From 37406d2ff628a17ba8fd2b7b4d09db2b4f23bcd4 Mon Sep 17 00:00:00 2001
From: Rex Magana <Rex.magana@gmail.com>
Date: Sat, 23 Dec 2023 17:41:55 -0800
Subject: [PATCH] support generic actions

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

diff --git a/derive/src/action.rs b/derive/src/action.rs
index 4ebff9a..be7b020 100644
--- a/derive/src/action.rs
+++ b/derive/src/action.rs
@@ -10,14 +10,17 @@ pub fn action_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::actions::ActionBuilder for #component_name {
+        impl #impl_generics ::big_brain::actions::ActionBuilder 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, action: ::bevy::ecs::entity::Entity, _actor: ::bevy::ecs::entity::Entity) {
-            cmd.entity(action).insert(#component_name::clone(self));
+            cmd.entity(action).insert(#component_name #turbofish::clone(self));
         }
     }
 }
diff --git a/tests/derive_action.rs b/tests/derive_action.rs
index 585e79d..808cd50 100644
--- a/tests/derive_action.rs
+++ b/tests/derive_action.rs
@@ -10,3 +10,30 @@ fn check_macro() {
     let action = MyAction;
     assert_eq!(action.label(), Some("MyLabel"))
 }
+
+#[derive(Debug, Clone, Component, ActionBuilder)]
+#[action_label = "MyGenericLabel"]
+pub struct MyGenericAction<T: Clone + Send + Sync + std::fmt::Debug + 'static> {
+    pub value: T,
+}
+
+#[test]
+fn check_generic_macro() {
+    let action = MyGenericAction { value: 0 };
+    assert_eq!(action.label(), Some("MyGenericLabel"))
+}
+
+#[derive(Debug, Clone, Component, ActionBuilder)]
+#[action_label = "MyGenericWhereLabel"]
+pub struct MyGenericWhereAction<T>
+where
+    T: Clone + Send + Sync + std::fmt::Debug + 'static,
+{
+    pub value: T,
+}
+
+#[test]
+fn check_generic_where_macro() {
+    let action = MyGenericWhereAction { value: 0 };
+    assert_eq!(action.label(), Some("MyGenericWhereLabel"))
+}