bpo-41906: Accept built filters in dictConfig (GH-30756)

When configuring the logging stack, accept already built filters (or
just callables) in the filters array of loggers and handlers.
This facilitates passing quick callables as filters.

Automerge-Triggered-By: GH:vsajip

2 files changed, 43 insertions, 1 deletions

diff --git a/Lib/logging/config.py b/Lib/logging/config.py
index 9bc07ed..86a1e4e 100644
--- a/Lib/logging/config.py
+++ b/Lib/logging/config.py
@@ -694,7 +694,11 @@ class DictConfigurator(BaseConfigurator):
         """Add filters to a filterer from a list of names."""
         for f in filters:
             try:
-                filterer.addFilter(self.config['filters'][f])
+                if callable(f) or callable(getattr(f, 'filter', None)):
+                    filter_ = f
+                else:
+                    filter_ = self.config['filters'][f]
+                filterer.addFilter(filter_)
             except Exception as e:
                 raise ValueError('Unable to add filter %r' % f) from e
 
diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index 7c38676..4f33151 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -3447,6 +3447,44 @@ class ConfigDictTest(BaseTest):
             logging.info('some log')
         self.assertEqual(stderr.getvalue(), 'some log my_type\n')
 
+    def test_config_callable_filter_works(self):
+        def filter_(_):
+            return 1
+        self.apply_config({
+            "version": 1, "root": {"level": "DEBUG", "filters": [filter_]}
+        })
+        assert logging.getLogger().filters[0] is filter_
+        logging.getLogger().filters = []
+
+    def test_config_filter_works(self):
+        filter_ = logging.Filter("spam.eggs")
+        self.apply_config({
+            "version": 1, "root": {"level": "DEBUG", "filters": [filter_]}
+        })
+        assert logging.getLogger().filters[0] is filter_
+        logging.getLogger().filters = []
+
+    def test_config_filter_method_works(self):
+        class FakeFilter:
+            def filter(self, _):
+                return 1
+        filter_ = FakeFilter()
+        self.apply_config({
+            "version": 1, "root": {"level": "DEBUG", "filters": [filter_]}
+        })
+        assert logging.getLogger().filters[0] is filter_
+        logging.getLogger().filters = []
+
+    def test_invalid_type_raises(self):
+        class NotAFilter: pass
+        for filter_ in [None, 1, NotAFilter()]:
+            self.assertRaises(
+                ValueError,
+                self.apply_config,
+                {"version": 1, "root": {"level": "DEBUG", "filters": [filter_]}}
+            )
+
+
 class ManagerTest(BaseTest):
     def test_manager_loggerclass(self):
         logged = []