Manually print defer and stream directives

Author: patrick91

strawberry/printer/printer.py

@@ -621,6 +621,14 @@ def print_schema(schema: BaseSchema) -> str:
         if (printed_directive := print_directive(directive, schema=schema)) is not None
     ]
 
+    if schema.config.enable_experimental_incremental_execution:
+        directives.append(
+            "directive @defer(if: Boolean, label: String) on FRAGMENT_SPREAD | INLINE_FRAGMENT"
+        )
+        directives.append(
+            "directive @stream(if: Boolean, label: String, initialCount: Int = 0) on FIELD"
+        )
+
     def _name_getter(type_: Any) -> str:
         if hasattr(type_, "name"):
             return type_.name

tests/test_printer/test_defer_stream.py

@@ -0,0 +1,48 @@
+from __future__ import annotations
+
+import textwrap
+
+import strawberry
+from strawberry.schema.config import StrawberryConfig
+from tests.conftest import skip_if_gql_32
+
+pytestmark = skip_if_gql_32("GraphQL 3.3.0 is required for incremental execution")
+
+
+@strawberry.type
+class Query:
+    hello: str
+
+
+def test_does_not_print_defer_and_stream_directives_when_experimental_execution_is_disabled():
+    schema = strawberry.Schema(
+        query=Query,
+        config=StrawberryConfig(enable_experimental_incremental_execution=False),
+    )
+
+    expected_type = """
+    type Query {
+      hello: String!
+    }
+    """
+
+    assert str(schema) == textwrap.dedent(expected_type).strip()
+
+
+def test_prints_defer_and_stream_directives_when_experimental_execution_is_enabled():
+    schema = strawberry.Schema(
+        query=Query,
+        config=StrawberryConfig(enable_experimental_incremental_execution=True),
+    )
+
+    expected_type = """
+    directive @defer(if: Boolean, label: String) on FRAGMENT_SPREAD | INLINE_FRAGMENT
+
+    directive @stream(if: Boolean, label: String, initialCount: Int = 0) on FIELD
+
+    type Query {
+      hello: String!
+    }
+    """
+
+    assert str(schema) == textwrap.dedent(expected_type).strip()