Examples
TS Node.js API
Building a TypeScript Node.js API
TypeScript Node.js API uses Express with typed routes and middleware.
Introduction to TypeScript with Express
Using TypeScript with Node.js and Express allows developers to write type-safe APIs. TypeScript brings static typing to JavaScript which helps in catching errors early during development. In this tutorial, we'll explore how to set up a Node.js API project using TypeScript, Express, and how to implement typed routes and middleware.
Setting Up the Project
Start by creating a new directory for your API project and initializing a Node.js project.
Navigate into your project directory and run the following commands to set up the initial structure:
Next, set up your TypeScript configuration. Create a tsconfig.json file in the root of your project:
Creating the Express Server
Now, let's create our Express server. Create a src directory and add an index.ts file:
Adding Type-Safe Routes
To make routes type-safe, define interfaces for request and response objects. For instance, let's create a route to fetch user data:
Create a types.d.ts file in the src directory:
Use this interface in a new route in index.ts:
Implementing Middleware
Middleware functions are an essential part of Express. They allow you to execute code, modify the request and response objects, end the request-response cycle, and call the next middleware function in the stack. Here's how you can create a simple logger middleware:
Running Your TypeScript Node.js API
To run your TypeScript API, use ts-node which allows you to directly execute TypeScript files. Run the following command:
Your server should now be running and accessible at http://localhost:3000. You should see the message from your root route and a JSON response from your user route.
