10 NestJS Folder Structure Best Practices
A well-organized project is essential for any software development team. In this article, we'll share 10 best practices for organizing your NestJS project.
NestJS is a popular Node.js framework for building efficient, reliable, and scalable server-side applications. It is based on TypeScript and uses Express.js as a web application framework.
When building a NestJS application, it is important to structure the code in a way that is easy to maintain and understand. This article will discuss 10 best practices for structuring your NestJS project folders. By following these best practices, you can ensure that your application is organized and easy to navigate.
1. Create a folder for each feature
When you create a folder for each feature, it helps keep your code organized and easier to maintain. It also makes it easier to find the files related to a particular feature when you need to make changes or debug an issue. Additionally, having separate folders for each feature allows you to easily add new features without disrupting existing ones.
Creating a folder for each feature is especially important if you’re working on a large project with multiple developers. This way, everyone can work on their own feature without worrying about conflicting with someone else’s code.
2. Use the same name for your feature and its folder
When you use the same name for your feature and its folder, it makes it easier to find related files. For example, if you have a feature called “Users” then all of the related files will be in the “users” folder. This helps keep your code organized and easy to navigate.
It also makes it easier to understand what each file is used for. If you have a file named “user-controller.js”, it’s immediately clear that this file contains the controller logic for the Users feature. This can help reduce confusion when working with large projects.
3. Put all files related to a feature in the same folder
When you have all the files related to a feature in one folder, it makes it easier for developers to find what they need. It also helps keep your codebase organized and easy to navigate. This is especially important when working on larger projects with multiple features.
Having a consistent folder structure also makes it easier to maintain and update your code. When you know where everything is located, it’s much simpler to make changes or add new features. Finally, having a well-structured folder structure can help reduce errors and bugs by making sure that all of the necessary files are included.
4. Organize folders by layers
By organizing your folders by layers, you can easily identify which files are related to a specific feature or module. This makes it easier for developers to find the code they need and reduces the time spent searching through multiple folders.
For example, if you have an authentication module, you could create a folder called “auth” that contains all of the necessary files such as controllers, services, guards, etc. This way, when someone needs to make changes to the authentication module, they know exactly where to look.
Organizing folders by layers also helps keep your project organized and maintainable in the long run. It’s much easier to add new features or refactor existing ones when everything is neatly organized into separate folders.
5. Keep your code organized with modules
Modules are a way to group related components, services, and controllers into one unit. This makes it easier for developers to find the code they need quickly and easily. It also helps keep your application more organized and maintainable in the long run.
Modules should be named according to their purpose, such as “users” or “products”. Each module should have its own folder with all of the relevant files inside. For example, if you have a users module, then there should be a folder called “users” that contains all of the necessary files for that module. This will help keep your codebase clean and easy to navigate.
6. Don’t put too much logic into controllers
Controllers are responsible for handling incoming requests and returning responses. They should not contain any business logic or data manipulation, as this can lead to code that is difficult to maintain and debug.
Instead, controllers should be used to call services which handle the actual business logic. This allows you to keep your controller code clean and organized, while also making it easier to test and debug. It also makes it easier to add new features in the future since all of the business logic will already be contained within the service layer.
7. NestJS uses Pipes to transform data
Pipes are a great way to keep your code clean and organized. They allow you to separate the logic of transforming data from the rest of your application, making it easier to maintain and debug.
Pipes also make it easy to reuse code across different parts of your application. For example, if you have a pipe that transforms an object into a JSON string, you can use that same pipe in multiple places without having to write the same code over again. This makes development faster and more efficient.
Finally, Pipes provide a layer of abstraction between your application and the underlying data source. This helps ensure that changes to the data source don’t break your application, as long as the Pipe is updated accordingly.
8. Services are used to encapsulate business logic
Services are used to provide a single source of truth for the application. This means that all business logic is contained in one place, making it easier to maintain and debug.
Services also help keep code organized by separating out different types of functionality into separate files. For example, you can have a service file for authentication, another for data access, and yet another for business logic. This makes it much easier to find what you’re looking for when debugging or adding new features.
Finally, services make it easy to share common functionality across multiple modules. By creating a service that contains shared logic, you can easily reuse this code in other parts of your application without having to duplicate it.
9. Interfaces define contracts
Interfaces are a great way to define the shape of an object, and they can be used to ensure that objects conform to certain standards. This is especially useful when working with third-party APIs or libraries, as it allows you to easily check if the data returned from them matches what your application expects.
Interfaces also make it easier to refactor code, since any changes made to the interface will automatically propagate throughout the entire application. Finally, interfaces provide a layer of abstraction which makes it easier for developers to understand how different parts of the application interact with each other.
10. DTOs (Data Transfer Objects) transfer data between layers
DTOs are objects that contain data which is sent between layers. They help to ensure that the data being transferred is valid and consistent, as well as providing a layer of abstraction from the underlying implementation details. This helps to keep your codebase clean and maintainable.
When creating a NestJS folder structure, it’s important to create a dedicated folder for DTOs. This will make it easier to find them when needed, and also makes it clear what their purpose is. It’s also a good idea to name the folder something like “dtos” or “data-transfer-objects”.