nodejs-best-practices

Separate Express routes from business logic by delegating HTTP handler requests to dedicated service layers. This separation of concerns keeps routes clean and moves complex logic into maintainable, testable service modules.

Handle database transactions in Node.js by using connection pooling and wrapping multi-step operations in a single transaction with proper rollback. This ensures data reliability when modifying multiple tables simultaneously.

Write Jest tests for Node.js services by setting up mock configurations for database query layers. Testing patterns focus on isolating service logic through mocks to ensure maintainable and comprehensive coverage.

Parameterized queries in Node.js prevent unsafe database interactions by separating SQL code from user input data. This secure configuration practice protects against injection attacks while maintaining reliable query execution.

You can refactor existing Express applications by progressively moving business logic into services, converting database calls to parameterized queries, and wrapping multi-table modifications in transactions with rollback support.

Maintain clean async/await usage in Node.js backends by applying consistent error handling and proper separation of concerns across Express routes, service layers, and database access points to prevent tangled logic.