Replaced django.test.utils.patch_logger() with assertLogs().

Thanks Tim Graham for the review.

tests/gis_tests/geoadmin/tests.py

@@ -1,7 +1,6 @@
 from django.contrib.gis import admin
 from django.contrib.gis.geos import Point
 from django.test import TestCase, override_settings
-from django.test.utils import patch_logger
 
 from .admin import UnmodifiableAdmin
 from .models import City, site
@@ -73,28 +72,28 @@ class GeoAdminTest(TestCase):
     def test_olwidget_empty_string(self):
         geoadmin = site._registry[City]
         form = geoadmin.get_changelist_form(None)({'point': ''})
-        with patch_logger('django.contrib.gis', 'error') as logger_calls:
-            output = str(form['point'])
+        with self.assertRaisesMessage(AssertionError, 'no logs'):
+            with self.assertLogs('django.contrib.gis', 'ERROR'):
+                output = str(form['point'])
         self.assertInHTML(
             '<textarea id="id_point" class="vWKTField required" cols="150"'
             ' rows="10" name="point"></textarea>',
             output
         )
-        self.assertEqual(logger_calls, [])
 
     def test_olwidget_invalid_string(self):
         geoadmin = site._registry[City]
         form = geoadmin.get_changelist_form(None)({'point': 'INVALID()'})
-        with patch_logger('django.contrib.gis', 'error') as logger_calls:
+        with self.assertLogs('django.contrib.gis', 'ERROR') as cm:
             output = str(form['point'])
         self.assertInHTML(
             '<textarea id="id_point" class="vWKTField required" cols="150"'
             ' rows="10" name="point"></textarea>',
             output
         )
-        self.assertEqual(len(logger_calls), 1)
+        self.assertEqual(len(cm.records), 1)
         self.assertEqual(
-            logger_calls[0],
+            cm.records[0].getMessage(),
             "Error creating geometry from value 'INVALID()' (String input "
             "unrecognized as WKT EWKT, and HEXEWKB.)"
         )

tests/gis_tests/test_geoforms.py

@@ -5,7 +5,6 @@ from django.contrib.gis.forms import BaseGeometryWidget, OpenLayersWidget
 from django.contrib.gis.geos import GEOSGeometry
 from django.forms import ValidationError
 from django.test import SimpleTestCase, override_settings
-from django.test.utils import patch_logger
 from django.utils.html import escape
 
 
@@ -120,7 +119,7 @@ class GeometryFieldTest(SimpleTestCase):
             'pt3': 'PNT(0)',  # invalid
         })
 
-        with patch_logger('django.contrib.gis', 'error') as logger_calls:
+        with self.assertLogs('django.contrib.gis', 'ERROR') as logger_calls:
             output = str(form)
 
         # The first point can't use assertInHTML() due to non-deterministic
@@ -142,9 +141,9 @@ class GeometryFieldTest(SimpleTestCase):
         )
         # Only the invalid PNT(0) triggers an error log entry.
         # Deserialization is called in form clean and in widget rendering.
-        self.assertEqual(len(logger_calls), 2)
+        self.assertEqual(len(logger_calls.records), 2)
         self.assertEqual(
-            logger_calls[0],
+            logger_calls.records[0].getMessage(),
             "Error creating geometry from value 'PNT(0)' (String input "
             "unrecognized as WKT EWKT, and HEXEWKB.)"
         )