Add a test to show a regression with RegexField

and compiled regex

tests/test_fields.py

@@ -1,5 +1,6 @@
 import datetime
 import os
+import re
 import uuid
 from decimal import Decimal
 
@@ -590,6 +591,20 @@ class TestRegexField(FieldValues):
     field = serializers.RegexField(regex='[a-z][0-9]')
 
 
+class TestiCompiledRegexField(FieldValues):
+    """
+    Valid and invalid values for `RegexField`.
+    """
+    valid_inputs = {
+        'a9': 'a9',
+    }
+    invalid_inputs = {
+        'A9': ["This value does not match the required pattern."]
+    }
+    outputs = {}
+    field = serializers.RegexField(regex=re.compile('[a-z][0-9]'))
+
+
 class TestSlugField(FieldValues):
     """
     Valid and invalid values for `SlugField`.

tests/test_serializer.py

@@ -2,6 +2,7 @@
 from __future__ import unicode_literals
 
 import pickle
+import re
 
 import pytest
 
@@ -337,3 +338,16 @@ class TestDefaultInclusions:
         assert serializer.is_valid()
         assert serializer.validated_data == {'integer': 456}
         assert serializer.errors == {}
+
+
+class TestSerializerValidationWithCompiledRegexField:
+    def setup(self):
+        class ExampleSerializer(serializers.Serializer):
+            name = serializers.RegexField(re.compile(r'\d'), required=True)
+        self.Serializer = ExampleSerializer
+
+    def test_validation_success(self):
+        serializer = self.Serializer(data={'name': '2'})
+        assert serializer.is_valid()
+        assert serializer.validated_data == {'name': '2'}
+        assert serializer.errors == {}