pytest-pitch

pytest_pitch

pytest_pitch runs tests in an order such that coverage increases as fast as possible. Typically 99% of the total coverage is achieved in 10% of the test session time.

use as pytest plugin for faster coverage increase

First create persistent time-coverage record via pytest-donde

python -m pytest [YOUR SESSION ARGS] --donde=/path/to/src

where /path/to/src is the code region to cover.

Then pass the record file to the plugin via

python -m pytest [YOUR SESSION ARGS] --pitch

If You change your test definitions or test selection [YOUR SESSION ARGS] in step 2 without updating the record:

• tests which are unknown to step 1 (e.g. newly defined tests, less strict test selection) will be put to the start of the execution order
• tests which are known to step 1 but missing in step 2 (e.g. removed tests, stricter test selection) will just be filtered out. Any selection mechanisms should not conflict with the reordering.

use in your script

See this script as a demo which was used to create the image shown above.

background

The plugin employs Algorithm 1 from p. 3 of S. Khuller, A. Moss, J. Naor, The budgeted maximum coverage problem, Inf. Process. Lett. 70, 1999.

install

python -m pip install pytest_pitch