Finish implementation of runtime type checks

And update tests/resolve to take info param.

Closes #57

Author: jhgg

graphql/core/execution/executor.py

@@ -260,19 +260,21 @@ def complete_value(self, ctx, return_type, field_asts, info, result):
             runtime_type = return_type
 
         elif isinstance(return_type, (GraphQLInterfaceType, GraphQLUnionType)):
-            runtime_type = return_type.resolve_type(result)
+            runtime_type = return_type.resolve_type(result, info)
             if runtime_type and not return_type.is_possible_type(runtime_type):
                 raise GraphQLError(
-                    'Runtime Object type "{}" is not a possible type for "{}".'.format(runtime_type, return_type),
+                    u'Runtime Object type "{}" is not a possible type for "{}".'.format(runtime_type, return_type),
                     field_asts
                 )
 
         if not runtime_type:
             return None
 
-        # Todo: Implement Properly
-        # if hasattr(runtime_type, 'is_type_of') and not runtime_type.is_type_of(result):
-        # pass
+        if hasattr(runtime_type, 'is_type_of') and not runtime_type.is_type_of(result, info):
+            raise GraphQLError(
+                u'Expected value of type "{}" but got {}.'.format(return_type, result),
+                field_asts
+            )
 
         # Collect sub-fields to execute to complete this value.
         subfield_asts = {}

graphql/core/type/definition.py

@@ -138,9 +138,13 @@ def get_fields(self):
     def get_interfaces(self):
         return self._interfaces
 
-    def is_type_of(self, value):
+    def is_type_of(self, value, info):
         if self._is_type_of:
-            return self._is_type_of(value)
+            return self._is_type_of(value, info)
+
+        # If we don't have a is_type_of function defined, we will default to
+        # passing the check always.
+        return True
 
 
 def define_field_map(fields):
@@ -218,16 +222,16 @@ def is_possible_type(self, type):
             )
         return type.name in self._possible_type_names
 
-    def resolve_type(self, value):
+    def resolve_type(self, value, info):
         if self._resolver:
             return self._resolver(value)
-        return get_type_of(value, self)
+        return get_type_of(value, info, self)
 
 
-def get_type_of(value, abstract_type):
+def get_type_of(value, info, abstract_type):
     possible_types = abstract_type.get_possible_types()
     for type in possible_types:
-        is_type_of = type.is_type_of(value)
+        is_type_of = type.is_type_of(value, info)
         if is_type_of is None:
             raise Error(
                 'Non-Object Type {} does not implement resolve_type and '
@@ -287,10 +291,10 @@ def is_possible_type(self, type):
             )
         return type.name in self._possible_type_names
 
-    def resolve_type(self, value):
+    def resolve_type(self, value, info):
         if self._resolve_type:
             return self._resolve_type(value)
-        return get_type_of(value, self)
+        return get_type_of(value, info, self)
 
 
 class GraphQLEnumType(GraphQLType):

tests/core_execution/test_union_interface.py

@@ -42,7 +42,7 @@ def __init__(self, name, pets, friends):
         'name': GraphQLField(GraphQLString),
         'barks': GraphQLField(GraphQLBoolean),
     },
-    is_type_of=lambda value: isinstance(value, Dog)
+    is_type_of=lambda value, info: isinstance(value, Dog)
 )
 
 CatType = GraphQLObjectType(
@@ -52,7 +52,7 @@ def __init__(self, name, pets, friends):
         'name': GraphQLField(GraphQLString),
         'meows': GraphQLField(GraphQLBoolean),
     },
-    is_type_of=lambda value: isinstance(value, Cat)
+    is_type_of=lambda value, info: isinstance(value, Cat)
 )
 
 
@@ -73,7 +73,7 @@ def resolve_pet_type(value):
         'pets': GraphQLField(GraphQLList(PetType)),
         'friends': GraphQLField(GraphQLList(NamedType)),
     },
-    is_type_of=lambda value: isinstance(value, Person)
+    is_type_of=lambda value, info: isinstance(value, Person)
 )
 
 schema = GraphQLSchema(PersonType)