#[deprecated] does not work with #[getter] (#256)

## Summary

Fixes a bug where `#[deprecated]` attributes on getter/setter methods
were not being translated to `@typing_extensions.deprecated` decorators
in generated Python stub files.

**Before:**
```python
@Property  
def deprecated_getter(self) -> int: ...
```

**After:**
```python
@typing_extensions.deprecated("[Since 1.0.0] This method is deprecated")
@Property
def deprecated_getter(self) -> int: ...
```

## Root Cause

The `MemberInfo` and `MemberDef` structs lacked a `deprecated` field,
causing deprecation information to be lost during stub generation. While
regular methods (`#[pymethods]`) correctly handled deprecation,
getter/setter methods (`#[getter]`/`#[setter]`) did not.

## Changes

### Core Infrastructure
- **Type definitions**: Added `deprecated: Option<DeprecatedInfo>` field
to `MemberInfo` and `MemberDef` structs
- **Proc macro**: Modified member extraction to collect `#[deprecated]`
attributes using existing `extract_deprecated()` function
- **Type imports**: Added automatic `typing_extensions` import when
deprecated members are present

### Code Generation
- **Getters**: Updated `GetterDisplay` to output deprecation decorators
before `@property`
- **Setters**: Updated `SetterDisplay` to output deprecation decorators
before `@{name}.setter`
- **Constants**: Added warning log for deprecated constants (cannot have
decorators in Python syntax)

### Comprehensive Test Coverage
Added examples for all PyO3 item types that support `#[deprecated]`:

| Item Type | Rust Code | Generated Python Stub |
|-----------|-----------|----------------------|
| **Function** | `#[deprecated] #[pyfunction] fn deprecated_function()`
| `@typing_extensions.deprecated(...) def deprecated_function()` |
| **Method** | `#[deprecated] fn deprecated_method(&self)` |
`@typing_extensions.deprecated(...) def deprecated_method(self)` |
| **Getter** | `#[deprecated] #[getter] fn deprecated_getter(&self)` |
`@typing_extensions.deprecated(...) @Property def
deprecated_getter(self)` |
| **Setter** | `#[deprecated] #[setter] fn set_y(&mut self, value)` |
`@typing_extensions.deprecated(...) @y.setter def y(self, value)` |
| **Classmethod** | `#[deprecated] #[classmethod] fn
deprecated_classmethod()` | `@typing_extensions.deprecated(...)
@classmethod def deprecated_classmethod(cls)` |
| **Staticmethod** | `#[deprecated] #[staticmethod] fn
deprecated_staticmethod()` | `@typing_extensions.deprecated(...)
@staticmethod def deprecated_staticmethod()` |

### Constants Handling
Constants with `#[deprecated]` are handled specially:
- **Collection**: Deprecated attributes are collected from constants
during proc macro processing
- **Warning**: A helpful warning is logged during stub generation:
  ```
WARN: Ignoring #[deprecated] on constant 'NUM3': Python constants cannot
have decorators.
  Consider using a function instead if deprecation is needed.
  ```
- **No output**: No deprecated decorator is generated (would cause
Python syntax error)

## Example Usage

```rust
#[gen_stub_pymethods]
#[pymethods]
impl MyClass {
    #[deprecated(since = "1.0.0", note = "Use new_method instead")]
    #[getter]
    fn old_property(&self) -> i32 {
        self.value
    }
    
    #[deprecated(since = "1.0.0", note = "This constant is deprecated")]
    #[classattr]
    const OLD_CONSTANT: i32 = 42; // Will show warning
}
```

Generated stub:
```python
class MyClass:
    OLD_CONSTANT: int = 42  # No decorator (with warning logged)
    
    @typing_extensions.deprecated("[Since 1.0.0] Use new_method instead")
    @Property
    def old_property(self) -> int: ...
```

## Verification

- ✅ All existing tests pass
- ✅ Type checking (pyright) passes  
- ✅ Generated stubs include proper deprecation decorators
- ✅ Warning system works for unsupported scenarios
- ✅ Backward compatibility maintained
- ✅ Comprehensive coverage of all PyO3 deprecated item types

