customdirectory.rst

Using a custom directory collector

By default, pytest collects directories using :class:`pytest.Package`, for directories with __init__.py files, and :class:`pytest.Dir` for other directories. If you want to customize how a directory is collected, you can write your own :class:`pytest.Directory` collector, and use 🪝`pytest_collect_directory` to hook it up.

A basic example for a directory manifest file

Suppose you want to customize how collection is done on a per-directory basis. Here is an example conftest.py plugin that allows directories to contain a manifest.json file, which defines how the collection should be done for the directory. In this example, only a simple list of files is supported, however you can imagine adding other keys, such as exclusions and globs.

You can create a manifest.json file and some test files:

An you can now execute the test specification:

customdirectory $ pytest
=========================== test session starts ============================
platform linux -- Python 3.x.y, pytest-9.x.y, pluggy-1.x.y
rootdir: /home/sweet/project/customdirectory
configfile: pytest.ini
collected 2 items

tests/test_first.py .                                                [ 50%]
tests/test_second.py .                                               [100%]

============================ 2 passed in 0.12s =============================

Notice how test_three.py was not executed, because it is not listed in the manifest.

You can verify that your custom collector appears in the collection tree:

customdirectory $ pytest --collect-only
=========================== test session starts ============================
platform linux -- Python 3.x.y, pytest-9.x.y, pluggy-1.x.y
rootdir: /home/sweet/project/customdirectory
configfile: pytest.ini
collected 2 items

<Dir customdirectory>
  <ManifestDirectory tests>
    <Module test_first.py>
      <Function test_1>
    <Module test_second.py>
      <Function test_2>

======================== 2 tests collected in 0.12s ========================