How to test POST Method of Express with Postman?

The POST method is a crucial aspect of web development, allowing clients to send data to the server for processing. In the context of Express, a popular web framework for Node, using the POST method involves setting up routes to handle incoming data. In this article, we’ll explore how to test the POST method of Express with Postman.

Prerequisites:

• Basic knowledge of Node and Express.
• npm(node package manager)
• Basics of Postman.

Steps to create Express Application and testing POST method.

Step 1: Create a folder for Express Application

mkdir express-postMethod
cd express-postMethod

Step 2: Initialized the express application and install the required dependencies and create respective files

npm init -y
npm i express body-parser nodemon
touch app.js

Project Structure:

Folder Structure

The updated dependencies in package.json file will look like:

"dependencies": {
    "body-parser": "^1.20.2",
    "express": "^4.18.2",
    "nodemon": "^3.0.2"
}

Example: Let’s create a simple Express route that handles a POST request.

JavaScript

//app.js

const express = require('express');
const bodyParser = require('body-parser');

const app = express();
const port = 3000;

// Middleware to parse JSON data
app.use(bodyParser.json());

// POST route to handle incoming data
app.post('/api/data', (req, res) => {
    const requestData = req.body;
    // Process the received data (e.g., save to a database)
    console.log('Received data:', requestData);
    // below picture is given of console data on server
    res.status(200).send('Data received successfully!');
});

// Start the server
app.listen(port, () => {
    console.log(`Server is listening on port ${port}`);
});

Step 3: Run the express application by running the following command.

nodemon app.js

Step 4: Open the Postman application to test the POST method. In the collection add a new POST request.

Step 5: In the URL section add the API URL and in body section add the data you want to send and click on send button.

URL:

http://localhost:3000/api/data

Body json data:

{
    "name": "John Doe",
    "age": 30,
    "city": "Example City"
}

Output:

1. Terminal Output:

Terminal Output

2. Postman output:

Postman output