From 003d27572f4d5c036ee759affcced1c2f0a7d62a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ivan=20=E2=80=9CCLOVIS=E2=80=9D=20Canet?=
 <ivan.canet@gmail.com>
Date: Wed, 15 Jun 2022 14:45:50 +0200
Subject: [PATCH] Inspect arguments: name, type and mutability

---
 pyo3-macros-backend/src/inspect.rs | 25 ++++++++++++++++++++++++-
 tests/test_interface.rs            |  1 +
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/pyo3-macros-backend/src/inspect.rs b/pyo3-macros-backend/src/inspect.rs
index 3046aa0e91b..58068741174 100644
--- a/pyo3-macros-backend/src/inspect.rs
+++ b/pyo3-macros-backend/src/inspect.rs
@@ -150,12 +150,35 @@ pub(crate) fn generate_fields_inspection(
         .map(|it| it.to_token_stream())
         .unwrap_or_else(|| cls.to_token_stream());
 
+    let mut args: Vec<TokenStream> = vec![];
+    for arg in &field.spec.args {
+        let name = Literal::string(&*arg.name.to_string());
+        let typ = generate_type(arg.ty)
+            .map(|it| it.to_token_stream())
+            .unwrap_or_else(|| cls.to_token_stream());
+
+        let is_mutable = arg.mutability.is_some();
+
+        args.push(quote! {
+            _pyo3::inspect::fields::ArgumentInfo {
+                name: #name,
+                kind: _pyo3::inspect::fields::ArgumentKind::PositionOrKeyword, //TODO
+                py_type: ::std::option::Option::Some(|| <#typ as _pyo3::conversion::FromPyObject>::type_input()),
+                default_value: false,
+                is_modified: #is_mutable,
+            }
+        });
+    }
+    let args_size = Literal::usize_suffixed(args.len());
+
     let output = quote! {
         fn #field_type_fn_name() -> _pyo3::inspect::types::TypeInfo {
             <#field_type as _pyo3::conversion::IntoPy<_>>::type_output()
         }
 
-        const #field_args_name: [_pyo3::inspect::fields::ArgumentInfo<'static>; 0] = []; //TODO
+        const #field_args_name: [_pyo3::inspect::fields::ArgumentInfo<'static>; #args_size] = [
+             #(#args),*
+        ];
 
         const #field_info_name: _pyo3::inspect::fields::FieldInfo<'static> = _pyo3::inspect::fields::FieldInfo {
             name: #field_name,
diff --git a/tests/test_interface.rs b/tests/test_interface.rs
index 86694db1cf7..8157baff46e 100644
--- a/tests/test_interface.rs
+++ b/tests/test_interface.rs
@@ -229,6 +229,7 @@ struct Complicated {
 #[allow(unused_variables)]
 #[pymethods]
 impl Complicated {
+    #[new]
     fn new(foo: PyObject, parent: PyObject) -> Self {
         unreachable!("This is just a stub")
     }