Integration Testing

Integration Testing

Table of Contents

• Overview
• When to Use
• Quick Start
• Reference Guides
• Best Practices

Overview

Integration testing validates that different components, modules, or services work correctly together. Unlike unit tests that isolate single functions, integration tests verify the interactions between multiple parts of your system including databases, APIs, external services, and infrastructure.

When to Use

• Testing API endpoints with real database connections
• Verifying service-to-service communication
• Validating data flow across multiple layers
• Testing repository/DAO layer with actual databases
• Checking authentication and authorization flows
• Verifying message queue consumers and producers
• Testing third-party service integrations

Quick Start

Minimal working example:

// test/api/users.integration.test.js
const request = require("supertest");
const app = require("../../src/app");
const { setupTestDB, teardownTestDB } = require("../helpers/db");