Registry / testing / pytest-threadleak

pytest-threadleak

library0.5.0pypypiunverified

pytest-threadleak is a pytest plugin that automatically detects non-daemon thread leaks after tests complete. It helps identify when tests leave background threads running, which can cause resource exhaustion or unexpected behavior. The current version is 0.5.0, and it is maintained with releases as needed for bug fixes or new features.

testing

pip install pytest-threadleak pytest

github ↗package ↗

INSTALL

IMPORT

SIG · PYTEST-THREADLEAK

pytest-threadleak

testingpythonv0.5.0

Install

2.6s avg

Import

—

Disk

29MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.5.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.910 runs

installs and imports cleanly · install 0.0s · import 0.000s · 30.7MB

glibc

py 3.10–3.910 runs

installs and imports cleanly · install 2.6s · import 0.000s · 31MB

29MB installed

● package 29MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

threadleak

✓ def test_something(threadleak): ...

✗ from pytest_threadleak import threadleak

pytest-threadleak provides fixtures, not direct module imports for its core functionality. The 'threadleak' fixture is automatically discovered and injected by pytest.

To get started, simply install `pytest-threadleak` and include the `threadleak` fixture in your test functions. The plugin automatically checks for new non-daemon threads spawned during the test that are still active when the test finishes. The example demonstrates a clean test and how to intentionally create a leak to see the plugin in action.

import threading import time # test_my_app.py def test_my_function_no_leak(threadleak): """ This test uses the 'threadleak' fixture to ensure no new non-daemon threads are left running after the test completes. This specific test should pass cleanly. """ def do_something_brief(): time.sleep(0.01) t = threading.Thread(target=do_something_brief) t.start() t.join() # Ensure the thread finishes before the test does # To run this test: # pip install pytest-threadleak pytest # pytest test_my_app.py # To observe a leak (uncomment and run): # def test_my_function_with_leak(threadleak): # """ # This test will intentionally leave a non-daemon thread running, # causing pytest-threadleak to report a ThreadLeakError. # """ # def infinite_loop(): # while True: # time.sleep(0.1) # # threading.Thread(target=infinite_loop).start()

Debug

Known issues

breakingPython 2 support was dropped in version 0.3.0. Users on Python 2 must use an older version.

fix

Upgrade to Python 3 or restrict pytest-threadleak version to 0.2.0 or earlier if Python 2 is strictly required (not recommended for new projects).

affects: <=0.2.0

gotchapytest-threadleak only detects threads that are *still running* and are *not daemon threads* after a test. Threads that complete and join successfully before the test ends will not be flagged. Daemon threads are also ignored by default.

fix

Ensure all non-daemon threads are explicitly joined or terminated within the test's scope. For long-running background threads that are expected, configure `threadleak_thread_name_patterns_to_ignore` in your `pytest.ini`.

affects: All

gotchaIf tests fail with `ThreadLeakError` for threads that are part of standard libraries or external packages (e.g., from `requests` or `concurrent.futures`), these threads might need to be explicitly ignored.

fix

Use the `threadleak_thread_name_patterns_to_ignore` option in your `pytest.ini` to specify regular expressions matching the names of threads that should be ignored, for example: `threadleak_thread_name_patterns_to_ignore = 'ThreadPoolExecutor.*'`.

affects: All

Upgrade

Version history

0.5.0latest on PyPI · released Jul 3, 2022

Audit

Dependencies

pytestrequiredpytest-threadleak is a plugin for the pytest testing framework and requires pytest to function.

Agent activity

11 hits · last 30 days

node

Amazon

Resources

githubhttps://github.com/nirs/pytest-threadleak ↗

packagehttps://pypi.org/project/pytest-threadleak/ ↗