Deserialise models without schema fix

openapi_core/schema/media_types/models.py

@@ -32,14 +32,14 @@ def deserialize(self, value):
         return deserializer(value)
 
     def cast(self, value):
-        if not self.schema:
-            return value
-
         try:
             deserialized = self.deserialize(value)
         except ValueError as exc:
             raise InvalidMediaTypeValue(exc)
 
+        if not self.schema:
+            return deserialized
+
         try:
             return self.schema.cast(deserialized)
         except CastError as exc:

openapi_core/schema/parameters/models.py

@@ -99,14 +99,14 @@ def cast(self, value):
                 not self.allow_empty_value):
             raise EmptyParameterValue(self.name)
 
-        if not self.schema:
-            return value
-
         try:
             deserialized = self.deserialize(value)
         except (ValueError, AttributeError) as exc:
             raise InvalidParameterValue(self.name, exc)
 
+        if not self.schema:
+            return deserialized
+
         try:
             return self.schema.cast(deserialized)
         except CastError as exc:

tests/unit/schema/test_media_types.py

@@ -1,3 +1,6 @@
+import pytest
+
+from openapi_core.schema.media_types.exceptions import InvalidMediaTypeValue
 from openapi_core.schema.media_types.models import MediaType
 
 
@@ -7,6 +10,13 @@ def test_empty(self):
         media_type = MediaType('application/json')
         value = ''
 
+        with pytest.raises(InvalidMediaTypeValue):
+            media_type.cast(value)
+
+    def test_no_schema_deserialised(self):
+        media_type = MediaType('application/json')
+        value = "{}"
+
         result = media_type.cast(value)
 
-        assert result == value
+        assert result == {}