Re-implement actions as derive macros instead of blanket impls

crates/gpui2/tests/action_macros.rs

@@ -0,0 +1,45 @@
+use serde_derive::Deserialize;
+
+#[test]
+fn test_derive() {
+    use gpui2 as gpui;
+
+    #[derive(PartialEq, Clone, Deserialize, gpui2_macros::Action)]
+    struct AnotherTestAction;
+
+    #[gpui2_macros::register_action]
+    #[derive(PartialEq, Clone, gpui::serde_derive::Deserialize)]
+    struct RegisterableAction {}
+
+    impl gpui::Action for RegisterableAction {
+        fn boxed_clone(&self) -> Box<dyn gpui::Action> {
+            todo!()
+        }
+
+        fn as_any(&self) -> &dyn std::any::Any {
+            todo!()
+        }
+
+        fn partial_eq(&self, _action: &dyn gpui::Action) -> bool {
+            todo!()
+        }
+
+        fn name(&self) -> &str {
+            todo!()
+        }
+
+        fn debug_name() -> &'static str
+        where
+            Self: Sized,
+        {
+            todo!()
+        }
+
+        fn build(_value: serde_json::Value) -> anyhow::Result<Box<dyn gpui::Action>>
+        where
+            Self: Sized,
+        {
+            todo!()
+        }
+    }
+}