and more responsive.

This is where Fastify comes in. It is a framework that is more efficient and speedier than Express due to lower overhead. This means that your server will stay responsive even when dealing with heavy workloads. In fact, according to Sergey Onufrienko, Fastify is around 20% faster than Express.

Other than speed, what does it have to offer? For one, it has a growing library of plugins. Most importantly, it has a schema system. For example, assume that you have the following response from your server:

What if your front end only wants the name field? By using Fastify’s schema system, you can set a filter and send the name field as a response:

In this article, you will learn how to build an API using MongoDB and Fastify as your backend framework.

Xpertlab – Android Application Development Company in Junagadh

Getting Started

Project setup

To initialize a Node.js app, run the following terminal commands:

mkdir fastify-tutorial #create directory

cd fastify-tutorial

cd fastify-tutorial

touch index.js #our main file

npm init -y #initialize the project

Let’s now install the required dependencies. Here, we want the following packages:

• dotenv: To use environment variables.
• fastify: To build our backend.
• fastify-mongodb: Fastify’s plugin to help us interact with our database.
• mongodb: To allow us to parse URL parameters and convert them into ObjectID fields.

To get these modules, run the following command:

npm i dotenv fastify fastify-mongodb mongodb 

Next, go to your .env file and paste your MongoDB connection string like so:

CONNECT_DB = connectionString

Project directory

In your project’s folder structure, make the following folders:

• controllers: To hold our application logic.
• routes: This directory will hold our routes and their respective handlers.

In the end, your project’s folder structure should look like this:

Creating Our API

Home route

In /index.js, write the following code:

const fastify = require(“fastify”)({ logger: true });

const dotenv = require(“dotenv”);

dotenv.config();

fastify.register(require(“fastify-mongodb”), { forceClose: true, url: process.env.CONNECT_DB, }); fastify.get(“/”, function (req, reply) { reply.send(“Hello, world!”); }); fastify.listen(8080, function (err, address) { if (err) { fastify.log.error(err); process.exit(1); } fastify.log.info(`server listening on ${address}`); });

• Line 1: Bring in the fastify module. The logger property tells Fastify to log out the user’s routes and response codes to the terminal.
• Lines 6-9: Use the fastify-mongodb plugin so that we can use our database in our project.
• Lines 11-13: If the user goes to the / route, display a response.
• Line 15: Run our backend on port 8080.

Let’s test it out. Go to your API client and make a request to localhost:8080.

Great! Our code works.

Xpertlab – Android Application Development Company in Junagadh

Adding users to the database

In your controllers folder, create a file called users.controller.js. Here, write the following code:

const ObjectID = require(“mongodb”).ObjectID;async function listUsers(req, reply) {const users = this.mongo.db.collection(“users”);const result = await users.find({}).toArray();console.log(result);reply.send(result);}async function addUser(req, reply) {const users = this.mongo.db.collection(“users”);const { name, age } = req.body;const data = { name, age };const result = await users.insertOne(data);reply.code(201).send(result.ops[0]);module.exports = { listUsers, addUser };

• Line 4: Get the users collection from the database.
• Line 5: List out all the users in the database and put them in an array.
• Line 7: In the end, send the result to the client.
• Line 13: Store the name and age fields from the payload and store them in the data object.
• Lines 14 and 15: Finally, save this data into the database and send this item to the client.

We have now written our logic. As the second step, let’s now register it as a handler.

In routes , create a file called users.js. Here, write the following code:

const { listUsers, addUser } = require(“../controllers/users.controller”);async function routes(fastify, options) {fastify.get(“/users”, listUsers);fastify.post(“/users”, addUser);module.exports = routes;

• Line 4: If the user goes to the /users route, run the listUser function.
• Line 5: When the user sends data to the /users route (a POST request), invoke the addUser method.

We’re almost done! All that’s left is to register the /users route.

To achieve this, go to /index.js and write this line:

fastify.register(require(“./routes/users”));

To get all the documents in the users collection, use a GET request:

To get all the documents in the users collection, use a GET request:

This was really easy!

In the end, /index.js should look like this:

const fastify = require(“fastify”) ({ logger: true }); const dotenv = require(“dotenv”); dotenv.config(); fastify.register(require(“fastify-mongodb”), { forceClose: true, url:process.env.CONNECT_DB, }); fastify.register(require(“./routes/users”)); fastify.get(“/”, function (req, reply) { reply.send({ message: “Hello! Go to /users instead” }); }); fastify.listen(8080, function (err, address) { if (err) { fastify.log.error(err);process.exit(1); } fastify.log.info(`server listening on ${address}`); });

Reading users from the database

In controllers/users.controller.js, add the following code:

//further code above… async function getUser(req, reply) {const users = this.mongo.db.collection(“users”);const result = await users.findOne({ _id: new ObjectID(req.params.id) });if (result) {return reply.send(result);}reply.code(500).send({ message: “Not found” });}module.exports = { listUsers, addUser, getUser };

• Line 4: Find the user with the particular id field. The req.params the object contains the URL parameters. In this case, we only want the id parameter.
• Lines 5-7: If it exists, return the result.
• Line 8: Otherwise, inform the client that this user does not exist.

Conclusion

If you are aiming to build an API that favors responsiveness and speed, then Fastify will fulfill your needs. Moreover, its vast ecosystem of plugins allows you to develop complicated features without writing lots of code.