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
Kind
Sort:Used by Most Apps
pytest
The Python testing framework that makes writing small tests easy and scales to complex functional test suites.
tempfile
A secure, cross-platform Rust library for temporary files and directories that clean up automatically on drop.
Criterion.rs
Statistics-driven microbenchmarking for Rust that reliably detects performance changes.
pluggy
The minimalist, production-ready plugin and hook system that powers pytest, tox, and devpi
similar
A dependency-free Rust diffing library with Myers, Patience, Histogram, and LCS algorithms
Faker
A Python library that generates realistic fake data for testing, seeding, and anonymizing datasets across 70+ locales.
libfuzzer-sys
Rust bindings to LLVM's libFuzzer for coverage-guided fuzz testing
hypothesis
Property-based testing for Python that generates edge cases and shrinks failures to their simplest reproducing example.
fake-useragent
Up-to-date user-agent string faker backed by a real-world browser usage database, bundled offline.
Testcontainers for Rust
Integration-test against throwaway Docker containers from within Rust
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
behave
A Python behavior-driven development framework that runs Gherkin feature files against step definitions written in plain Python.
testcontainers-python
Throwaway Docker containers for real integration tests, driven straight from Python.
enigo
Cross-platform keyboard and mouse input simulation for Rust on Linux, macOS, and Windows.
pytest-html
A pytest plugin that turns your test run into an interactive, shareable HTML report.
mock
The rolling backport of Python's unittest.mock library
approx
Approximate floating point equality comparisons and assertions for Rust
factory_boy
A versatile test fixtures replacement for Python, providing declarative factories for building complex test objects.
VCR.py
Record and replay HTTP interactions to speed up tests
libtest-mimic
Build a custom Rust test harness that looks and behaves like rustc's built-in test runner
DeepEval
A Pytest-like open-source framework for unit-testing and evaluating LLM applications with research-backed metrics.
pywinauto
A Python library that drives Windows GUI apps by sending mouse, keyboard, and text-based actions to dialogs and controls.
afl.rs
Fuzz-test Rust code with AFLplusplus using the afl crate's fuzz macros and cargo-afl tooling.
