Use caplog fixure rather than mock logging when testing HTEX shutdown (…

…#3559)

This replaces mock-captured call sequences which are over-testing the exact
position of tested log calls in relation to any other log calls, which makes
this test fragile when working on logs in the affected area of the code.

This is consistent with other parts of the test suite which test log messages
using caplog.

parsl/tests/test_htex/test_htex.py

@@ -71,12 +71,11 @@ def test_htex_start_encrypted(
 @pytest.mark.local
 @pytest.mark.parametrize("started", (True, False))
 @pytest.mark.parametrize("timeout_expires", (True, False))
-@mock.patch(f"{_MOCK_BASE}.logger")
 def test_htex_shutdown(
-    mock_logger: mock.MagicMock,
     started: bool,
     timeout_expires: bool,
     htex: HighThroughputExecutor,
+    caplog
 ):
     mock_ix_proc = mock.Mock(spec=Popen)
 
@@ -110,20 +109,19 @@ def kill_interchange(*args, **kwargs):
 
     htex.shutdown()
 
-    mock_logs = mock_logger.info.call_args_list
     if started:
         assert mock_ix_proc.terminate.called
         assert mock_ix_proc.wait.called
         assert {"timeout": 10} == mock_ix_proc.wait.call_args[1]
         if timeout_expires:
-            assert "Unable to terminate Interchange" in mock_logs[1][0][0]
+            assert "Unable to terminate Interchange" in caplog.text
             assert mock_ix_proc.kill.called
-        assert "Attempting" in mock_logs[0][0][0]
-        assert "Finished" in mock_logs[-1][0][0]
+        assert "Attempting HighThroughputExecutor shutdown" in caplog.text
+        assert "Finished HighThroughputExecutor shutdown" in caplog.text
     else:
         assert not mock_ix_proc.terminate.called
         assert not mock_ix_proc.wait.called
-        assert "has not started" in mock_logs[0][0][0]
+        assert "HighThroughputExecutor has not started" in caplog.text
 
 
 @pytest.mark.local