Simplify warnings testing

tests/test_fields.py

@@ -2,7 +2,6 @@ import datetime
 import os
 import re
 import uuid
-import warnings
 from decimal import ROUND_DOWN, ROUND_UP, Decimal
 
 import pytest
@@ -702,23 +701,17 @@ class TestNullableBooleanField(TestBooleanField):
 
 
 class TestNullBooleanField(TestCase):
+    @pytest.mark.filterwarnings('ignore::rest_framework.RemovedInDRF314Warning')
     def test_allow_null(self):
         msg = '`allow_null` is not a valid option.'
-
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', rest_framework.RemovedInDRF314Warning)
-            with self.assertRaisesMessage(AssertionError, msg):
-                serializers.NullBooleanField(allow_null=False)
+        with self.assertRaisesMessage(AssertionError, msg):
+            serializers.NullBooleanField(allow_null=False)
 
     def test_deprecation_warning(self):
-        with warnings.catch_warnings(record=True) as w:
-            warnings.simplefilter('always', rest_framework.RemovedInDRF314Warning)
+        msg = r"^The `NullBooleanField` is deprecated"
+        with self.assertWarnsRegex(rest_framework.RemovedInDRF314Warning, msg):
             serializers.NullBooleanField()
 
-        self.assertEqual(len(w), 1)
-        self.assertIs(w[0].category, rest_framework.RemovedInDRF314Warning)
-        self.assertIn("The `NullBooleanField` is deprecated", str(w[0].message))
-
 
 # String types...
 

tests/test_metadata.py

@@ -1,5 +1,3 @@
-import warnings
-
 import pytest
 from django.core.validators import MaxValueValidator, MinValueValidator
 from django.db import models
@@ -314,8 +312,7 @@ class TestMetadata:
 class TestSimpleMetadataFieldInfo(TestCase):
     def test_null_boolean_field_info_type(self):
         options = metadata.SimpleMetadata()
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', RemovedInDRF314Warning)
+        with self.assertWarns(RemovedInDRF314Warning):
             field = serializers.NullBooleanField()
         field_info = options.get_field_info(field)
         assert field_info['type'] == 'boolean'