From acab13fcc9f04940721b0a4aa39701100e376b00 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jens=20Tr=C3=B6ger?= <jenstroeger@users.noreply.github.com>
Date: Fri, 24 Nov 2023 22:38:34 +1000
Subject: [PATCH] Add new filtering() method to LogCaptureFixture class
 (#11625)

Fixes #11610
---
 AUTHORS                         |  1 +
 changelog/11610.feature.rst     |  2 ++
 src/_pytest/logging.py          | 16 ++++++++++++++++
 testing/logging/test_fixture.py | 22 ++++++++++++++++++++--
 4 files changed, 39 insertions(+), 2 deletions(-)
 create mode 100644 changelog/11610.feature.rst

diff --git a/AUTHORS b/AUTHORS
index e30131d1a..669ec537e 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -188,6 +188,7 @@ Javier Romero
 Jeff Rackauckas
 Jeff Widman
 Jenni Rinker
+Jens Tröger
 John Eddie Ayson
 John Litborn
 John Towler
diff --git a/changelog/11610.feature.rst b/changelog/11610.feature.rst
new file mode 100644
index 000000000..34df34705
--- /dev/null
+++ b/changelog/11610.feature.rst
@@ -0,0 +1,2 @@
+Added :func:`LogCaptureFixture.filtering() <pytest.LogCaptureFixture.filtering>` context manager that
+adds a given :class:`logging.Filter` object to the caplog fixture.
diff --git a/src/_pytest/logging.py b/src/_pytest/logging.py
index bacca4b2a..246a4ab6e 100644
--- a/src/_pytest/logging.py
+++ b/src/_pytest/logging.py
@@ -564,6 +564,22 @@ class LogCaptureFixture:
             self.handler.setLevel(handler_orig_level)
             logging.disable(original_disable_level)
 
+    @contextmanager
+    def filtering(self, filter_: logging.Filter) -> Generator[None, None, None]:
+        """Context manager that temporarily adds the given filter to the caplog's
+        :meth:`handler` for the 'with' statement block, and removes that filter at the
+        end of the block.
+
+        :param filter_: A custom :class:`logging.Filter` object.
+
+        .. versionadded:: 7.5
+        """
+        self.handler.addFilter(filter_)
+        try:
+            yield
+        finally:
+            self.handler.removeFilter(filter_)
+
 
 @fixture
 def caplog(request: FixtureRequest) -> Generator[LogCaptureFixture, None, None]:
diff --git a/testing/logging/test_fixture.py b/testing/logging/test_fixture.py
index 753cf5fcd..f4912aecc 100644
--- a/testing/logging/test_fixture.py
+++ b/testing/logging/test_fixture.py
@@ -144,7 +144,7 @@ def test_change_level_undos_handler_level(pytester: Pytester) -> None:
     result.assert_outcomes(passed=3)
 
 
-def test_with_statement(caplog: pytest.LogCaptureFixture) -> None:
+def test_with_statement_at_level(caplog: pytest.LogCaptureFixture) -> None:
     with caplog.at_level(logging.INFO):
         logger.debug("handler DEBUG level")
         logger.info("handler INFO level")
@@ -159,7 +159,9 @@ def test_with_statement(caplog: pytest.LogCaptureFixture) -> None:
     assert "CRITICAL" in caplog.text
 
 
-def test_with_statement_logging_disabled(caplog: pytest.LogCaptureFixture) -> None:
+def test_with_statement_at_level_logging_disabled(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
     logging.disable(logging.CRITICAL)
     assert logging.root.manager.disable == logging.CRITICAL
     with caplog.at_level(logging.WARNING):
@@ -185,6 +187,22 @@ def test_with_statement_logging_disabled(caplog: pytest.LogCaptureFixture) -> No
     assert logging.root.manager.disable == logging.CRITICAL
 
 
+def test_with_statement_filtering(caplog: pytest.LogCaptureFixture) -> None:
+    class TestFilter(logging.Filter):
+        def filter(self, record: logging.LogRecord) -> bool:
+            record.msg = "filtered handler call"
+            return True
+
+    with caplog.at_level(logging.INFO):
+        with caplog.filtering(TestFilter()):
+            logger.info("handler call")
+        logger.info("handler call")
+
+    filtered_tuple, unfiltered_tuple = caplog.record_tuples
+    assert filtered_tuple == ("test_fixture", 20, "filtered handler call")
+    assert unfiltered_tuple == ("test_fixture", 20, "handler call")
+
+
 @pytest.mark.parametrize(
     "level_str,expected_disable_level",
     [