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: termoshtt

examples/pure/pure.pyi

@@ -16,6 +16,10 @@ class A:
     r"""
     class attribute NUM1
     """
+    NUM3: builtins.int = 3
+    r"""
+    deprecated class attribute NUM3 (will show warning)
+    """
     NUM2: builtins.int
     r"""
     class attribute NUM2
@@ -27,26 +31,40 @@ class A:
         default = 2
         ```
         """
+    @property
+    def y(self) -> builtins.int: ...
+    @typing_extensions.deprecated("[Since 1.0.0] This method is deprecated")
+    @property
+    def deprecated_getter(self) -> builtins.int: ...
     @x.setter
     def x(self, value: builtins.int) -> None:
         r"""
         ```python
         default = 2
         ```
         """
+    @typing_extensions.deprecated("[Since 1.0.0] This setter is deprecated")
+    @y.setter
+    def y(self, value: builtins.int) -> None: ...
     def __new__(cls, x:builtins.int) -> A:
         r"""
         This is a constructor of :class:`A`.
         """
     @classmethod
     def classmethod_test1(cls) -> None: ...
+    @typing_extensions.deprecated("[Since 1.0.0] This classmethod is deprecated")
+    @classmethod
+    def deprecated_classmethod(cls) -> None: ...
     @classmethod
     def classmethod_test2(cls) -> None: ...
     def show_x(self) -> None: ...
     def ref_test(self, x:dict) -> dict: ...
     async def async_get_x(self) -> builtins.int: ...
     @typing_extensions.deprecated("[Since 1.0.0] This method is deprecated")
     def deprecated_method(self) -> None: ...
+    @typing_extensions.deprecated("[Since 1.0.0] This staticmethod is deprecated")
+    @staticmethod
+    def deprecated_staticmethod() -> builtins.int: ...
 
 class B(A):
     ...

examples/pure/src/lib.rs

@@ -59,11 +59,14 @@ struct A {
     #[gen_stub(default = A::default().x)]
     #[pyo3(get, set)]
     x: usize,
+
+    #[pyo3(get)]
+    y: usize,
 }
 
 impl Default for A {
     fn default() -> Self {
-        Self { x: 2 }
+        Self { x: 2, y: 10 }
     }
 }
 
@@ -73,11 +76,16 @@ impl A {
     /// This is a constructor of :class:`A`.
     #[new]
     fn new(x: usize) -> Self {
-        Self { x }
+        Self { x, y: 10 }
     }
     /// class attribute NUM1
     #[classattr]
     const NUM1: usize = 2;
+
+    /// deprecated class attribute NUM3 (will show warning)
+    #[deprecated(since = "1.0.0", note = "This constant is deprecated")]
+    #[classattr]
+    const NUM3: usize = 3;
     /// class attribute NUM2
     #[expect(non_snake_case)]
     #[classattr]
@@ -89,6 +97,12 @@ impl A {
         _ = cls;
     }
 
+    #[deprecated(since = "1.0.0", note = "This classmethod is deprecated")]
+    #[classmethod]
+    fn deprecated_classmethod(cls: &Bound<'_, PyType>) {
+        _ = cls;
+    }
+
     #[classmethod]
     fn classmethod_test2(_: &Bound<'_, PyType>) {}
 
@@ -111,13 +125,31 @@ impl A {
     fn deprecated_method(&self) {
         println!("This method is deprecated");
     }
+
+    #[deprecated(since = "1.0.0", note = "This method is deprecated")]
+    #[getter]
+    fn deprecated_getter(&self) -> usize {
+        self.x
+    }
+
+    #[deprecated(since = "1.0.0", note = "This setter is deprecated")]
+    #[setter]
+    fn set_y(&mut self, value: usize) {
+        self.y = value;
+    }
+
+    #[deprecated(since = "1.0.0", note = "This staticmethod is deprecated")]
+    #[staticmethod]
+    fn deprecated_staticmethod() -> usize {
+        42
+    }
 }
 
