fix: fix use of computed_field setter with field_dependencies (#336)

* fix: fix use of computed_field setter with property_setters

* extend test

* fix error

src/psygnal/_evented_model.py

@@ -32,6 +32,8 @@
     from pydantic import ConfigDict
     from pydantic._internal import _model_construction as pydantic_main
     from pydantic._internal import _utils as utils
+    from pydantic._internal._decorators import PydanticDescriptorProxy
+    from typing_extensions import TypeGuard  # py310
     from typing_extensions import dataclass_transform as dataclass_transform  # py311
 
     from ._signal import SignalInstance
@@ -133,6 +135,15 @@ def _get_fields(cls: pydantic.BaseModel) -> Dict[str, pydantic.fields.FieldInfo]
     def _model_dump(obj: pydantic.BaseModel) -> dict:
         return obj.model_dump()
 
+    def _is_pydantic_descriptor_proxy(obj: Any) -> "TypeGuard[PydanticDescriptorProxy]":
+        if (
+            type(obj).__module__.startswith("pydantic")
+            and type(obj).__name__ == "PydanticDescriptorProxy"
+            and isinstance(getattr(obj, "wrapped", None), property)
+        ):
+            return True
+        return False
+
 else:
 
     @no_type_check
@@ -171,6 +182,9 @@ def _get_fields(cls: type) -> Dict[str, FieldInfo]:
     def _model_dump(obj: pydantic.BaseModel) -> dict:
         return obj.dict()
 
+    def _is_pydantic_descriptor_proxy(obj: Any) -> "TypeGuard[PydanticDescriptorProxy]":
+        return False
+
 
 class ComparisonDelayer:
     """Context that delays before/after comparisons until exit."""
@@ -259,10 +273,14 @@ def __new__(
         # in EventedModel.__setattr__
         cls.__property_setters__ = {}
         if allow_props:
+            # inherit property setters from base classes
             for b in reversed(cls.__bases__):
                 if hasattr(b, "__property_setters__"):
                     cls.__property_setters__.update(b.__property_setters__)
+            # add property setters from this class
             for key, attr in namespace.items():
+                if _is_pydantic_descriptor_proxy(attr):
+                    attr = attr.wrapped
                 if isinstance(attr, property) and attr.fset is not None:
                     cls.__property_setters__[key] = attr
                     recursion = emission_map.get(key, default_strategy)
@@ -335,7 +353,7 @@ class Config:
         for prop, fields in cfg_deps.items():
             if prop not in {*model_fields, *cls.__property_setters__}:
                 raise ValueError(
-                    "Fields with dependencies must be fields or property.setters."
+                    "Fields with dependencies must be fields or property.setters. "
                     f"{prop!r} is not."
                 )
             for field in fields:

tests/test_evented_model.py

@@ -939,3 +939,46 @@ class Config:
     else:
         assert m.events.a._reemission == mode
         assert m.events.b._reemission == mode
+
+
+@pytest.mark.skipif(not PYDANTIC_V2, reason="computed_field added in v2")
+def test_computed_field() -> None:
+    from pydantic import computed_field
+
+    class MyModel(EventedModel):
+        a: int = 1
+        b: int = 1
+
+        @computed_field
+        @property
+        def c(self) -> List[int]:
+            return [self.a, self.b]
+
+        @c.setter
+        def c(self, val: Sequence[int]) -> None:
+            self.a, self.b = val
+
+        model_config = {
+            "allow_property_setters": True,
+            "field_dependencies": {"c": ["a", "b"]},
+        }
+
+    mock_a = Mock()
+    mock_b = Mock()
+    mock_c = Mock()
+    m = MyModel()
+    m.events.a.connect(mock_a)
+    m.events.b.connect(mock_b)
+    m.events.c.connect(mock_c)
+
+    m.c = [10, 20]
+    mock_a.assert_called_with(10)
+    mock_b.assert_called_with(20)
+    mock_c.assert_called_with([10, 20])
+
+    mock_a.reset_mock()
+    mock_c.reset_mock()
+
+    m.a = 5
+    mock_a.assert_called_with(5)
+    mock_c.assert_called_with([5, 20])