Add support to skip tests from CLI

With this patch, a new pytest optional arg has been added:
--skipregex

When it is used, tests are skipped when the regex is found in their test
names. Fully qualified test names are used for this search. Example:
tobiko.tests.unit.test_exception.TestException.test_init

It can be used from CLI with pytest like this:
$ .tox/py3/bin/pytest \
  --skipregex='test_join_chunks_.*_bytes|test_join_chunks_with_unicodes' \
  tobiko/tests/unit

It can be used from CLI with tox like this:
$ PYTEST_ADDOPTS="--skipregex='test_join_chunks_.*_bytes|test_join_chunks_with_unicodes'" \
  TOX_PYTHON=python3.9 \
  tox -e py3

It can be used from the Tobiko Infrared plugin by using the following
option (limitation: the skipregex is applied to all the steps from the
the executed Tobiko workflow):
$ infrared tobiko ... --pytest-addopts "--skipregex='test_join_chunks_.*_bytes|test_join_chunks_with_unicodes'"

It can be used from a zuul job by configuring the following variable
within the zuul job yaml file (limitation: the skipregex is applied to
all the steps from the executed Tobiko workflow):
pytest_addopts_global: "--skipregex='test_join_chunks_.*_bytes|test_join_chunks_with_unicodes'"

Change-Id: I8ee32ba467bd70142816953598d1736fa353d3d0

infrared_plugin/plugin.spec

@@ -202,8 +202,10 @@ subparsers:
             ansible_variable: tox_python
           pytest-addopts:
             type: Value
-            help: Extra options to be passed to PyTest
+            help: >
-            ansible_variable: pytest_addopts
+                Extra options to be passed to PyTest. This value is overriden
+                when it is defined at workflow level too.
+            ansible_variable: pytest_addopts_global
           pytest-markers:
             type: Value
             help: >

releasenotes/notes/skipregex-new-arg-a9f1c001cbc823f9.yaml

@@ -0,0 +1,36 @@
+---
+features:
+  - |
+    Added new input argument `--skipregex`
+    When it is used, tests are skipped when the regex is found in their test
+    names. Fully qualified test names are used for this search.
+
+    | Example: tobiko.tests.unit.test_exception.TestException.test_init
+
+    * It can be used from CLI with pytest
+
+    .. code-block:: text
+
+      $ .tox/py3/bin/pytest --skipregex='test_join_chunks_.*_bytes|test_join_chunks_with_unicodes' tobiko/tests/unit
+
+    * It can be used from CLI with tox
+
+    .. code-block:: text
+
+      $ PYTEST_ADDOPTS="--skipregex='test_join_chunks_.*_bytes|test_join_chunks_with_unicodes'" TOX_PYTHON=python3.9 tox -e py3
+
+    * It can be used from the Tobiko Infrared plugin by using the --pytest-addopts
+      option (limitation: the skipregex is applied to all the steps from the
+      the executed Tobiko workflow)
+
+    .. code-block:: text
+
+      $ infrared tobiko ... --pytest-addopts "--skipregex='test_join_chunks_.*_bytes|test_join_chunks_with_unicodes'"
+
+    * It can be used from a zuul job by configuring the following variable
+      within the zuul job yaml file (limitation: the skipregex is applied to
+      all the steps from the executed Tobiko workflow)
+
+    .. code-block:: text
+
+      pytest_addopts_global: "--skipregex='test_join_chunks_.*_bytes|test_join_chunks_with_unicodes'"

roles/tobiko-tox/defaults/main.yaml

@@ -36,7 +36,8 @@ tox_expected_rcs:
   - '{{ tox_succeeded_rc }}'
 ignore_test_failures: no
 
-pytest_addopts: ''
+pytest_addopts: '{{ pytest_addopts_global }}'
+pytest_addopts_global: ''
 pytest_markers: "{% if not test_flaky%}not flaky{% endif %}"
 pytest_maxfail: ''
 test_flaky: false

roles/tobiko-tox/tasks/tox.yaml

@@ -50,7 +50,7 @@
 
 - name: reset values used to generate tox_constrain_env after executing a test suite
   set_fact:
-    pytest_addopts: ''
+    pytest_addopts: '{{ pytest_addopts_global }}'
     test_flaky: false
     pytest_markers: "{% if not test_flaky%}not flaky{% endif %}"
     pytest_maxfail: ''

tobiko/tests/conftest.py

@@ -16,6 +16,7 @@ from __future__ import absolute_import
 
 from datetime import datetime
 import os
+import re
 import subprocess
 
 from oslo_log import log
@@ -172,3 +173,21 @@ def pytest_runtest_call(item):
 @pytest.fixture(scope="session", autouse=True)
 def cleanup_shelves():
     tobiko.initialize_shelves()
+
+
+def pytest_addoption(parser):
+    parser.addoption("--skipregex", action="store",
+                     default="", help="skip tests matching the provided regex")
+
+
+def pytest_collection_modifyitems(config, items):
+    skipregex = config.getoption("--skipregex")
+    if not skipregex:
+        # --skipregex not given in cli, therefore move on
+        return
+    skip_listed = pytest.mark.skip(reason="matches --skipregex")
+    for item in items:
+        fully_qualified_test_name = '.'.join([item.obj.__module__,
+                                              item.getmodpath()])
+        if re.search(skipregex, fully_qualified_test_name):
+            item.add_marker(skip_listed)