propagate explicit null args to resolvers

graphql/execution/tests/test_execute_schema.py

@@ -1,5 +1,7 @@
 # type: ignore
 
+from itertools import starmap, repeat
+from typing import Union
 from graphql.execution import execute
 from graphql.language.parser import parse
 from graphql.type import (
@@ -51,36 +53,44 @@ def test_executes_using_a_schema():
  {
  "id": GraphQLField(GraphQLNonNull(GraphQLString)),
  "isPublished": GraphQLField(GraphQLBoolean),
+ "topic": GraphQLField(GraphQLString),
  "author": GraphQLField(BlogAuthor),
  "title": GraphQLField(GraphQLString),
  "body": GraphQLField(GraphQLString),
  "keywords": GraphQLField(GraphQLList(GraphQLString)),
  },
  )
 
+ def _resolve_article(obj, info, id, topic):
+ return Article(id, topic)
+
+ def _resolve_feed(*_):
+ return list(starmap(Article, zip(range(1, 10 + 1), repeat("food"))))
+
  BlogQuery = GraphQLObjectType(
  "Query",
  {
  "article": GraphQLField(
  BlogArticle,
- args={"id": GraphQLArgument(GraphQLID)},
- resolver=lambda obj, info, **args: Article(args["id"]),
- ),
- "feed": GraphQLField(
- GraphQLList(BlogArticle),
- resolver=lambda *_: map(Article, range(1, 10 + 1)),
+ args={
+ "id": GraphQLArgument(GraphQLID),
+ "topic": GraphQLArgument(GraphQLNonNull(GraphQLString)),
+ },
+ resolver=_resolve_article,
  ),
+ "feed": GraphQLField(GraphQLList(BlogArticle), resolver=_resolve_feed),
  },
  )
 
  BlogSchema = GraphQLSchema(BlogQuery)
 
  class Article(object):
- def __init__(self, id):
- # type: (int) -> None
+ def __init__(self, id, topic):
+ # type: (int, Union[str, None]) -> None
  self.id = id
  self.isPublished = True
  self.author = Author()
+ self.topic = "My topic is {}".format(topic or "null")
  self.title = "My Article {}".format(id)
  self.body = "This is a post"
  self.hidden = "This data is not exposed in the schema"
@@ -97,7 +107,7 @@ def pic(self, width, height):
  @property
  def recentArticle(self):
  # type: () -> Article
- return Article(1)
+ return Article(1, "food")
 
  class Pic(object):
  def __init__(self, uid, width, height):
@@ -112,7 +122,7 @@ def __init__(self, uid, width, height):
  id,
  title
  },
- article(id: "1") {
+ article(id: "1", topic: null) {
  ...articleFields,
  author {
  id,
@@ -132,6 +142,7 @@ def __init__(self, uid, width, height):
  fragment articleFields on Article {
  id,
  isPublished,
+ topic,
  title,
  body,
  hidden,
@@ -159,6 +170,7 @@ def __init__(self, uid, width, height):
  "article": {
  "id": "1",
  "isPublished": True,
+ "topic": "My topic is null",
  "title": "My Article 1",
  "body": "This is a post",
  "author": {
@@ -168,6 +180,7 @@ def __init__(self, uid, width, height):
  "recentArticle": {
  "id": "1",
  "isPublished": True,
+ "topic": "My topic is food",
  "title": "My Article 1",
  "body": "This is a post",
  "keywords": ["foo", "bar", "1", "true", None],

graphql/execution/tests/test_mutations.py

@@ -107,7 +107,16 @@ def assert_evaluate_mutations_serially(executor=None):
  },
  fifth: immediatelyChangeTheNumber(newNumber: 5) {
  theNumber
- }
+ },
+ sixth: immediatelyChangeTheNumber(newNumber: null) {
+ theNumber
+ },
+ seventh: immediatelyChangeTheNumber(newNumber: 100) {
+ theNumber
+ },
+ eighth: immediatelyChangeTheNumber(newNumber: null) {
+ theNumber
+ },
  }"""
  ast = parse(doc)
  result = execute(schema, ast, Root(6), operation_name="M", executor=executor)
@@ -118,6 +127,9 @@ def assert_evaluate_mutations_serially(executor=None):
  "third": {"theNumber": 3},
  "fourth": {"theNumber": 4},
  "fifth": {"theNumber": 5},
+ "sixth": {"theNumber": None},
+ "seventh": {"theNumber": 100},
+ "eighth": {"theNumber": None},
  }
 
 

graphql/execution/tests/test_resolve.py

@@ -49,6 +49,27 @@ def _test_schema(test_field):
  )
 
 
+def test_explicit_null_is_passed_to_resolver():
+ def resolver(_, __, maybe_string):
+ return 'maybe_string is "{}"'.format(maybe_string or "null")
+
+ schema = _test_schema(
+ GraphQLField(
+ GraphQLString,
+ args=OrderedDict([("maybe_string", GraphQLArgument(GraphQLString))]),
+ resolver=resolver,
+ )
+ )
+
+ result = graphql(schema, '{ test(maybe_string: "Cool") }')
+ assert not result.errors
+ assert result.data == {"test": 'maybe_string is "Cool"'}
+
+ result = graphql(schema, "{ test(maybe_string: null) }")
+ assert not result.errors
+ assert result.data == {"test": 'maybe_string is "null"'}
+
+
 def test_default_function_accesses_properties():
  # type: () -> None
  schema = _test_schema(GraphQLField(GraphQLString))

graphql/execution/values.py

@@ -134,15 +134,16 @@ def get_argument_values(
  continue
 
  else:
- value = value_from_ast(arg_ast.value, arg_type, variables) # type: ignore
- if value is None:
+ arg_name = arg_def.out_name or name # type: ignore
+ arg_ast_value = arg_ast.value # type: ignore
+ value = value_from_ast(arg_ast_value, arg_type, variables) # type: ignore
+ if value is None and not isinstance(arg_ast_value, ast.NullValue):
  if arg_def.default_value is not Undefined:
- value = arg_def.default_value
- result[arg_def.out_name or name] = value
+ result[arg_name] = arg_def.default_value
+ else:
+ result[arg_name] = None
  else:
- # We use out_name as the output name for the
- # dict if exists
- result[arg_def.out_name or name] = value
+ result[arg_name] = value
 
  return result