fix(printer): Fix printer ignoring input arguments using snake_case

RELEASE.md

@@ -0,0 +1,65 @@
+Release type: patch
+
+This release fix an issue where directives with input types using snake_case
+would not be printed in the schema.
+
+For example, the following:
+
+```python
+@strawberry.input
+class FooInput:
+    hello: str
+    hello_world: str
+
+
+@strawberry.schema_directive(locations=[Location.FIELD_DEFINITION])
+class FooDirective:
+    input: FooInput
+
+
+@strawberry.type
+class Query:
+    @strawberry.field(
+        directives=[
+            FooDirective(input=FooInput(hello="hello", hello_world="hello world")),
+        ]
+    )
+    def foo(self, info) -> str: ...
+```
+
+Would previously print as:
+
+```graphql
+directive @fooDirective(
+  input: FooInput!
+  optionalInput: FooInput
+) on FIELD_DEFINITION
+
+type Query {
+  foo: String! @fooDirective(input: { hello: "hello" })
+}
+
+input FooInput {
+  hello: String!
+  hello_world: String!
+}
+```
+
+Now it will be correctly printed as:
+
+```graphql
+directive @fooDirective(
+  input: FooInput!
+  optionalInput: FooInput
+) on FIELD_DEFINITION
+
+type Query {
+  foo: String!
+    @fooDirective(input: { hello: "hello", helloWorld: "hello world" })
+}
+
+input FooInput {
+  hello: String!
+  hello_world: String!
+}
+```

strawberry/printer/printer.py

@@ -5,6 +5,7 @@
 from typing import (
     TYPE_CHECKING,
     Any,
+    Callable,
     Optional,
     TypeVar,
     Union,
@@ -68,40 +69,70 @@ class PrintExtras:
 
 
 @overload
-def _serialize_dataclasses(value: dict[_T, object]) -> dict[_T, object]: ...
+def _serialize_dataclasses(
+    value: dict[_T, object],
+    *,
+    name_converter: Callable[[str], str] | None = None,
+) -> dict[_T, object]: ...
 
 
 @overload
 def _serialize_dataclasses(
     value: Union[list[object], tuple[object]],
+    *,
+    name_converter: Callable[[str], str] | None = None,
 ) -> list[object]: ...
 
 
 @overload
-def _serialize_dataclasses(value: object) -> object: ...
+def _serialize_dataclasses(
+    value: object,
+    *,
+    name_converter: Callable[[str], str] | None = None,
+) -> object: ...
 
 
-def _serialize_dataclasses(value):
+def _serialize_dataclasses(
+    value,
+    *,
+    name_converter: Callable[[str], str] | None = None,
+):
+    if name_converter is None:
+        name_converter = lambda x: x  # noqa: E731
+
     if dataclasses.is_dataclass(value):
-        return {k: v for k, v in dataclasses.asdict(value).items() if v is not UNSET}  # type: ignore
+        return {
+            name_converter(k): v
+            for k, v in dataclasses.asdict(value).items()  # type: ignore
+            if v is not UNSET
+        }
     if isinstance(value, (list, tuple)):
         return [_serialize_dataclasses(v) for v in value]
     if isinstance(value, dict):
-        return {k: _serialize_dataclasses(v) for k, v in value.items()}
+        return {name_converter(k): _serialize_dataclasses(v) for k, v in value.items()}
 
     return value
 
 
 def print_schema_directive_params(
-    directive: GraphQLDirective, values: dict[str, Any]
+    directive: GraphQLDirective,
+    values: dict[str, Any],
+    *,
+    schema: BaseSchema,
 ) -> str:
     params = []
     for name, arg in directive.args.items():
         value = values.get(name, arg.default_value)
         if value is UNSET:
             value = None
         else:
-            ast = ast_from_value(_serialize_dataclasses(value), arg.type)
+            ast = ast_from_value(
+                _serialize_dataclasses(
+                    value,
+                    name_converter=schema.config.name_converter.apply_naming_config,
+                ),
+                arg.type,
+            )
             value = ast and f"{name}: {print_ast(ast)}"
 
         if value:
@@ -129,6 +160,7 @@ def print_schema_directive(
             )
             for f in strawberry_directive.fields
         },
+        schema=schema,
     )
 
     printed_directive = print_directive(gql_directive, schema=schema)

tests/test_printer/test_schema_directives.py

@@ -749,3 +749,43 @@ def foo(self, info) -> str: ...
     schema = strawberry.Schema(query=Query)
 
     assert print_schema(schema) == textwrap.dedent(expected_output).strip()
+
+
+def test_print_directive_with_snake_case_arguments():
+    @strawberry.input
+    class FooInput:
+        hello: str
+        hello_world: str
+
+    @strawberry.schema_directive(locations=[Location.FIELD_DEFINITION])
+    class FooDirective:
+        input: FooInput
+        optional_input: Optional[FooInput] = strawberry.UNSET
+
+    @strawberry.type
+    class Query:
+        @strawberry.field(
+            directives=[
+                FooDirective(input=FooInput(hello="hello", hello_world="hello world"))
+            ]
+        )
+        def foo(self, info) -> str: ...
+
+    schema = strawberry.Schema(query=Query)
+
+    expected_output = """
+    directive @fooDirective(input: FooInput!, optionalInput: FooInput) on FIELD_DEFINITION
+
+    type Query {
+      foo: String! @fooDirective(input: {hello: "hello", helloWorld: "hello world"})
+    }
+
+    input FooInput {
+      hello: String!
+      helloWorld: String!
+    }
+    """
+
+    schema = strawberry.Schema(query=Query)
+
+    assert print_schema(schema) == textwrap.dedent(expected_output).strip()