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.github/workflows/hvd-tests.yml

@@ -81,7 +81,7 @@ jobs:
           timeout_minutes: 15
           shell: bash
           command: bash tests/run_cpu_tests.sh
-          new_command_on_retry: USE_LAST_FAILED=1   bash tests/run_cpu_tests.sh
+          new_command_on_retry: USE_LAST_FAILED=1 bash tests/run_cpu_tests.sh
 
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v3

.github/workflows/pytorch-version-tests.yml

@@ -98,7 +98,7 @@ jobs:
           timeout_minutes: 15
           shell: bash
           command: bash tests/run_cpu_tests.sh "not test_time_profilers"
-          new_command_on_retry: USE_LAST_FAILED=1  bash tests/run_cpu_tests.sh "not test_time_profilers"
+          new_command_on_retry: USE_LAST_FAILED=1 bash tests/run_cpu_tests.sh "not test_time_profilers"
 
   # create-issue:
   #   runs-on: ubuntu-latest

.github/workflows/tpu-tests.yml

@@ -97,7 +97,7 @@ jobs:
           command: |
             python -c "import torch_xla; print('torch xla version:', torch_xla.__version__)"
             bash tests/run_tpu_tests.sh
-          new_command_on_retry: USE_LAST_FAILED=1  bash tests/run_tpu_tests.sh
+          new_command_on_retry: USE_LAST_FAILED=1 bash tests/run_tpu_tests.sh
         env:
           LD_LIBRARY_PATH: ${{ env.LD_LIBRARY_PATH }}:${{ env.Python_ROOT_DIR }}/lib
           XRT_DEVICE_MAP: "CPU:0;/job:localservice/replica:0/task:0/device:XLA_CPU:0"

.github/workflows/unit-tests.yml

@@ -126,7 +126,7 @@ jobs:
           timeout_minutes: 15
           shell: bash
           command: SKIP_DISTRIB_TESTS=${{ matrix.skip-distrib-tests }} bash tests/run_cpu_tests.sh
-          new_command_on_retry: USE_LAST_FAILED=1  SKIP_DISTRIB_TESTS=${{ matrix.skip-distrib-tests }} bash tests/run_cpu_tests.sh
+          new_command_on_retry: USE_LAST_FAILED=1 SKIP_DISTRIB_TESTS=${{ matrix.skip-distrib-tests }} bash tests/run_cpu_tests.sh
 
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v3

tests/ignite/conftest.py

@@ -15,33 +15,51 @@
 import ignite.distributed as idist
 
 
-def pytest_configure(config):
-    config.addinivalue_line("markers", "distributed: run distributed")
-    config.addinivalue_line("markers", "multinode_distributed: distributed")
-    config.addinivalue_line("markers", "tpu: run on tpu")
-    if config.option.treat_unrun_as_failed:
-        unrun_tracker = UnrunTracker()
-        config.pluginmanager.register(unrun_tracker, "unrun_tracker_plugin")
-
-
 def pytest_addoption(parser):
+    """
+    Add custom command line options for the ignite test suite here.
+    See:
+    This function is a pytest hook (due to its name) and is *"automatically"
+    executed at the start of a test run
+    https://docs.pytest.org/en/latest/reference/reference.html#initialization-hooks
+
+    * "automatically" is true provided this conftest.py file is the
+    root directory. See:
+    https://docs.pytest.org/en/latest/reference/customize.html#initialization-determining-rootdir-and-configfile
+    """
     parser.addoption(
         "--treat-unrun-as-failed",
         action="store_true",
         help="""
-        If a session is interrupted treat the unrun tests as failed so that a
+        If a session is interrupted, treat the unrun tests as failed so that a
         rerun with --last-failed runs any tests that have not passed or been
-        skipped.
+        skipped. Note that if all tests in a module have been skipped, the
+        module will be skipped for all subsequent runs.
         """,
     )
 
 
+def pytest_configure(config):
+    """
+    This function is a pytest hook (due to its name) and is run after command
+    line parsing is complete in order to configure the test session.
+    """
+    config.addinivalue_line("markers", "distributed: run distributed")
+    config.addinivalue_line("markers", "multinode_distributed: distributed")
+    config.addinivalue_line("markers", "tpu: run on tpu")
+    if config.option.treat_unrun_as_failed:
+        unrun_tracker = UnrunTracker()
+        config.pluginmanager.register(unrun_tracker, "unrun_tracker_plugin")
+
+
 @pytest.fixture(scope="session", autouse=True)
 def term_handler():
-    # This allows the pytest session to be terminated upon retries on CI. It may
-    # be worth using this fixture solely in that context. For a discussion on
-    # whether sigterm should be ignored see:
-    # https://github.com/pytest-dev/pytest/issues/5243
+    """
+    This allows the pytest session to be terminated upon retries on CI. It may
+    be worth using this fixture solely in that context. For a discussion on
+    whether sigterm should be ignored and why pytest usually ignores it see:
+    https://github.com/pytest-dev/pytest/issues/5243
+    """
     if threading.current_thread() is threading.main_thread() and hasattr(signal, "SIGTERM"):
         orig = signal.signal(signal.SIGTERM, signal.getsignal(signal.SIGINT))
         yield
@@ -480,10 +498,13 @@ def distributed(request, local_rank, world_size):
 
 class UnrunTracker:
     """
-    Keeps track of unrun tests to improve the user experience when a test
-    session is interrupted. This is particularly useful on CI when rerunning
-    "failing" tests where the failure was due to a deadlock and many tests
-    weren't actually run so they didn't actually fail.
+    Keeps track of unrun tests to improve the user experience when using the
+    "--last-failed" pytest option and a test session is interrupted. This is
+    particularly useful on CI when rerunning "failing" tests where the failure
+    was due to a deadlock and many tests weren't actually run so they didn't
+    actually fail. This is a pytest plugin that implements some standard hooks
+    to modify the test session. Its functionality can be added to a test session
+    by registering it with the pytest plugin manager.
     """
 
     def __init__(self):
@@ -573,6 +594,13 @@ def xla_worker(index, fn):
 
 
 def pytest_sessionfinish(session, exitstatus):
+    """
+    Any functionality that should be run at the end of the session should be
+    added here.
+    This is a pytest hook (due to its name) and is called after the whole test
+    run finished, right before returning the exit status to the system.
+    """
+    # If requested by the user, track all unrun tests and add them to the lastfailed cache
     if session.config.option.treat_unrun_as_failed:
         unrun_tracker = session.config.pluginmanager.get_plugin("unrun_tracker_plugin")
         unrun_tracker.record_unrun_as_failed(session, exitstatus)