Merge pull request #7571 from bluetech/logging-setlevel-handler-restore

logging: fix capture handler level not reset on teardown after caplog.set_level()

src/_pytest/logging.py

@@ -345,6 +345,7 @@ class LogCaptureFixture:
         """Creates a new funcarg."""
         self._item = item
         # dict of log name -> log level
+        self._initial_handler_level = None  # type: Optional[int]
         self._initial_logger_levels = {}  # type: Dict[Optional[str], int]
 
     def _finalize(self) -> None:
@@ -353,6 +354,8 @@ class LogCaptureFixture:
         This restores the log levels changed by :meth:`set_level`.
         """
         # restore log levels
+        if self._initial_handler_level is not None:
+            self.handler.setLevel(self._initial_handler_level)
         for logger_name, level in self._initial_logger_levels.items():
             logger = logging.getLogger(logger_name)
             logger.setLevel(level)
@@ -434,6 +437,7 @@ class LogCaptureFixture:
         # save the original log-level to restore it during teardown
         self._initial_logger_levels.setdefault(logger, logger_obj.level)
         logger_obj.setLevel(level)
+        self._initial_handler_level = self.handler.level
         self.handler.setLevel(level)
 
     @contextmanager

testing/logging/test_fixture.py

@@ -2,6 +2,7 @@ import logging
 
 import pytest
 from _pytest.logging import caplog_records_key
+from _pytest.pytester import Testdir
 
 logger = logging.getLogger(__name__)
 sublogger = logging.getLogger(__name__ + ".baz")
@@ -27,8 +28,11 @@ def test_change_level(caplog):
     assert "CRITICAL" in caplog.text
 
 
-def test_change_level_undo(testdir):
+def test_change_level_undo(testdir: Testdir) -> None:
-    """Ensure that 'set_level' is undone after the end of the test"""
+    """Ensure that 'set_level' is undone after the end of the test.
+
+    Tests the logging output themselves (affacted both by logger and handler levels).
+    """
     testdir.makepyfile(
         """
         import logging
@@ -50,6 +54,33 @@ def test_change_level_undo(testdir):
     result.stdout.no_fnmatch_line("*log from test2*")
 
 
+def test_change_level_undos_handler_level(testdir: Testdir) -> None:
+    """Ensure that 'set_level' is undone after the end of the test (handler).
+
+    Issue #7569. Tests the handler level specifically.
+    """
+    testdir.makepyfile(
+        """
+        import logging
+
+        def test1(caplog):
+            assert caplog.handler.level == 0
+            caplog.set_level(41)
+            assert caplog.handler.level == 41
+
+        def test2(caplog):
+            assert caplog.handler.level == 0
+
+        def test3(caplog):
+            assert caplog.handler.level == 0
+            caplog.set_level(43)
+            assert caplog.handler.level == 43
+    """
+    )
+    result = testdir.runpytest()
+    result.assert_outcomes(passed=3)
+
+
 def test_with_statement(caplog):
     with caplog.at_level(logging.INFO):
         logger.debug("handler DEBUG level")