fix(oapi-macros): Support the generic parameters. #945

crates/oapi-macros/src/endpoint/mod.rs

@@ -1,6 +1,6 @@
 use proc_macro2::{Span, TokenStream};
 use quote::{quote, ToTokens};
-use syn::{Expr, Ident, ImplItem, Item, Pat, ReturnType, Signature, Type};
+use syn::{Expr, Generics, Ident, ImplItem, Item, Pat, ReturnType, Signature, Type};
 
 use crate::doc_comment::CommentAttributes;
 use crate::{omit_type_path_lifetimes, parse_input_type, Array, DiagResult, InputType, Operation};
@@ -14,6 +14,7 @@ fn metadata(
     attr: EndpointAttr,
     name: &Ident,
     mut modifiers: Vec<TokenStream>,
+    generics: &Generics,
 ) -> DiagResult<TokenStream> {
     let tfn = Ident::new(
         &format!("__macro_gen_oapi_endpoint_type_id_{}", name),
@@ -46,17 +47,19 @@ fn metadata(
             #(#modifiers)*
         }})
     };
+    let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
+
     let stream = quote! {
-        fn #tfn() -> ::std::any::TypeId {
-            ::std::any::TypeId::of::<#name>()
+        fn #tfn #impl_generics() -> ::std::any::TypeId #where_clause {
+            ::std::any::TypeId::of::<#name #ty_generics>()
         }
-        fn #cfn() -> #oapi::oapi::Endpoint {
+        fn #cfn #impl_generics() -> #oapi::oapi::Endpoint #where_clause {
             let mut components = #oapi::oapi::Components::new();
             let status_codes: &[#salvo::http::StatusCode] = &#status_codes;
             let mut operation = #oapi::oapi::Operation::new();
             #modifiers
             if operation.operation_id.is_none() {
-                operation.operation_id = Some(#oapi::oapi::naming::assign_name::<#name>(#oapi::oapi::naming::NameRule::Auto));
+                operation.operation_id = Some(#oapi::oapi::naming::assign_name::<#name #ty_generics>(#oapi::oapi::naming::NameRule::Auto));
             }
             if !status_codes.is_empty() {
                 let responses = std::ops::DerefMut::deref_mut(&mut operation.responses);
@@ -117,7 +120,7 @@ pub(crate) fn generate(mut attr: EndpointAttr, input: Item) -> syn::Result<Token
             };
 
             let (hfn, modifiers) = handle_fn(&salvo, &oapi, sig)?;
-            let meta = metadata(&salvo, &oapi, attr, name, modifiers)?;
+            let meta = metadata(&salvo, &oapi, attr, name, modifiers, &sig.generics)?;
             Ok(quote! {
                 #sdef
                 #[#salvo::async_trait]
@@ -153,10 +156,16 @@ pub(crate) fn generate(mut attr: EndpointAttr, input: Item) -> syn::Result<Token
             };
             let (hfn, modifiers) = handle_fn(&salvo, &oapi, &hmtd.sig)?;
             let ty = &item_impl.self_ty;
-            let (impl_generics, _, where_clause) = &item_impl.generics.split_for_impl();
-            let name = Ident::new(&ty.to_token_stream().to_string(), Span::call_site());
-            let meta = metadata(&salvo, &oapi, attr, &name, modifiers)?;
-
+            let (impl_generics, ty_generics, where_clause) = &item_impl.generics.split_for_impl();
+            let name = ty
+                .to_token_stream()
+                .to_string()
+                .to_owned()
+                .trim_end_matches(&ty_generics.to_token_stream().to_string())
+                .trim()
+                .to_owned();
+            let name = Ident::new(&name, Span::call_site());
+            let meta = metadata(&salvo, &oapi, attr, &name, modifiers, &item_impl.generics)?;
             Ok(quote! {
                 #item_impl
                 #[#salvo::async_trait]

crates/oapi-macros/src/lib.rs

@@ -56,7 +56,12 @@ pub fn endpoint(attr: TokenStream, input: TokenStream) -> TokenStream {
     let attr = syn::parse_macro_input!(attr as EndpointAttr);
     let item = parse_macro_input!(input as Item);
     match endpoint::generate(attr, item) {
-        Ok(stream) => stream.into(),
+        Ok(stream) => {
+            // Temporary debug printing.
+            println!("{}", stream.to_token_stream());
+
+            stream.into()
+        }
         Err(e) => e.to_compile_error().into(),
     }
 }

crates/oapi-macros/tests/endpoint_tests.rs

@@ -1,3 +1,5 @@
+use std::fmt::Debug;
+
 use assert_json_diff::assert_json_eq;
 use salvo::oapi::extract::*;
 use salvo::prelude::*;
@@ -43,3 +45,51 @@ fn test_endpoint_hello() {
         })
     );
 }
+
+#[test]
+fn test_endpoint_generic() {
+    struct Generic<T: Sized>(T);
+
+    #[endpoint]
+    impl<T: Sized> Generic<T>
+    where
+        T: Send + Sync + 'static,
+    {
+        async fn handle(name: QueryParam<String, false>) -> String {
+            format!("[Generic] Hello, {}!", name.as_deref().unwrap_or("World"))
+        }
+    }
+
+    let router = Router::new().push(Router::with_path("generic").get(Generic(())));
+
+    let doc = OpenApi::new("test api", "0.0.1").merge_router(&router);
+    assert_json_eq!(
+        doc,
+        json!({
+            "openapi":"3.1.0",
+            "info":{
+                "title":"test api",
+                "version":"0.0.1"
+            },
+            "paths":{
+                "/generic":{
+                    "get":{
+                        "operationId":"endpoint_tests.test_endpoint_generic.Generic",
+                        "parameters":[{
+                                "name":"name",
+                                "in":"query",
+                                "description":"Get parameter `name` from request url query.",
+                                "required":false,"schema":{"type":"string"}
+                            }],
+                        "responses":{
+                            "200":{
+                                "description":"Ok",
+                                "content":{"text/plain":{"schema":{"type":"string"}}}
+                            }
+                        }
+                    }
+                }
+            }
+        })
+    );
+}