Declarative modules: make sure to emit doc comments and other attributes (#4236)

* Declarative modules: make sure to emmit doc comments and other attributes

* Adds a test

* Apply suggestions from code review

---------

Co-authored-by: David Hewitt <mail@davidhewitt.dev>

newsfragments/4236.fixed.md

@@ -0,0 +1 @@
+Declarative modules: do not discard doc comments on the `mod` node.

pyo3-macros-backend/src/module.rs

@@ -287,6 +287,7 @@ pub fn pymodule_module_impl(mut module: syn::ItemMod) -> Result<TokenStream> {
 
     let initialization = module_initialization(&name, ctx);
     Ok(quote!(
+        #(#attrs)*
         #vis mod #ident {
             #(#items)*
 

tests/ui/pymodule_missing_docs.rs

@@ -9,4 +9,9 @@ pub fn python_module(_m: &Bound<'_, PyModule>) -> PyResult<()> {
     Ok(())
 }
 
+#[cfg(feature = "experimental-declarative-modules")]
+/// Some module documentation
+#[pymodule]
+pub mod declarative_python_module {}
+
 fn main() {}