Improved default_value

Author: syrusakbary

graphql/execution/values.py

@@ -81,7 +81,7 @@ def get_argument_values(arg_defs, arg_asts, variables=None):
         arg_type = arg_def.type
         value_ast = arg_ast_map.get(name)
         if name not in arg_ast_map:
-            if arg_def.default_value is not Undefined:
+            if arg_def.default_value is not None:
                 result[arg_def.out_name or name] = arg_def.default_value
                 continue
             elif isinstance(arg_type, GraphQLNonNull):
@@ -94,7 +94,7 @@ def get_argument_values(arg_defs, arg_asts, variables=None):
             variable_value = variables.get(variable_name, Undefined)
             if variables and variable_name in variables:
                 result[arg_def.out_name or name] = variable_value
-            elif arg_def.default_value is not Undefined:
+            elif arg_def.default_value is not None:
                 result[arg_def.out_name or name] = arg_def.default_value
             elif isinstance(arg_type, GraphQLNonNull):
                 raise GraphQLError('Argument "{name}" of required type {arg_type}" provided the variable "${variable_name}" which was not provided'.format(
@@ -113,7 +113,7 @@ def get_argument_values(arg_defs, arg_asts, variables=None):
                 variables
             )
             if value is Undefined:
-                if arg_def.default_value is not Undefined:
+                if arg_def.default_value is not None:
                     value = arg_def.default_value
                     result[arg_def.out_name or name] = value
             else:
@@ -150,7 +150,7 @@ def coerce_value(type, value):
         obj = {}
         for field_name, field in fields.items():
             if field_name not in value:
-                if field.default_value is not Undefined:
+                if field.default_value is not None:
                     field_value = field.default_value
                     obj[field.out_name or field_name] = field_value
             else:

graphql/type/definition.py

@@ -266,7 +266,7 @@ def __hash__(self):
 class GraphQLArgument(object):
     __slots__ = 'type', 'default_value', 'description', 'out_name'
 
-    def __init__(self, type, default_value=Undefined, description=None, out_name=None):
+    def __init__(self, type, default_value=None, description=None, out_name=None):
         self.type = type
         self.default_value = default_value
         self.description = description
@@ -545,7 +545,7 @@ def _define_field_map(self):
 class GraphQLInputObjectField(object):
     __slots__ = 'type', 'default_value', 'description', 'out_name'
 
-    def __init__(self, type, default_value=Undefined, description=None, out_name=None):
+    def __init__(self, type, default_value=None, description=None, out_name=None):
         self.type = type
         self.default_value = default_value
         self.description = description

graphql/type/introspection.py

@@ -2,7 +2,7 @@
 
 from ..language.printer import print_ast
 from ..utils.ast_from_value import ast_from_value
-from .definition import (Undefined, GraphQLArgument, GraphQLEnumType, GraphQLEnumValue,
+from .definition import (GraphQLArgument, GraphQLEnumType, GraphQLEnumValue,
                          GraphQLField, GraphQLInputObjectType,
                          GraphQLInterfaceType, GraphQLList, GraphQLNonNull,
                          GraphQLObjectType, GraphQLScalarType,
@@ -345,7 +345,7 @@ def input_fields(type, *_):
         ('defaultValue', GraphQLField(
             type=GraphQLString,
             resolver=lambda input_val, *_:
-            None if input_val.default_value is Undefined
+            None if input_val.default_value is None
             else print_ast(ast_from_value(input_val.default_value, input_val))
         ))
     ]))

graphql/utils/value_from_ast.py

@@ -56,7 +56,7 @@ def value_from_ast(value_ast, type, variables=None):
             field_value = value_from_ast(
                 field_value_ast, field.type, variables
             )
-            if field_value is Undefined:
+            if field_value is Undefined and field.default_value is not None:
                 field_value = field.default_value
 
             if field_value is not Undefined: