Cannot run a specific test after pytest migration

[Akihiro Motoki]

After pytest migration, we cannot run a specific test explicitly.

Previously we can use

  tox -e py37 -- openstack_auth.test.unit.test_policy

to run only tests under openstack_auth/test/unit/test_policy.py.

After the pytest migration, tools/unit_test.sh only honors the module name like openstack_dashboard, horizon, openstack_auth.
This is a regression during the pytest migration.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/723134

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/723134
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=ccaaf8cbb928693a6db317cf19ac39ec7a47a832
Submitter: Zuul
Branch: master

commit ccaaf8cbb928693a6db317cf19ac39ec7a47a832
Author: Akihiro Motoki <email address hidden>
Date: Sun Apr 26 14:07:16 2020 +0900

    Fix regressions in unit_tests.sh during pytest mirgation

    The pytest migration patch introduced a couple of regression in
    tools/unit_tests.sh:

    * We no longer cannot run a specific test explicitly
      (per python file, per test class, per specific test).
      Per module like openstack_dashboard, openstack_auth and horizon
      is the only possible way after the pytest migration.
    * openstack_dashboard tests outside of openstack_dashboard/test/
      are not looked up when a subset is specified.

    This commit restores the orginal behavior.

    pytest uses a different way to specify tests.
    We cannot use the style of python modules like
    "openstack_auth.tests.unit.test_policy.PolicyLoaderTestCase.test_policy_file_load"
    and we need to specify tests like file paths [1].

    [1] https://docs.pytest.org/en/latest/usage.html#specifying-tests-selecting-tests

    Closes-Bug: #1875123
    Change-Id: Ic4b6c69d8a2ed774cce16521c4c4336f55ff737e