print_schema: correctly print empty description

Replicates graphql/graphql-js@3cf08e6

Author: Cito

src/graphql/utilities/extend_schema.py

@@ -245,6 +245,13 @@ def extend_schema_args(
 
         # Then produce and return the kwargs for a Schema with these types.
         get_operation = operation_types.get
+        description = (
+            schema_def.description.value
+            if schema_def and schema_def.description
+            else None
+        )
+        if description is None:
+            description = schema_kwargs["description"]
         return GraphQLSchemaKwargs(
             query=get_operation(OperationType.QUERY),  # type: ignore
             mutation=get_operation(OperationType.MUTATION),  # type: ignore
@@ -255,12 +262,7 @@ def extend_schema_args(
                 for directive in schema_kwargs["directives"]
             )
             + tuple(self.build_directive(directive) for directive in directive_defs),
-            description=(
-                schema_def.description.value
-                if schema_def and schema_def.description
-                else None
-            )
-            or schema_kwargs["description"],
+            description=description,
             extensions=schema_kwargs["extensions"],
             ast_node=schema_def or schema_kwargs["ast_node"],
             extension_ast_nodes=schema_kwargs["extension_ast_nodes"]

src/graphql/utilities/print_schema.py

@@ -83,7 +83,7 @@ def print_schema_definition(schema: GraphQLSchema) -> str | None:
 
     # Only print a schema definition if there is a description or if it should
     # not be omitted because of having default type names.
-    if schema.description or not has_default_root_operation_types(schema):
+    if not (schema.description is None and has_default_root_operation_types(schema)):
         return (
             print_description(schema)
             + "schema {\n"
@@ -235,7 +235,7 @@ def print_args(args: dict[str, GraphQLArgument], indentation: str = "") -> str:
         return ""
 
     # If every arg does not have a description, print them on one line.
-    if not any(arg.description for arg in args.values()):
+    if all(arg.description is None for arg in args.values()):
         return (
             "("
             + ", ".join(print_input_value(name, arg) for name, arg in args.items())

tests/utilities/test_print_schema.py

@@ -8,6 +8,7 @@
     GraphQLBoolean,
     GraphQLDirective,
     GraphQLEnumType,
+    GraphQLEnumValue,
     GraphQLField,
     GraphQLFloat,
     GraphQLInputField,
@@ -602,13 +603,108 @@ def prints_custom_directives():
         )
 
     def prints_an_empty_description():
-        schema = build_single_field_schema(GraphQLField(GraphQLString, description=""))
+        args = {
+            "someArg": GraphQLArgument(GraphQLString, description=""),
+            "anotherArg": GraphQLArgument(GraphQLString, description=""),
+        }
+        fields = {
+            "someField": GraphQLField(GraphQLString, args, description=""),
+            "anotherField": GraphQLField(GraphQLString, args, description=""),
+        }
+        query_type = GraphQLObjectType("Query", fields, description="")
+        scalar_type = GraphQLScalarType("SomeScalar", description="")
+        interface_type = GraphQLInterfaceType("SomeInterface", fields, description="")
+        union_type = GraphQLUnionType("SomeUnion", [query_type], description="")
+        enum_type = GraphQLEnumType(
+            "SomeEnum",
+            {
+                "SOME_VALUE": GraphQLEnumValue("Some Value", description=""),
+                "ANOTHER_VALUE": GraphQLEnumValue("Another Value", description=""),
+            },
+            description="",
+        )
+        some_directive = GraphQLDirective(
+            "someDirective", [DirectiveLocation.QUERY], args, description=""
+        )
+
+        schema = GraphQLSchema(
+            query_type,
+            types=[scalar_type, interface_type, union_type, enum_type],
+            directives=[some_directive],
+            description="",
+        )
 
         assert expect_printed_schema(schema) == dedent(
             '''
+            """"""
+            schema {
+              query: Query
+            }
+
+            """"""
+            directive @someDirective(
+              """"""
+              someArg: String
+
+              """"""
+              anotherArg: String
+            ) on QUERY
+
+            """"""
+            scalar SomeScalar
+
+            """"""
+            interface SomeInterface {
+              """"""
+              someField(
+                """"""
+                someArg: String
+
+                """"""
+                anotherArg: String
+              ): String
+
+              """"""
+              anotherField(
+                """"""
+                someArg: String
+
+                """"""
+                anotherArg: String
+              ): String
+            }
+
+            """"""
+            union SomeUnion = Query
+
+            """"""
             type Query {
               """"""
-              singleField: String
+              someField(
+                """"""
+                someArg: String
+
+                """"""
+                anotherArg: String
+              ): String
+
+              """"""
+              anotherField(
+                """"""
+                someArg: String
+
+                """"""
+                anotherArg: String
+              ): String
+            }
+
+            """"""
+            enum SomeEnum {
+              """"""
+              SOME_VALUE
+
+              """"""
+              ANOTHER_VALUE
             }
             '''
         )