Fix issue where input value not being provided would raise a KeyError.

Closes #22.

Author: jhgg

graphql/core/execution/values.py

@@ -128,7 +128,7 @@ def coerce_value(type, value):
         fields = type.get_fields()
         obj = {}
         for field_name, field in fields.items():
-            field_value = coerce_value(field.type, value[field_name])
+            field_value = coerce_value(field.type, value.get(field_name))
             if field_value is None:
                 field_value = field.default_value
 

graphql/core/utils/value_from_ast.py

@@ -55,7 +55,8 @@ def value_from_ast(value_ast, type, variables=None):
             if field_value is None:
                 field_value = field.default_value
 
-            obj[field_name] = field_value
+            if field_value is not None:
+                obj[field_name] = field_value
 
         return obj