NestJS is a popular framework for developing Node.js applications, known for its modularity and Dependency Injection (DI) features that have captured the attention of many developers. But does this framework cause long-term issues in development and maintenance? In this article, we explore whether NestJS is truly against development or if it can remain a powerful tool for complex projects.
NestJS and Its Capabilities
NestJS, with features like modularity, Dependency Injection (DI), and strong testability, has become one of the most popular frameworks among Node.js developers. Due to its organized structure, scalability, and ease of managing dependencies, it has become the top choice for many developers working on complex and scalable projects.
NestJS extensively uses Inversion of Control (IoC) and Dependency Injection (DI) patterns. IoC in NestJS shifts dependency management from the code to the framework, while DI helps reduce direct dependencies and enhances testability. This combination allows developers to create modular, flexible, and maintainable code, which is particularly crucial in complex projects.
Key Challenges in Developing with NestJS
1. High Coupling (Excessive Dependency Between Modules and Classes)
Coupling, or dependency between modules and classes, occurs when different parts of the system are tightly interconnected. In such cases, any change in one component may necessitate changes in other parts. This dependency can lead to increased complexity, reduced flexibility, and a higher likelihood of errors.
Solution: Use Dependency Injection (DI) and define interfaces for services to reduce coupling between components.
2. Poor Layering
Poor layering refers to the lack of proper separation between different layers of the system. If these layers are not correctly separated, numerous issues such as reduced maintainability and increased system complexity can arise.
Solution: Implement a layered architecture, separating business logic into services and data access into repositories.
3. Unplanned Complexity Growth
As a project grows, its complexity naturally increases. If this complexity grows without proper planning and architectural design, it can lead to significant problems.
Solution: Regularly review the architecture, use appropriate design patterns, and divide the project into independent modules.
Signs of Development Issues in NestJS
1. Widespread Changes for Small Modifications
Every change, even minor ones, requires modifications in multiple modules, services, or classes. This issue usually arises due to high coupling and poor layering.
Solution: Reduce coupling by using interfaces and ensuring proper layer separation.
2. Difficulty in Code Testability
Writing unit tests and integration tests is difficult and time-consuming, especially if dependencies are directly embedded in the code.
Solution: Use Mocks and Stubs in tests to simulate dependencies and reduce the complexity of testing.
3. Increased Development Time and Reduced Productivity
Over time, making changes and adding new features to the project becomes significantly slower and more complex.
Solution: Regularly review the architecture, establish and adhere to coding standards, and use appropriate design patterns.
Proposed Architecture for Different Business Types
1. Fintech Businesses
Proposed Structure:
- Core Layer: Contains essential and shared components like interfaces, DTOs, and security elements (e.g., JWT and OAuth).
- Domain Layer: Manages business logic and policies related to financial transactions.
- Application Layer: Manages services and events, utilizing CQRS to separate commands from queries.
- Infrastructure Layer: Manages communication with databases and external services.
2. E-commerce Businesses
Proposed Structure:
- Modular Monolith: Each module is designed to manage a specific part of the system (e.g., products, users, orders).
- Shared Module: Includes shared components like email services, caching, and configuration files.
- API Gateway Layer: Manages incoming requests and routes them to the appropriate modules.
3. Tourism and Travel Businesses
Proposed Structure:
- Core Module: Contains shared and essential components like configurations, security, and user management.
- Feature Modules: Each module is dedicated to a specific feature (e.g., hotel reservations, tickets, tours).
- Asynchronous Communication: Utilizes queues and asynchronous messaging to handle heavy loads and prevent interference.
4. B2B and Intermediary Platforms
Proposed Structure:
- Microservices Architecture with API Gateway: Each service manages a specific aspect like user management, payments, reporting, and interactions between companies.
- Shared Modules: Includes shared components like authentication, caching, and reporting.
- Message Queue: Manages asynchronous interactions and coordination between services.
5. Customer Support and After-Sales Service Businesses
Proposed Structure:
- Modular Monolith with Scalability: Includes modules for ticket management, multi-channel communication, and reporting.
NestJS: Friend or Foe of Development?
NestJS, with its powerful features and use of modern design patterns, is a strong tool for Node.js developers. However, it can introduce unnecessary complexity, especially in smaller projects.
Strengths:
- Modular Structure: Suitable for large and scalable projects.
- TypeScript Support: Allows developers to leverage static typing.
- Integration with Modern Tools and Technologies: Such as GraphQL and Microservices.
- Dependency Injection: Reduces coupling and enhances testability.
Weaknesses:
- Complexity in Simple Projects: Using NestJS may introduce unnecessary complexity.
- Learning Curve: For developers unfamiliar with TypeScript, learning NestJS can be time-consuming.
Conclusion
With its growing popularity among developers and active support from the open-source community, NestJS has become one of the leading frameworks for developing Node.js applications. By leveraging modern design principles and its high flexibility, NestJS can become a stable and suitable tool for large and long-term projects.
Recommendations for Developers:
1. Design the Architecture Correctly from the Start: Begin projects with a modular and extensible structure.
2. Effective Use of Dependency Injection (DI): Utilize DI to reduce direct dependencies between different parts of the code.
3. Separate Responsibilities: Use appropriate design patterns to ensure that changes in one part of the system have minimal impact on others.
4. Documentation and Adherence to Coding Standards: Always document your code and follow coding standards to ensure that other team members can easily understand and maintain it.
