Testing & Mocking Packages
Testing frameworks, assertion libraries, and mocking tools for writing reliable unit, integration, and end-to-end tests (testify, pytest, Vitest).
Packages in Testing & Mocking
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fakeredis
A pure-Python, in-memory implementation of the Redis protocol for testing.
pytest-order
Pytest plugin for running tests in a specific, controllable order
Opik
Python SDK for tracing, evaluating, and monitoring LLM applications, RAG pipelines, and agentic workflows.
GoConvey
Behavior-driven testing for Go with nested specs, rich assertions, and a live browser results UI.
chrome-remote-interface
A Node.js client for the Chrome DevTools Protocol, exposing every browser command, event, and type as a plain JavaScript API.
Behat
A behavior-driven development (BDD) testing framework for PHP driven by Gherkin.
behave
A Python behavior-driven development framework that runs Gherkin feature files against step definitions written in plain Python.
DoctrineFixturesBundle
Symfony integration for Doctrine Data Fixtures to load sample and test data into your database
testcontainers-python
Throwaway Docker containers for real integration tests, driven straight from Python.
randexp.js
Generates random strings that match any given JavaScript regular expression.
enigo
Cross-platform keyboard and mouse input simulation for Rust on Linux, macOS, and Windows.
fake-gcs-server
A Go emulator and library for Google Cloud Storage that runs your GCS-dependent tests without touching the real API.
chrome-launcher
Finds and launches Google Chrome from Node.js with the DevTools Protocol port open, ready for automation.
gofakes3
An embeddable fake AWS S3 server for local development and integration testing of S3-backed Go code.
arbitrary
The Rust trait for generating structured data from arbitrary, unstructured input
faker
Struct-tag-driven fake data generator for Go, turning any struct into realistic test fixtures with one function call.
pytest-html
A pytest plugin that turns your test run into an interactive, shareable HTML report.
clockwork
A fake clock library for Go that makes testing time-dependent code deterministic and fast.
mock
The rolling backport of Python's unittest.mock library
pytest-docker
Pytest fixtures that spin up Docker Compose services for integration tests, then tear them down automatically.
pytest-icdiff
A pytest plugin for clearer, colorized side-by-side assertion diffs.
approx
Approximate floating point equality comparisons and assertions for Rust
assert-json-diff
Compare two serializable values by diffing their JSON and get clear, precise error output.
toxiproxy
A TCP proxy for injecting network and system failures to test how applications handle unreliable dependencies.
