Mockery is a simple yet flexible PHP mock object framework for use in unit testing with PHPUnit, PHPSpec or any other testing framework. Its core goal is to offer a test double framework with a succinct API capable of clearly defining all possible object operations and interactions using a human readable Domain Specific Language (DSL).

An Xcode extension (plugin) to generate Swift test doubles automatically.

PHP Mocking Framework

🥃 Take your Ruby, and make it a double!

A Go mocking framework.

Service Virtualized HTTP - to help service test automation stay fast and consistent

A Swift test double library. Guava - looks like an apple but it's not.

Servirtium Overview

A python test double library

Reusable standard mocks and fakes for popular browser and Node.js APIs, framework/library objects for Jest

Imposter Mock Engine v5, written in Go. Runs in Docker, AWS Lambda, Kubernetes, local and more.

Auto-generate fully-typed test spies from a class — across Vitest, Bun & node:test, with Angular/NestJS/React/Vue/Svelte recipes. A jest-auto-spies drop-in replacement.

A Python version of Servirtium

Test Double library for Cincom Visualworks Smalltalk.

Simple test doubles over the wire

This guide clarifies the differences between dummies, stubs, fakes, spies, and mocks. It includes practical examples and attempts to clarify the optimal use cases for each type.

A deterministic, OpenAPI-driven mock server that generates realistic API responses with zero manual config.

Companion project to https://youtu.be/xSa2S-W7x48

Lightweight utilities to mock static methods and built-in functions in PHP unit tests