Catching duplicate component (types) in entities

assets/scenes/00/a.entity

@@ -1 +1,2 @@
 name "Hello world"
+name "Hello bevy"

src/save.rs

@@ -1,3 +1,5 @@
+use std::any::TypeId;
+
 use crate::prelude::*;
 
 type ParseFn =
@@ -51,7 +53,12 @@ pub(crate) struct SaveScene {
 // Ironically we basically want DynamicEntity: https://docs.rs/bevy/latest/bevy/scene/struct.DynamicEntity.html
 #[derive(Asset, TypePath, Default)]
 pub(crate) struct SaveEntity {
-    components: Vec<Box<dyn Reflect>>,
+    components: Vec<SaveEntityComponent>,
+}
+
+struct SaveEntityComponent {
+    type_id: TypeId,
+    data: Box<dyn Reflect>,
 }
 
 impl SaveEntity {
@@ -74,8 +81,13 @@ impl SaveEntity {
 
                 // Run line against all parsers
                 for f in fns {
-                    if let Ok(v) = f(&tokens) {
+                    if let Ok(c) = f(&tokens) {
-                        entity.components.push(v);
+                        // Bundle the Type ID with this entry for auditing purposes
+                        let t = c.get_represented_type_info().unwrap().type_id();
+                        entity.components.push(SaveEntityComponent {
+                            type_id: t,
+                            data: c,
+                        });
                         good = true;
                     }
                 }
@@ -88,6 +100,29 @@ impl SaveEntity {
                     );
                 }
             });
+
+        // Check for duplicate component types and emit an error
+        // TODO: It would be nice if this emitted a line refernece instead of a parsed struct!
+        let l = entity.components.len();
+        (0..l).for_each(|i| {
+            (i..l).for_each(|j| {
+                if i != j {
+                    let c1 = &entity.components[i];
+                    let c2 = &entity.components[j];
+                    let t1 = c1.type_id;
+                    let t2 = c2.type_id;
+                    if t1 == t2 {
+                        error!(
+                            "Duplicate components in {:?}: \n\t{:?}\n\t{:?}",
+                            load_context.asset_path(),
+                            c1.data,
+                            c2.data,
+                        );
+                    }
+                }
+            });
+        });
+
         Ok(entity)
     }
 }
@@ -239,8 +274,8 @@ fn spawn_entities(
 
         // Add each component to the entity
         debug!("Populating entity with components {:?}", entity);
-        save_entity.components.iter().for_each(|component| {
+        save_entity.components.iter().for_each(|item| {
-            e.insert_reflect(component.clone_value());
+            e.insert_reflect(item.data.clone_value());
         });
     });
 }