 #[gen_stub_pyfunction]
 #[pyfunction]
 #[pyo3(signature = (x = 2))]
 fn create_a(x: usize) -> A {
-    A { x }
+    A { x, y: 10 }
 }
 
 #[gen_stub_pyclass]

pyo3-stub-gen-derive/src/gen_stub.rs

@@ -17,18 +17,21 @@
 //!                 r#type: <String as ::pyo3_stub_gen::PyStubType>::type_output,
 //!                 doc: "",
 //!                 default: None,
+//!                 deprecated: None,
 //!             },
 //!             MemberInfo {
 //!                 name: "ndim",
 //!                 r#type: <usize as ::pyo3_stub_gen::PyStubType>::type_output,
 //!                 doc: "",
 //!                 default: None,
+//!                 deprecated: None,
 //!             },
 //!             MemberInfo {
 //!                 name: "description",
 //!                 r#type: <Option<String> as ::pyo3_stub_gen::PyStubType>::type_output,
 //!                 doc: "",
 //!                 default: None,
+//!                 deprecated: None,
 //!             },
 //!         ],
 //!         setters: &[],

pyo3-stub-gen-derive/src/gen_stub/member.rs

@@ -17,6 +17,7 @@ pub struct MemberInfo {
     name: String,
     r#type: TypeOrOverride,
     default: Option<Expr>,
+    deprecated: Option<crate::gen_stub::attr::DeprecatedInfo>,
 }
 
 impl MemberInfo {
@@ -67,6 +68,7 @@ impl MemberInfo {
                     r#type: extract_return_type(&sig.output, attrs)?
                         .expect("Getter must return a type"),
                     default,
+                    deprecated: crate::gen_stub::attr::extract_deprecated(attrs),
                 });
             }
         }
@@ -112,6 +114,7 @@ impl MemberInfo {
                     name: name.unwrap_or(fn_setter_name),
                     r#type,
                     default,
+                    deprecated: crate::gen_stub::attr::extract_deprecated(attrs),
                 });
             }
         }
@@ -127,6 +130,7 @@ impl MemberInfo {
             name: sig.ident.to_string(),
             r#type: extract_return_type(&sig.output, attrs)?.expect("Getter must return a type"),
             default,
+            deprecated: crate::gen_stub::attr::extract_deprecated(attrs),
         })
     }
     pub fn new_classattr_const(item: ImplItemConst) -> Result<Self> {
@@ -144,6 +148,7 @@ impl MemberInfo {
             name: ident.to_string(),
             r#type: TypeOrOverride::RustType { r#type: ty },
             default: Some(expr),
+            deprecated: crate::gen_stub::attr::extract_deprecated(&attrs),
         })
     }
 }
@@ -162,11 +167,13 @@ impl TryFrom<Field> for MemberInfo {
         }
         let doc = extract_documents(&attrs).join("\n");
         let default = parse_gen_stub_default(&attrs)?;
+        let deprecated = crate::gen_stub::attr::extract_deprecated(&attrs);
         Ok(Self {
             name: field_name.unwrap_or(ident.unwrap().to_string()),
             r#type: TypeOrOverride::RustType { r#type: ty },
             doc,
             default,
+            deprecated,
         })
     }
 }
@@ -178,6 +185,7 @@ impl ToTokens for MemberInfo {
             r#type,
             doc,
             default,
+            deprecated,
         } = self;
         let default = default
             .as_ref()
@@ -206,13 +214,25 @@ impl ToTokens for MemberInfo {
                     &DEFAULT
                 })}
             });
+        let deprecated_info = deprecated
+            .as_ref()
+            .map(|deprecated| {
+                quote! {
+                    Some(::pyo3_stub_gen::type_info::DeprecatedInfo {
+                        since: #deprecated.since,
+                        note: #deprecated.note,
+                    })
+                }
+            })
+            .unwrap_or_else(|| quote! { None });
         match r#type {
             TypeOrOverride::RustType { r#type: ty } => tokens.append_all(quote! {
                 ::pyo3_stub_gen::type_info::MemberInfo {
                     name: #name,
                     r#type: <#ty as ::pyo3_stub_gen::PyStubType>::type_output,
                     doc: #doc,
                     default: #default,
+                    deprecated: #deprecated_info,
                 }
             }),
             TypeOrOverride::OverrideType {
@@ -225,6 +245,7 @@ impl ToTokens for MemberInfo {
                         r#type: || ::pyo3_stub_gen::TypeInfo { name: #type_repr.to_string(), import: ::std::collections::HashSet::from([#(#imports.into(),)*]) },
                         doc: #doc,
                         default: #default,
+                        deprecated: #deprecated_info,
                     }
                 })
             }

