betterproto: support Struct and Value (#551)

* betterproto: support `Struct` and `Value`

Signed-off-by: William Woodruff <william@trailofbits.com>

* betterproto: handle struct in to_dict as well

Signed-off-by: William Woodruff <william@trailofbits.com>

* tests: add Struct roundtrip tests

Signed-off-by: William Woodruff <william@trailofbits.com>

* specialize from_dict and to_dict on Struct

...rather than special-casing in the Message ABC.

Signed-off-by: William Woodruff <william@trailofbits.com>

* betterproto: `poe format`

Signed-off-by: William Woodruff <william@trailofbits.com>

* Update src/betterproto/__init__.py

Co-authored-by: James Hilton-Balfe <gobot1234yt@gmail.com>

* remove future annotations

Signed-off-by: William Woodruff <william@trailofbits.com>

* replace type[...] with typing.T

Signed-off-by: William Woodruff <william@trailofbits.com>

* quote instead

Signed-off-by: William Woodruff <william@trailofbits.com>

---------

Signed-off-by: William Woodruff <william@trailofbits.com>
Co-authored-by: James Hilton-Balfe <gobot1234yt@gmail.com>

src/betterproto/lib/google/protobuf/__init__.py

@@ -2,14 +2,19 @@
 # sources: google/protobuf/any.proto, google/protobuf/api.proto, google/protobuf/descriptor.proto, google/protobuf/duration.proto, google/protobuf/empty.proto, google/protobuf/field_mask.proto, google/protobuf/source_context.proto, google/protobuf/struct.proto, google/protobuf/timestamp.proto, google/protobuf/type.proto, google/protobuf/wrappers.proto
 # plugin: python-betterproto
 # This file has been @generated
+
 import warnings
 from dataclasses import dataclass
 from typing import (
     Dict,
     List,
+    Mapping,
 )
 
+from typing_extensions import Self
+
 import betterproto
+from betterproto.utils import hybridmethod
 
 
 class Syntax(betterproto.Enum):
@@ -1458,6 +1463,32 @@ class Struct(betterproto.Message):
     )
     """Unordered map of dynamically typed values."""
 
+    @hybridmethod
+    def from_dict(cls: "type[Self]", value: Mapping[str, Any]) -> Self:  # type: ignore
+        self = cls()
+        return self.from_dict(value)
+
+    @from_dict.instancemethod
+    def from_dict(self, value: Mapping[str, Any]) -> Self:
+        fields = {**value}
+        for k in fields:
+            if hasattr(fields[k], "from_dict"):
+                fields[k] = fields[k].from_dict()
+
+        self.fields = fields
+        return self
+
+    def to_dict(
+        self,
+        casing: betterproto.Casing = betterproto.Casing.CAMEL,
+        include_default_values: bool = False,
+    ) -> Dict[str, Any]:
+        output = {**self.fields}
+        for k in self.fields:
+            if hasattr(self.fields[k], "to_dict"):
+                output[k] = self.fields[k].to_dict(casing, include_default_values)
+        return output
+
 
 @dataclass(eq=False, repr=False)
 class Value(betterproto.Message):

tests/test_struct.py

@@ -0,0 +1,24 @@
+import json
+
+from betterproto.lib.google.protobuf import Struct
+
+
+def test_struct_roundtrip():
+    data = {
+        "foo": "bar",
+        "baz": None,
+        "quux": 123,
+        "zap": [1, {"two": 3}, "four"],
+    }
+    data_json = json.dumps(data)
+
+    struct_from_dict = Struct().from_dict(data)
+    assert struct_from_dict.fields == data
+    assert struct_from_dict.to_dict() == data
+    assert struct_from_dict.to_json() == data_json
+
+    struct_from_json = Struct().from_json(data_json)
+    assert struct_from_json.fields == data
+    assert struct_from_json.to_dict() == data
+    assert struct_from_json == struct_from_dict
+    assert struct_from_json.to_json() == data_json