[MOD-3431] Add default value field to ClassParameterSpec

modal/_utils/function_utils.py

@@ -4,7 +4,7 @@
 import os
 from enum import Enum
 from pathlib import Path, PurePosixPath
-from typing import Any, AsyncIterator, Callable, Dict, List, Literal, Optional, Type
+from typing import Any, AsyncIterator, Callable, Dict, List, Literal, Optional, Tuple, Type
 
 from grpclib import GRPCError
 from grpclib.exceptions import StreamTerminatedError
@@ -28,6 +28,12 @@ class FunctionInfoType(Enum):
     NOTEBOOK = "notebook"
 
 
+CLASS_PARAM_TYPE_MAP: Dict[Type, Tuple["api_pb2.ParameterType.ValueType", str]] = {
+    str: (api_pb2.PARAM_TYPE_STRING, "string_default"),
+    int: (api_pb2.PARAM_TYPE_INT, "int_default"),
+}
+
+
 class LocalFunctionError(InvalidError):
     """Raised if a function declared in a non-global scope is used in an impermissible way"""
 
@@ -238,13 +244,14 @@ def class_parameter_info(self) -> api_pb2.ClassParameterInfo:
         modal_parameters: List[api_pb2.ClassParameterSpec] = []
         signature = inspect.signature(self.user_cls)
         for param in signature.parameters.values():
-            if param.annotation == str:
-                param_type = api_pb2.PARAM_TYPE_STRING
-            elif param.annotation == int:
-                param_type = api_pb2.PARAM_TYPE_INT
-            else:
+            has_default = param.default is not param.empty
+            if param.annotation not in CLASS_PARAM_TYPE_MAP:
                 raise InvalidError("Strict class parameters need to be explicitly annotated as str or int")
-            modal_parameters.append(api_pb2.ClassParameterSpec(name=param.name, type=param_type))
+            param_type, default_field = CLASS_PARAM_TYPE_MAP[param.annotation]
+            class_param_spec = api_pb2.ClassParameterSpec(name=param.name, has_default=has_default, type=param_type)
+            if has_default:
+                setattr(class_param_spec, default_field, param.default)
+            modal_parameters.append(class_param_spec)
 
         return api_pb2.ClassParameterInfo(
             format=api_pb2.ClassParameterInfo.PARAM_SERIALIZATION_FORMAT_PROTO, schema=modal_parameters

modal_proto/api.proto

@@ -585,6 +585,11 @@ message ClassParameterSet {
 message ClassParameterSpec {
   string name = 1;
   ParameterType type = 2;
+  bool has_default = 3;
+  oneof default_oneof {
+    string string_default = 4;
+    int64 int_default = 5;
+  }
 }
 
 message ClassParameterValue {

test/cls_test.py

@@ -797,7 +797,7 @@ def test_cls_strict_parameters_added_to_definition(client, servicer, monkeypatch
 
     @strict_param_cls_app.cls(serialized=True)
     class StrictParamCls:
-        def __init__(self, x: str, y: int):
+        def __init__(self, x: str, y: int = 20):
             pass
 
     deploy_app(strict_param_cls_app, "my-cls-app", client=client)
@@ -808,8 +808,8 @@ def __init__(self, x: str, y: int):
     assert definition.class_parameter_info == api_pb2.ClassParameterInfo(
         format=api_pb2.ClassParameterInfo.PARAM_SERIALIZATION_FORMAT_PROTO,
         schema=[
-            api_pb2.ClassParameterSpec(name="x", type=api_pb2.PARAM_TYPE_STRING),
-            api_pb2.ClassParameterSpec(name="y", type=api_pb2.PARAM_TYPE_INT),
+            api_pb2.ClassParameterSpec(name="x", type=api_pb2.PARAM_TYPE_STRING, has_default=False),
+            api_pb2.ClassParameterSpec(name="y", type=api_pb2.PARAM_TYPE_INT, has_default=True, int_default=20),
         ],
     )