Welcome to the exciting world of Clean Architecture! In this guide, we’ll explore how to build a clean and efficient API using node.js and TypeScript while adhering to the principles of clean architecture. But before we dive in, let’s remember that the API we’re going to develop is still under construction, and frequent changes are likely. Feel free to contribute and make it even better!

Understanding the Basics of Clean Architecture

Clean Architecture emphasizes a separation of concerns, allowing your application to remain scalable and maintainable. Think of it like a well-organized closet: each layer has its own section, making it easy to find what you need without rummaging through a mess. Here’s a breakdown of the layers involved:

• Domain Layer: The core of your application, containing business rules and entities that remain unchanged no matter what.
• Application Layer: This layer handles the application’s use cases and orchestrates data flow, connecting the entities to the outer layers.
• Presentation Layer: This is where the user interface resides, converting data to and from formats that the application and external systems can understand.
• Infrastructure Layer: The layer dealing with external frameworks, databases, and more, keeping them from muddying your core business logic.
• Main Layer: The layer where everything comes together, often mixed with factory functions to instantiate components across other layers.

Setting Up Your Project

To start building your API, follow these steps:

• Install Required Packages: Make sure you have node.js and TypeScript installed. Use the following command to set up your project:

npm install express knex typescript ts-node @types/node @types/express

• Establish Your Directory Structure: Organize your files to represent the layers discussed earlier. The following structure can serve as a starting point:

src
├── application
│   ├── controllers
│   ├── middlewares
│   ├── repositories
│   └── use-cases
├── domain
│   └── models
├── infrastructure
│   └── express
└── main

Implementing the User Model

With the base structure in place, you can create CRUD operations for users along with a sign-in system using tokens and refresh tokens. Switch into the application layer and define your User model. Consider this like creating a template for a variety of ice cream flavors—you want flexibility but with a defined base!

class User {
  id: number;
  username: string;
  password: string; 
  roles: string[];

  constructor(id: number, username: string, password: string, roles: string[]) {
    this.id = id;
    this.username = username;
    this.password = password;
    this.roles = roles;
  }
}

Creating API Routes

Let’s set up routes for the user model. These routes act as the entry points into your application, like doors that lead to different rooms in a house. Here’s how the routes could be structured:

const express = require('express');
const router = express.Router();

router.get('/users', getAllUsers);
router.get('/users/:id', getUser);
router.post('/users', createUser);
router.put('/users/:id', updateUser);
router.delete('/users/:id', deleteUser);

Troubleshooting Tips

As you develop your API, you may run into issues. Here are some common troubleshooting suggestions:

• Make sure all your dependencies are properly installed. Use npm install to ensure everything is set up.
• Check your routes to ensure there are no typos, as they can lead to “route not found” errors.
• If you experience authentication issues, verify your token logic and ensure that tokens are being generated correctly.
• Examine the logs for any unhandled errors or issues in your middleware that could be crashing your app.
• For more insights, updates, or to collaborate on AI development projects, stay connected with fxis.ai.

Wrap-Up

By understanding and implementing Clean Architecture in your API, you set the foundation for a robust, maintainable codebase that can grow and adapt over time. As you move forward, keep enhancing your project with new features and improvements. At fxis.ai, we believe that such advancements are crucial for the future of AI, as they enable more comprehensive and effective solutions. Our team is continually exploring new methodologies to push the envelope in artificial intelligence, ensuring that our clients benefit from the latest technological innovations.