Preserve declaration order on dump

CHANGELOG.md

@@ -1,3 +1,8 @@
+## unreleased
+
+* [Preserve declaration order](https://github.com/anna-money/marshmallow-recipe/pull/164)
+
+
 ## v0.0.41(2024-11-01)
 
 * [Int enum support](https://github.com/anna-money/marshmallow-recipe/pull/161)

marshmallow_recipe/bake.py

@@ -44,6 +44,7 @@ class _SchemaTypeKey:
 
 _T = TypeVar("_T")
 _MARSHMALLOW_VERSION_MAJOR = int(m.__version__.split(".")[0])
+
 _schema_types: dict[_SchemaTypeKey, type[m.Schema]] = {}
 
 
@@ -281,6 +282,10 @@ class _Schema(m.Schema):
             class Meta:  # type: ignore
                 unknown = m.EXCLUDE  # type: ignore
 
+            @property
+            def set_class(self) -> type:
+                return m.schema.OrderedSet  # type: ignore
+
             @m.post_dump
             def remove_none_values(self, data: dict[str, Any], **_: Any) -> dict[str, Any]:
                 if none_value_handling == NoneValueHandling.IGNORE:
@@ -304,6 +309,10 @@ def pre_load(self, data: dict[str, Any], **_: Any) -> Any:
 
     def _get_base_schema(cls: type, none_value_handling: NoneValueHandling) -> type[m.Schema]:
         class _Schema(m.Schema):  # type: ignore
+            @property
+            def set_class(self) -> type:
+                return m.schema.OrderedSet  # type: ignore
+
             @m.post_dump  # type: ignore
             def remove_none_values(self, data: dict[str, Any]) -> dict[str, Any]:
                 if none_value_handling == NoneValueHandling.IGNORE:

tests/test_order.py

@@ -0,0 +1,12 @@
+import dataclasses
+
+import marshmallow_recipe as mr
+
+
+def test_order():
+    @dataclasses.dataclass
+    class A:
+        a: int
+        b: int
+
+    assert [name for name in mr.dump(A(a=1, b=2))] == ["a", "b"]