Add skip and include directive in introspection schema

Author: leszekhanusz

gql/client.py

@@ -7,7 +7,6 @@
     ExecutionResult,
     GraphQLSchema,
     build_ast_schema,
-    build_client_schema,
     get_introspection_query,
     parse,
     validate,
@@ -17,6 +16,7 @@
 from .transport.exceptions import TransportQueryError
 from .transport.local_schema import LocalSchemaTransport
 from .transport.transport import Transport
+from .utilities import build_client_schema
 from .utilities import parse_result as parse_result_fn
 from .utilities import serialize_variable_values
 

gql/utilities/__init__.py

@@ -1,10 +1,12 @@
+from .build_client_schema import build_client_schema
 from .get_introspection_query_ast import get_introspection_query_ast
 from .parse_result import parse_result
 from .serialize_variable_values import serialize_value, serialize_variable_values
 from .update_schema_enum import update_schema_enum
 from .update_schema_scalars import update_schema_scalar, update_schema_scalars
 
 __all__ = [
+    "build_client_schema",
     "parse_result",
     "get_introspection_query_ast",
     "serialize_variable_values",

gql/utilities/build_client_schema.py

@@ -0,0 +1,73 @@
+from typing import Dict
+
+from graphql import GraphQLSchema
+from graphql import build_client_schema as build_client_schema_orig
+
+__all__ = ["build_client_schema"]
+
+
+INCLUDE_DIRECTIVE_JSON = {
+    "name": "include",
+    "description": (
+        "Directs the executor to include this field or fragment "
+        "only when the `if` argument is true."
+    ),
+    "locations": ["FIELD", "FRAGMENT_SPREAD", "INLINE_FRAGMENT"],
+    "args": [
+        {
+            "name": "if",
+            "description": "Included when true.",
+            "type": {
+                "kind": "NON_NULL",
+                "name": "None",
+                "ofType": {"kind": "SCALAR", "name": "Boolean", "ofType": "None"},
+            },
+            "defaultValue": "None",
+        }
+    ],
+}
+
+SKIP_DIRECTIVE_JSON = {
+    "name": "skip",
+    "description": (
+        "Directs the executor to skip this field or fragment "
+        "when the `if` argument is true."
+    ),
+    "locations": ["FIELD", "FRAGMENT_SPREAD", "INLINE_FRAGMENT"],
+    "args": [
+        {
+            "name": "if",
+            "description": "Skipped when true.",
+            "type": {
+                "kind": "NON_NULL",
+                "name": "None",
+                "ofType": {"kind": "SCALAR", "name": "Boolean", "ofType": "None"},
+            },
+            "defaultValue": "None",
+        }
+    ],
+}
+
+
+def build_client_schema(introspection: Dict) -> GraphQLSchema:
+    """This is an alternative to the graphql-core function
+    :code:`build_client_schema` but with default include and skip directives
+    added to the schema to fix
+    `issue #278 <https://github.com/graphql-python/gql/issues/278>`_
+
+    .. warning::
+        This function will be removed once the issue
+        `graphql-js#3419 <https://github.com/graphql/graphql-js/issues/3419>`_
+        has been fixed and ported to graphql-core so don't use it
+        outside gql.
+    """
+
+    directives = introspection["__schema"]["directives"]
+
+    if not any(directive["name"] == "skip" for directive in directives):
+        directives.append(SKIP_DIRECTIVE_JSON)
+
+    if not any(directive["name"] == "include" for directive in directives):
+        directives.append(INCLUDE_DIRECTIVE_JSON)
+
+    return build_client_schema_orig(introspection, assume_valid=False)

tests/starwars/test_validation.py

@@ -60,7 +60,24 @@ def introspection_schema():
     return Client(introspection=StarWarsIntrospection)
 
 
-@pytest.fixture(params=["local_schema", "typedef_schema", "introspection_schema"])
+@pytest.fixture
+def introspection_schema_no_directives():
+    introspection = StarWarsIntrospection
+
+    # Simulate an empty dictionary for directives
+    introspection["__schema"]["directives"] = []
+
+    return Client(introspection=introspection)
+
+
+@pytest.fixture(
+    params=[
+        "local_schema",
+        "typedef_schema",
+        "introspection_schema",
+        "introspection_schema_no_directives",
+    ]
+)
 def client(request):
     return request.getfixturevalue(request.param)
 
@@ -187,3 +204,32 @@ def test_allows_object_fields_in_inline_fragments(client):
         }
     """
     assert not validation_errors(client, query)
+
+
+def test_include_directive(client):
+    query = """
+        query fetchHero($with_friends: Boolean!) {
+          hero {
+            name
+            friends @include(if: $with_friends) {
+                name
+            }
+          }
+        }
+    """
+    assert not validation_errors(client, query)
+
+
+def test_skip_directive(client):
+    query = """
+        query fetchHero($without_friends: Boolean!) {
+          hero {
+            name
+            friends @skip(if: $without_friends) {
+                name
+            }
+          }
+        }
+    """
+    print(StarWarsIntrospection)
+    assert not validation_errors(client, query)