build_client_schema: improve coverage

Also fix an incompatibility with GraphQL.js.

Replicates graphql/graphql-js@7eb38ea

Author: Cito

README.md

@@ -13,7 +13,7 @@ a query language for APIs created by Facebook.
 [![Code Style](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/ambv/black)
 
 The current version 1.0.5 of GraphQL-core-next is up-to-date with GraphQL.js version
-14.3.1. All parts of the API are covered by an extensive test suite of currently 1823
+14.3.1. All parts of the API are covered by an extensive test suite of currently 1825
 unit tests.
 
 

graphql/type/directives.py

@@ -1,4 +1,4 @@
-from typing import Any, Dict, Optional, Sequence, cast
+from typing import Any, Dict, List, Optional, Sequence, cast
 
 from ..language import ast, DirectiveLocation
 from ..pyutils import inspect, FrozenList
@@ -177,7 +177,7 @@ def assert_directive(directive: Any) -> GraphQLDirective:
 )
 
 
-specified_directives = FrozenList(
+specified_directives: List[GraphQLDirective] = FrozenList(
     [GraphQLIncludeDirective, GraphQLSkipDirective, GraphQLDeprecatedDirective]
 )
 specified_directives.__doc__ = """The full list of specified directives."""

graphql/type/scalars.py

@@ -1,5 +1,5 @@
 from math import isfinite
-from typing import Any
+from typing import Any, Dict
 
 from ..error import INVALID
 from ..pyutils import inspect, is_finite, is_integer, FrozenDict
@@ -241,7 +241,7 @@ def parse_id_literal(ast, _variables=None):
 )
 
 
-specified_scalar_types = FrozenDict(
+specified_scalar_types: Dict[str, GraphQLScalarType] = FrozenDict(
     {
         type_.name: type_
         for type_ in (

graphql/type/schema.py

@@ -124,7 +124,10 @@ def __init__(
         self.mutation_type = mutation
         self.subscription_type = subscription
         # Provide specified directives (e.g. @include and @skip) by default
-        self.directives = list(directives or specified_directives)
+        self.directives = cast(
+            List[GraphQLDirective],
+            specified_directives if directives is None else directives,
+        )
         self.ast_node = ast_node
         self.extension_ast_nodes = (
             cast(Tuple[ast.SchemaExtensionNode], tuple(extension_ast_nodes))

tests/utilities/test_build_client_schema.py

@@ -63,6 +63,23 @@ def builds_a_simple_schema():
 
         assert cycle_introspection(sdl) == sdl
 
+    def builds_a_schema_without_the_query_type():
+        sdl = dedent(
+            """
+            type Query {
+              foo: String
+            }
+            """
+        )
+
+        schema = build_schema(sdl)
+        introspection = introspection_from_schema(schema)
+        del introspection["__schema"]["queryType"]
+
+        client_schema = build_client_schema(introspection)
+        assert client_schema.query_type is None
+        assert print_schema(client_schema) == sdl
+
     def builds_a_simple_schema_with_all_operation_types():
         sdl = dedent(
             '''
@@ -411,6 +428,25 @@ def builds_a_schema_with_custom_directives():
 
         assert cycle_introspection(sdl) == sdl
 
+    def builds_a_schema_without_directives():
+        sdl = dedent(
+            """
+            type Query {
+              foo: String
+            }
+            """
+        )
+
+        schema = build_schema(sdl)
+        introspection = introspection_from_schema(schema)
+        del introspection["__schema"]["directives"]
+
+        client_schema = build_client_schema(introspection)
+
+        assert schema.directives
+        assert client_schema.directives == []
+        assert print_schema(client_schema) == sdl
+
     def builds_a_schema_aware_of_deprecation():
         sdl = dedent(
             '''