feat: useOptionals=all

src/betterproto/__init__.py

@@ -1439,6 +1439,8 @@ def to_dict(
                 elif field_is_repeated:
                     # Convert each item.
                     cls = self._betterproto.cls_by_field[field_name]
+                    if not value:
+                        value = []
                     if cls == datetime:
                         value = [_Timestamp.timestamp_to_json(i) for i in value]
                     elif cls == timedelta:

src/betterproto/plugin/models.py

@@ -29,14 +29,20 @@
 reference to `A` to `B`'s `fields` attribute.
 """
 
-
 import builtins
 import re
 import textwrap
 from dataclasses import (
     dataclass,
     field,
 )
+
+
+try:
+    from typing import Literal
+except ImportError:
+    from typing_extensions import Literal
+
 from typing import (
     Dict,
     Iterable,
@@ -250,6 +256,7 @@ class OutputTemplate:
     services: List["ServiceCompiler"] = field(default_factory=list)
     imports_type_checking_only: Set[str] = field(default_factory=set)
     pydantic_dataclasses: bool = False
+    use_optionals: Optional[Literal["all"]] = None
     output: bool = True
 
     @property
@@ -483,7 +490,7 @@ def repeated(self) -> bool:
 
     @property
     def optional(self) -> bool:
-        return self.proto_obj.proto3_optional
+        return self.proto_obj.proto3_optional or self.output_file.use_optionals == "all"
 
     @property
     def mutable(self) -> bool:

src/betterproto/plugin/parser.py

@@ -98,6 +98,9 @@ def generate_code(request: CodeGeneratorRequest) -> CodeGeneratorResponse:
                 output_package_name
             ].pydantic_dataclasses = True
 
+        if "useOptionals=all" in plugin_options:
+            request_data.output_packages[output_package_name].use_optionals = "all"
+
     # Read Messages and Enums
     # We need to read Messages before Services in so that we can
     # get the references to input/output messages for each service