ansible/test/lib/ansible_test/_util/target/pytest/plugins/ansible_pytest_collections.py

"""Enable unit testing of Ansible collections. PYTEST_DONT_REWRITE"""
from __future__ import annotations

import os

# set by ansible-test to a single directory, rather than a list of directories as supported by Ansible itself
ANSIBLE_COLLECTIONS_PATH = os.path.join(os.environ['ANSIBLE_COLLECTIONS_PATH'], 'ansible_collections')

# set by ansible-test to the minimum python version supported on the controller
ANSIBLE_CONTROLLER_MIN_PYTHON_VERSION = tuple(int(x) for x in os.environ['ANSIBLE_CONTROLLER_MIN_PYTHON_VERSION'].split('.'))


# this monkeypatch to _pytest.pathlib.resolve_package_path fixes PEP420 resolution for collections in pytest >= 6.0.0
# NB: this code should never run under py2
def collection_resolve_package_path(path):
    """Configure the Python package path so that pytest can find our collections."""
    for parent in path.parents:
        if str(parent) == ANSIBLE_COLLECTIONS_PATH:
            return parent

    raise Exception('File "%s" not found in collection path "%s".' % (path, ANSIBLE_COLLECTIONS_PATH))


# this monkeypatch to py.path.local.LocalPath.pypkgpath fixes PEP420 resolution for collections in pytest < 6.0.0
def collection_pypkgpath(self):
    """Configure the Python package path so that pytest can find our collections."""
    for parent in self.parts(reverse=True):
        if str(parent) == ANSIBLE_COLLECTIONS_PATH:
            return parent

    raise Exception('File "%s" not found in collection path "%s".' % (self.strpath, ANSIBLE_COLLECTIONS_PATH))


def enable_assertion_rewriting_hook():  # type: () -> None
    """
    Enable pytest's AssertionRewritingHook on Python 3.x.
    This is necessary because the Ansible collection loader intercepts imports before the pytest provided loader ever sees them.
    """
    import sys

    if sys.version_info[0] == 2:
        return  # Python 2.x is not supported

    hook_name = '_pytest.assertion.rewrite.AssertionRewritingHook'
    hooks = [hook for hook in sys.meta_path if hook.__class__.__module__ + '.' + hook.__class__.__qualname__ == hook_name]

    if len(hooks) != 1:
        raise Exception('Found {} instance(s) of "{}" in sys.meta_path.'.format(len(hooks), hook_name))

    assertion_rewriting_hook = hooks[0]

    # This is based on `_AnsibleCollectionPkgLoaderBase.exec_module` from `ansible/utils/collection_loader/_collection_finder.py`.
    def exec_module(self, module):
        # short-circuit redirect; avoid reinitializing existing modules
        if self._redirect_module:  # pylint: disable=protected-access
            return

        # execute the module's code in its namespace
        code_obj = self.get_code(self._fullname)  # pylint: disable=protected-access

        if code_obj is not None:  # things like NS packages that can't have code on disk will return None
            # This logic is loosely based on `AssertionRewritingHook._should_rewrite` from pytest.
            # See: https://github.com/pytest-dev/pytest/blob/779a87aada33af444f14841a04344016a087669e/src/_pytest/assertion/rewrite.py#L209
            should_rewrite = self._package_to_load == 'conftest' or self._package_to_load.startswith('test_')  # pylint: disable=protected-access

            if should_rewrite:
                # noinspection PyUnresolvedReferences
                assertion_rewriting_hook.exec_module(module)
            else:
                exec(code_obj, module.__dict__)  # pylint: disable=exec-used

    # noinspection PyProtectedMember
    from ansible.utils.collection_loader._collection_finder import _AnsibleCollectionPkgLoaderBase

    _AnsibleCollectionPkgLoaderBase.exec_module = exec_module


def pytest_configure():
    """Configure this pytest plugin."""
    try:
        if pytest_configure.executed:
            return
    except AttributeError:
        pytest_configure.executed = True

    enable_assertion_rewriting_hook()

    # noinspection PyProtectedMember
    from ansible.utils.collection_loader._collection_finder import _AnsibleCollectionFinder

    # allow unit tests to import code from collections

    # noinspection PyProtectedMember
    _AnsibleCollectionFinder(paths=[os.path.dirname(ANSIBLE_COLLECTIONS_PATH)])._install()  # pylint: disable=protected-access

    try:
        # noinspection PyProtectedMember
        from _pytest import pathlib as _pytest_pathlib
    except ImportError:
        _pytest_pathlib = None

    if hasattr(_pytest_pathlib, 'resolve_package_path'):
        _pytest_pathlib.resolve_package_path = collection_resolve_package_path
    else:
        # looks like pytest <= 6.0.0, use the old hack against py.path
        # noinspection PyProtectedMember
        import py._path.local

        # force collections unit tests to be loaded with the ansible_collections namespace
        # original idea from https://stackoverflow.com/questions/50174130/how-do-i-pytest-a-project-using-pep-420-namespace-packages/50175552#50175552
        # noinspection PyProtectedMember
        py._path.local.LocalPath.pypkgpath = collection_pypkgpath  # pylint: disable=protected-access


pytest_configure()