classgen: produce typedDict instead of dataclass

pkgs/classgen/main.py

@@ -148,8 +148,7 @@ def field_def_from_default_value(
             default_factory="dict",
             type_appendix=" | dict[str,Any]",
         )
-    if default_value == "‹name›":
-        return None
+
     # Primitive types
     if isinstance(default_value, str):
         return finalize_field(
@@ -176,23 +175,15 @@ def get_field_def(
     default_factory: str | None = None,
     type_appendix: str = "",
 ) -> str:
-    sorted_field_types = sorted(field_types)
-    serialised_types = " | ".join(sorted_field_types) + type_appendix
-    if not default and not default_factory and not field_meta:
-        return f"{field_name}: {serialised_types}"
-    field_init = "field("
+    if "None" in field_types or default or default_factory:
+        if "None" in field_types:
+            field_types.remove("None")
+        serialised_types = " | ".join(field_types) + type_appendix
+        serialised_types = f"NotRequired[{serialised_types}]"
+    else:
+        serialised_types = " | ".join(field_types) + type_appendix
 
-    init_args = []
-    if default:
-        init_args.append(f"default = {default}")
-    if default_factory:
-        init_args.append(f"default_factory = {default_factory}")
-    if field_meta:
-        init_args.append(f"metadata = {field_meta}")
-
-    field_init += ", ".join(init_args) + ")"
-
-    return f"{field_name}: {serialised_types} = {field_init}"
+    return f"{field_name}: {serialised_types}"
 
 
 # Recursive function to generate dataclasses from JSON schema
@@ -281,6 +272,9 @@ def generate_dataclass(schema: dict[str, Any], class_name: str = root_class) ->
         finalize_field = partial(get_field_def, field_name, field_meta)
 
         if "default" in prop_info or field_name not in prop_info.get("required", []):
+            if prop_info.get("type") == "object":
+                prop_info.update({"default": {}})
+
             if "default" in prop_info:
                 default_value = prop_info.get("default")
                 field_def = field_def_from_default_value(
@@ -327,11 +321,11 @@ def generate_dataclass(schema: dict[str, Any], class_name: str = root_class) ->
     fields_str = "\n    ".join(required_fields + fields_with_default)
     nested_classes_str = "\n\n".join(nested_classes)
 
-    class_def = f"@dataclass\nclass {class_name}:\n"
+    class_def = f"\nclass {class_name}(TypedDict):\n"
     if not required_fields + fields_with_default:
         class_def += "    pass"
     else:
-        class_def += f"    {fields_str}\n"
+        class_def += f"    {fields_str}"
 
     return f"{nested_classes_str}\n\n{class_def}" if nested_classes_str else class_def
 
@@ -356,8 +350,7 @@ def run_gen(args: argparse.Namespace) -> None:
 # ruff: noqa: N806
 # ruff: noqa: F401
 # fmt: off
-from dataclasses import dataclass, field
-from typing import Any, Literal\n\n
+from typing import Any, Literal, TypedDict, NotRequired\n
 """
         )
         f.write(dataclass_code)