Fixed #26215 -- Fixed RangeField/ArrayField serialization with None values

Also added tests for HStoreField and JSONField.
Thanks Aleksey Bukin for the report and Tim Graham for the initial patch and
the review.

django/contrib/postgres/fields/array.py

@@ -106,8 +106,11 @@ class ArrayField(Field):
         base_field = self.base_field
 
         for val in vals:
-            obj = AttributeSetter(base_field.attname, val)
-            values.append(base_field.value_to_string(obj))
+            if val is None:
+                values.append(None)
+            else:
+                obj = AttributeSetter(base_field.attname, val)
+                values.append(base_field.value_to_string(obj))
         return json.dumps(values)
 
     def get_transform(self, name):

django/contrib/postgres/fields/ranges.py

@@ -51,8 +51,12 @@ class RangeField(models.Field):
         base_field = self.base_field
         result = {"bounds": value._bounds}
         for end in ('lower', 'upper'):
-            obj = AttributeSetter(base_field.attname, getattr(value, end))
-            result[end] = base_field.value_to_string(obj)
+            val = getattr(value, end)
+            if val is None:
+                result[end] = None
+            else:
+                obj = AttributeSetter(base_field.attname, val)
+                result[end] = base_field.value_to_string(obj)
         return json.dumps(result)
 
     def formfield(self, **kwargs):

docs/releases/1.8.10.txt

@@ -17,3 +17,7 @@ Bugfixes
 
 * Made ``forms.FileField`` and ``utils.translation.lazy_number()`` picklable
   (:ticket:`26212`).
+
+* Fixed :class:`~django.contrib.postgres.fields.RangeField` and
+  :class:`~django.contrib.postgres.fields.ArrayField` serialization with
+  ``None`` values (:ticket:`26215`).

docs/releases/1.9.3.txt

@@ -27,3 +27,7 @@ Bugfixes
 
 * Made ``forms.FileField`` and ``utils.translation.lazy_number()`` picklable
   (:ticket:`26212`).
+
+* Fixed :class:`~django.contrib.postgres.fields.RangeField` and
+  :class:`~django.contrib.postgres.fields.ArrayField` serialization with
+  ``None`` values (:ticket:`26215`).

tests/postgres_tests/test_array.py

@@ -448,17 +448,17 @@ class TestMigrations(TransactionTestCase):
 
 class TestSerialization(PostgreSQLTestCase):
     test_data = (
-        '[{"fields": {"field": "[\\"1\\", \\"2\\"]"}, "model": "postgres_tests.integerarraymodel", "pk": null}]'
+        '[{"fields": {"field": "[\\"1\\", \\"2\\", null]"}, "model": "postgres_tests.integerarraymodel", "pk": null}]'
     )
 
     def test_dumping(self):
-        instance = IntegerArrayModel(field=[1, 2])
+        instance = IntegerArrayModel(field=[1, 2, None])
         data = serializers.serialize('json', [instance])
         self.assertEqual(json.loads(data), json.loads(self.test_data))
 
     def test_loading(self):
         instance = list(serializers.deserialize('json', self.test_data))[0].object
-        self.assertEqual(instance.field, [1, 2])
+        self.assertEqual(instance.field, [1, 2, None])
 
 
 class TestValidation(PostgreSQLTestCase):

tests/postgres_tests/test_hstore.py

@@ -165,7 +165,8 @@ class TestQuerying(PostgreSQLTestCase):
 
 
 class TestSerialization(PostgreSQLTestCase):
-    test_data = '[{"fields": {"field": "{\\"a\\": \\"b\\"}"}, "model": "postgres_tests.hstoremodel", "pk": null}]'
+    test_data = ('[{"fields": {"field": "{\\"a\\": \\"b\\"}"}, '
+                 '"model": "postgres_tests.hstoremodel", "pk": null}]')
 
     def test_dumping(self):
         instance = HStoreModel(field={'a': 'b'})
@@ -176,6 +177,12 @@ class TestSerialization(PostgreSQLTestCase):
         instance = list(serializers.deserialize('json', self.test_data))[0].object
         self.assertEqual(instance.field, {'a': 'b'})
 
+    def test_roundtrip_with_null(self):
+        instance = HStoreModel(field={'a': 'b', 'c': None})
+        data = serializers.serialize('json', [instance])
+        new_instance = list(serializers.deserialize('json', data))[0].object
+        self.assertEqual(instance.field, new_instance.field)
+
 
 class TestValidation(PostgreSQLTestCase):
 

tests/postgres_tests/test_json.py

@@ -213,16 +213,16 @@ class TestQuerying(TestCase):
 
 @skipUnlessPG94
 class TestSerialization(TestCase):
-    test_data = '[{"fields": {"field": {"a": "b"}}, "model": "postgres_tests.jsonmodel", "pk": null}]'
+    test_data = '[{"fields": {"field": {"a": "b", "c": null}}, "model": "postgres_tests.jsonmodel", "pk": null}]'
 
     def test_dumping(self):
-        instance = JSONModel(field={'a': 'b'})
+        instance = JSONModel(field={'a': 'b', 'c': None})
         data = serializers.serialize('json', [instance])
         self.assertJSONEqual(data, self.test_data)
 
     def test_loading(self):
         instance = list(serializers.deserialize('json', self.test_data))[0].object
-        self.assertEqual(instance.field, {'a': 'b'})
+        self.assertEqual(instance.field, {'a': 'b', 'c': None})
 
 
 class TestValidation(PostgreSQLTestCase):

tests/postgres_tests/test_ranges.py

@@ -309,6 +309,17 @@ class TestSerialization(PostgreSQLTestCase):
         self.assertEqual(instance.dates, DateRange(self.lower_date, self.upper_date))
         self.assertEqual(instance.timestamps, DateTimeTZRange(self.lower_dt, self.upper_dt))
 
+    def test_serialize_range_with_null(self):
+        instance = RangesModel(ints=NumericRange(None, 10))
+        data = serializers.serialize('json', [instance])
+        new_instance = list(serializers.deserialize('json', data))[0].object
+        self.assertEqual(new_instance.ints, NumericRange(None, 10))
+
+        instance = RangesModel(ints=NumericRange(10, None))
+        data = serializers.serialize('json', [instance])
+        new_instance = list(serializers.deserialize('json', data))[0].object
+        self.assertEqual(new_instance.ints, NumericRange(10, None))
+
 
 class TestValidators(PostgreSQLTestCase):