pyo3-stub-gen-derive/src/gen_stub/pyclass.rs

@@ -141,7 +141,7 @@ mod test {
             "#,
         )?;
         let out = PyClassInfo::try_from(input)?.to_token_stream();
-        insta::assert_snapshot!(format_as_value(out), @r#"
+        insta::assert_snapshot!(format_as_value(out), @r###"
         ::pyo3_stub_gen::type_info::PyClassInfo {
             pyclass_name: "Placeholder",
             struct_id: std::any::TypeId::of::<PyPlaceholder>,
@@ -151,26 +151,29 @@ mod test {
                     r#type: <String as ::pyo3_stub_gen::PyStubType>::type_output,
                     doc: "",
                     default: None,
+                    deprecated: None,
                 },
                 ::pyo3_stub_gen::type_info::MemberInfo {
                     name: "ndim",
                     r#type: <usize as ::pyo3_stub_gen::PyStubType>::type_output,
                     doc: "",
                     default: None,
+                    deprecated: None,
                 },
                 ::pyo3_stub_gen::type_info::MemberInfo {
                     name: "description",
                     r#type: <Option<String> as ::pyo3_stub_gen::PyStubType>::type_output,
                     doc: "",
                     default: None,
+                    deprecated: None,
                 },
             ],
             setters: &[],
             module: Some("my_module"),
             doc: "",
             bases: &[],
         }
-        "#);
+        "###);
         Ok(())
     }
 

pyo3-stub-gen-derive/src/gen_stub/pyclass_complex_enum.rs

@@ -120,7 +120,7 @@ mod test {
             "#,
         )?;
         let out = PyComplexEnumInfo::try_from(input)?.to_token_stream();
-        insta::assert_snapshot!(format_as_value(out), @r#"
+        insta::assert_snapshot!(format_as_value(out), @r###"
         ::pyo3_stub_gen::type_info::PyComplexEnumInfo {
             pyclass_name: "Placeholder",
             enum_id: std::any::TypeId::of::<PyPlaceholder>,
@@ -133,6 +133,7 @@ mod test {
                             r#type: <String as ::pyo3_stub_gen::PyStubType>::type_output,
                             doc: "",
                             default: None,
+                            deprecated: None,
                         },
                     ],
                     module: None,
@@ -154,12 +155,14 @@ mod test {
                             r#type: <i32 as ::pyo3_stub_gen::PyStubType>::type_output,
                             doc: "",
                             default: None,
+                            deprecated: None,
                         },
                         ::pyo3_stub_gen::type_info::MemberInfo {
                             name: "_1",
                             r#type: <f64 as ::pyo3_stub_gen::PyStubType>::type_output,
                             doc: "",
                             default: None,
+                            deprecated: None,
                         },
                     ],
                     module: None,
@@ -198,6 +201,7 @@ mod test {
                             r#type: <usize as ::pyo3_stub_gen::PyStubType>::type_output,
                             doc: "",
                             default: None,
+                            deprecated: None,
                         },
                     ],
                     module: None,
@@ -223,7 +227,7 @@ mod test {
             module: Some("my_module"),
             doc: "",
         }
-        "#);
+        "###);
         Ok(())
     }