joshuarli-pytest-parallel 0.1.0

Small static-sharding parallel runner for pytest

pytest-parallel

A small pytest plugin for static process-level sharding.

pytest

Parallel execution is enabled by default. The default job count is auto, using os.cpu_count().

pytest -j 4
pytest --jobs 4
pytest --serial

Model

pytest-parallel keeps the execution model intentionally plain:

• collect once in the coordinator
• group tests by file
• assign files round-robin to fixed workers
• run each worker in a separate multiprocessing process
• report results through simple JSONL files

There is no work stealing, no execnet, no remote execution, and no scheduler protocol.

Platform Policy

• macOS uses spawn
• Linux uses fork
• other platforms use spawn

The fork/spawn point is after collection and before coordinator result polling begins.

On Linux, pytest-parallel refuses to fork if any non-main thread is alive at that point. That catches plugins that start background threads during configure, session start, collection, or pytest_parallel_pre_spawn.