From df6cc6d6981e3952099c81b8af8e3d9cb018de1b Mon Sep 17 00:00:00 2001
From: Jacob Biggs <biggs.jacob@gmail.com>
Date: Sun, 24 Mar 2024 17:37:48 -0500
Subject: [PATCH] Add support for generic types in ScorerBuilder

---
 derive/src/scorer.rs   | 13 +++++++++----
 tests/derive_scorer.rs | 27 +++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/derive/src/scorer.rs b/derive/src/scorer.rs
index a4b167a..0920467 100644
--- a/derive/src/scorer.rs
+++ b/derive/src/scorer.rs
@@ -10,14 +10,17 @@ pub fn scorer_builder_impl(input: proc_macro::TokenStream) -> proc_macro::TokenS
     let label = get_label(&input);
 
     let component_name = input.ident;
+    let generics = input.generics;
+    let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
+
     let component_string = component_name.to_string();
-    let build_method = build_method(&component_name);
+    let build_method = build_method(&component_name, &ty_generics);
     let label_method = label_method(
         label.unwrap_or_else(|| LitStr::new(&component_string, component_name.span())),
     );
 
     let gen = quote! {
-        impl ::big_brain::scorers::ScorerBuilder for #component_name {
+        impl #impl_generics ::big_brain::scorers::ScorerBuilder for #component_name #ty_generics #where_clause {
             #build_method
             #label_method
         }
@@ -48,10 +51,12 @@ fn get_label(input: &DeriveInput) -> Option<LitStr> {
     label
 }
 
-fn build_method(component_name: &Ident) -> TokenStream {
+fn build_method(component_name: &Ident, ty_generics: &syn::TypeGenerics) -> TokenStream {
+    let turbofish = ty_generics.as_turbofish();
+
     quote! {
         fn build(&self, cmd: &mut ::bevy::ecs::system::Commands, scorer: ::bevy::ecs::entity::Entity, _actor: ::bevy::ecs::entity::Entity) {
-            cmd.entity(scorer).insert(#component_name::clone(self));
+            cmd.entity(scorer).insert(#component_name  #turbofish::clone(self));
         }
     }
 }
diff --git a/tests/derive_scorer.rs b/tests/derive_scorer.rs
index f6881fc..25d995b 100644
--- a/tests/derive_scorer.rs
+++ b/tests/derive_scorer.rs
@@ -12,3 +12,30 @@ fn check_macro() {
     let scorer = MyScorer;
     assert_eq!(scorer.label(), Some("MyLabel"))
 }
+
+#[derive(Debug, Clone, Component, ScorerBuilder)]
+#[scorer_label = "MyGenericLabel"]
+pub struct MyGenericScorer<T: Clone + Send + Sync + std::fmt::Debug + 'static> {
+    pub value: T,
+}
+
+#[test]
+fn check_generic_macro() {
+    let scorer = MyGenericScorer { value: 0 };
+    assert_eq!(scorer.label(), Some("MyGenericLabel"))
+}
+
+#[derive(Debug, Clone, Component, ScorerBuilder)]
+#[scorer_label = "MyGenericWhereLabel"]
+pub struct MyGenericWhereScorer<T>
+    where
+        T: Clone + Send + Sync + std::fmt::Debug + 'static,
+{
+    pub value: T,
+}
+
+#[test]
+fn check_generic_where_macro() {
+    let scorer = MyGenericWhereScorer { value: 0 };
+    assert_eq!(scorer.label(), Some("MyGenericWhereLabel"))
+}