Fastify is a web framework for Node.js focused on providing the best developer experience with the least overhead and a powerful plugin architecture. It is one of the fastest web frameworks available for Node.js.
Fastify Anti-Patterns Overview
Fastify, despite its performance and plugin-based architecture, has several common anti-patterns that can lead to performance issues, maintenance problems, and security vulnerabilities. Here are the most important anti-patterns to avoid when developing with Fastify.
Not Using the Schema Validation
Manual validation is error-prone and verbose. Use Fastify’s built-in schema validation based on JSON Schema to automatically validate requests and generate documentation.
Not Using Proper Error Handling
Inconsistent error handling leads to poor user experience and security issues. Use custom error classes and Fastify’s error handler to centralize error handling logic.
Not Using Async/Await Properly
Mixing callbacks with async/await makes code harder to read and reason about. Be consistent with async/await throughout your route handlers.
Not Using Plugins Properly
Registering all plugins globally can lead to unnecessary overhead and potential security issues. Use Fastify’s encapsulation to scope plugins only to the routes that need them.
Not Using Hooks Properly
Duplicating cross-cutting concerns in each route handler leads to code duplication and maintenance issues. Use Fastify’s hooks to centralize common logic like authentication, logging, and error handling.
Not Using Serialization
Manual response transformation is error-prone and can lead to inconsistent APIs. Use Fastify’s response schemas to automatically serialize responses and filter out sensitive fields.
Not Using the Reply Interface Properly
Mixing response patterns makes code harder to read and maintain. Choose one consistent pattern for handling responses throughout your application.
Not Using Content Type Parsing Properly
Not configuring appropriate content type parsers leads to errors when handling different types of requests. Register the appropriate parsers for your API’s needs.
Not Using Decorators Properly
Using global variables makes testing difficult and can lead to unexpected behavior. Use Fastify’s decorators to attach shared resources to the server, request, or reply objects.
Not Using Proper Logging
Using console.log
doesn’t provide structured logging or log levels. Use Fastify’s built-in logger for structured, configurable logging.
Not Using Environment Configuration
Hardcoded configuration makes deployment difficult and poses security risks. Use environment variables for configuration and provide sensible defaults.
Not Using TypeScript
Not using TypeScript can lead to runtime errors and makes refactoring more difficult. Use TypeScript to catch errors at compile time and improve code maintainability.