account for logging-plugging being disabled

src/pytest_subtests.py

@@ -181,12 +181,15 @@ def _capturing_output(self):
     @contextmanager
     def _capturing_logs(self):
         logging_plugin = self.request.config.pluginmanager.getplugin("logging-plugin")
-        handler = LogCaptureHandler()
-        handler.setFormatter(logging_plugin.formatter)
-
-        captured_logs = CapturedLogs(handler)
-        with catching_logs(handler):
-            yield captured_logs
+        if logging_plugin is None:
+            yield NullCapturedLogs()
+        else:
+            handler = LogCaptureHandler()
+            handler.setFormatter(logging_plugin.formatter)
+
+            captured_logs = CapturedLogs(handler)
+            with catching_logs(handler):
+                yield captured_logs
 
     @contextmanager
     def test(self, msg=None, **kwargs):
@@ -211,8 +214,8 @@ def test(self, msg=None, **kwargs):
         sub_report = SubTestReport._from_test_report(report)
         sub_report.context = SubTestContext(msg, kwargs.copy())
 
-        captured.update_report(sub_report)
-        capturedlogs.update_report(sub_report)
+        captured_output.update_report(sub_report)
+        captured_logs.update_report(sub_report)
 
         with self.suspend_capture_ctx():
             self.ihook.pytest_runtest_logreport(report=sub_report)
@@ -259,12 +262,18 @@ def update_report(self, report):
         if self.err:
             report.sections.append(("Captured stderr call", self.err))
 
+
 class CapturedLogs:
     def __init__(self, handler):
         self._handler = handler
 
     def update_report(self, report):
         report.sections.append(("Captured log call", self._handler.stream.getvalue()))
+
+
+class NullCapturedLogs:   
+    def update_report(self, report):
+        pass
 
 
 def pytest_report_to_serializable(report):

tests/test_subtests.py

@@ -423,6 +423,32 @@ def test(subtests, caplog):
             ]
         )
 
+    def test_no_logging(self, testdir):
+        testdir.makepyfile(
+            """
+            import logging
+
+            def test(subtests):
+                logging.info("start log line")
+
+                with subtests.test("sub passing"):
+                    logging.info("inside %s", "passing log line")
+                
+                with subtests.test("sub failing"):
+                    logging.info("inside %s", "failing log line")
+                    assert False
+
+                logging.info("end log line")
+            """
+        )
+        result = testdir.runpytest("-p no:logging")
+        result.stdout.fnmatch_lines(
+            [
+                "*1 passed*",
+            ]
+        )
+        result.stdout.no_fnmatch_line("*root:test_no_logging.py*log line*")
+
 
 class TestDebugging:
     """Check --pdb support for subtests fixture and TestCase.subTest."""