Testing
End-to-End Testing NestJS Apps with Supertest and TestingModule
End-to-end tests for NestJS apps test the full HTTP stack — routing, guards, pipes, middleware, serialization — without deploying to a server.
Node.js
Latest
Testing
Testing NestJS GraphQL Resolvers, Subscriptions, and Schema Validation
Testing GraphQL APIs in NestJS requires a different approach than REST.
Testing
Firebase Cloud Messaging Testing Guide: Unit Tests, Device Token Mocking, and Payload Validation
Push notifications power engagement loops in virtually every mobile app, yet FCM integration code is notoriously undertested.
Testing
Fastify JWT Auth Testing: Protected Routes, Token Refresh, and RBAC
Authentication bugs are some of the most costly bugs to ship. Testing fastify-jwt means verifying that protected routes reject unauthenticated requests, that expired tokens fail gracefully, that the refresh flow issues new tokens correctly, and that RBAC rules enforce role boundaries. This post covers all four, with test patterns
Testing
Fastify Plugin Testing: Lifecycle Hooks, Decorators, and inject()
Fastify's plugin system is one of its best features — and one of the trickier things to test properly. This post covers how to use inject() for in-process route testing, how to verify lifecycle hooks fire in the right order, and how to assert that decorators are registered
Node.js
BullMQ Job Testing in Node.js: Queues, Workers, and Flow Producers
BullMQ is the modern successor to Bull for Node.js background job processing.
Testing
Socket.io Testing: Unit Tests with Jest, Integration with Supertest
Socket.io is the de-facto standard for bidirectional real-time communication in Node.js applications.
Testing
Testing Alexa Skills: Unit Tests and End-to-End Automation
Alexa Skill testing requires a layered approach: unit tests for individual intent handlers, integration tests for full request/response cycles, and end-to-end simulation with Bespoken. This guide covers all three layers with concrete examples in Node.js and Python. Building a reliable Alexa Skill is only half the
Node.js
Testing Node.js CLI Tools with oclif and Jest
Building a CLI tool with oclif is pleasantly structured. Each subcommand is a class with a run() method. Flags and args are declared statically.
Testing
Testing Socket.io Applications: Server-Side and Client-Side
Socket.io wraps WebSocket with rooms, namespaces, auto-reconnect, and a binary protocol — all of which require specific testing approaches.
Contract Testing
Pact JS Tutorial: Contract Testing for JavaScript APIs
This tutorial walks through implementing Pact contract testing in a Node.js microservice architecture.
Integration Testing
Testcontainers for Node.js: Database Integration Tests Done Right
Node.js integration tests that mock PostgreSQL and Redis test your assumptions, not your code. testcontainers starts real database containers during your Jest run and tears them down after. Your tests talk to the actual services — no mocks, no drift, no surprises. Key Takeaways testcontainers/node works with Jest, Vitest,