Architecture reference for Node.js applications

This document is a reference for the architecture of Node.js applications. It is based on the experience of the author and the best practices of the community.

Table of contents

1. Introduction
2. Project structure
3. Development
4. Conclusion
5. References

Introduction

Node.js is a runtime environment for executing JavaScript code server-side. It is built on top of the V8 JavaScript engine and uses an event-driven, non-blocking I/O model that makes it lightweight and efficient. Node.js' package ecosystem, npm, is the largest ecosystem of open source libraries in the world.

Node.js is commonly used to build web applications, RESTful APIs, real-time services, microservices, and more. It is widely adopted by companies like Netflix, Uber, PayPal, and LinkedIn.

This document provides guidelines and best practices for building Node.js applications.

Project structure

The project structure should be organized in a way that is easy to understand, easy to navigate, and easy to maintain. It should follow a modular architecture that separates concerns and promotes reusability.

A common project structure for a Node.js application is as follows:

project/
│
├── src/
│   ├── services/
│   ├── controllers/
│   ├── routes/
│   ├── middlewares/
│   ├── models/
│   ├── database/
│   ├── config/
│   ├── logger/
│   ├── errors/
├── tests/
|   |── ...
├── app.ts
│   └── ...
├── package.json
├── .gitignore
├── .env
└── ...

• The src/ directory contains the source code of the application. It is organized into subdirectories for services, controllers, routes, middlewares, models, database, configuration, logging, and errors.

• The services/ directory contains the business logic of the application. It is organized into modules that encapsulate related functionality.

• The controllers/ directory contains the request handlers of the application. It is organized into modules that handle HTTP requests and responses.

• The routes/ directory contains the route definitions of the application. It is organized into modules that map URLs to controllers.

• The middlewares/ directory contains the middleware functions of the application. It is organized into modules that process HTTP requests before they reach the controllers.

• The models/ directory contains the data models of the application. It is organized into modules that represent the structure of the data.

• The database/ directory contains the database configuration of the application. It is organized into modules that connect to the database and define schemas.

• The errors/ directory contains the error handling logic of the application. It is organized into modules that handle errors and return appropriate responses.

• The tests/ directory contains the test cases of the application. It is organized into subdirectories for unit tests, integration tests, and end-to-end tests.

• The app.ts file is the entry point of the application. It initializes the application, loads the configuration, connects to the database, and starts the server.

• The package.json file contains the metadata of the application. It defines the name, version, description, dependencies, scripts, and other settings.

• The .gitignore file contains the list of files and directories that should be ignored by Git. It prevents sensitive information and build artifacts from being committed to the repository.

• The .env file contains the environment variables of the application. It defines the database URL, API keys, and other settings that should not be hard-coded in the source code.

Development

The development process should follow best practices to ensure the quality, reliability, and maintainability of the application. It should include code reviews, testing, documentation, version control, and continuous integration.

Code reviews help identify bugs, improve code quality, and share knowledge among team members. They should be done regularly and involve multiple team members.

Testing helps ensure that the application works as expected, even after changes are made. It should include unit tests, integration tests, and end-to-end tests.

Documentation helps explain the purpose, design, and usage of the application. It should include a README file, inline comments, and API documentation.

Version control helps track changes, collaborate with team members, and revert to previous versions if needed. It should use a version control system like Git and follow a branching strategy like Gitflow.

Continuous integration helps automate the build, test, and deployment process. It should use a continuous integration server like Jenkins, Travis CI, or CircleCI.

Conclusion

Node.js is a powerful platform for building server-side applications. By following the guidelines and best practices outlined in this document, developers can build high-quality, scalable, and maintainable Node.js applications.

References

• Node.js
• npm
• Express
• MongoDB
• Jest