Adding duplicate entity checks as well

assets/scenes/00.scene

@@ -1 +1,2 @@
 00/a.entity
+00/a.entity

assets/scenes/00/a.entity

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

src/save.rs

@@ -100,7 +100,6 @@ 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();
@@ -111,12 +110,20 @@ impl SaveEntity {
                     let c2 = &entity.components[j];
                     let t1 = c1.type_id;
                     let t2 = c2.type_id;
-                    if t1 == t2 {
+                    if cfg!(debug_assertions) {
+                        debug_assert!(
+                            t1 != t2,
+                            "Duplicate components in {:?}: \n\t{:?}\n\t{:?}",
+                            load_context.asset_path(),
+                            c1.data,
+                            c2.data
+                        );
+                    } else {
                         error!(
                             "Duplicate components in {:?}: \n\t{:?}\n\t{:?}",
                             load_context.asset_path(),
                             c1.data,
-                            c2.data,
+                            c2.data
                         );
                     }
                 }
@@ -198,6 +205,37 @@ impl AssetLoader for SaveSceneLoader {
             .map(|path| load_context.load(path))
             .collect();
 
+        // Assert there are no duplicate entities in the file
+        {
+            let l = entities.len();
+            (0..l).for_each(|i| {
+                (i..l).for_each(|j| {
+                    if i != j {
+                        let e1 = &entities[i];
+                        let e2 = &entities[j];
+                        if cfg!(debug_assertions) {
+                            debug_assert!(
+                                e1 != e2,
+                                "Duplicate entities in scene {:?}:\n\t{:?}\n\t{:?}",
+                                load_context.asset_path(),
+                                e1,
+                                e2
+                            );
+                        } else {
+                            if e1 == e2 {
+                                error!(
+                                    "Duplicate entities in scene {:?}:\n\t{:?}\n\t{:?}",
+                                    load_context.asset_path(),
+                                    e1,
+                                    e2
+                                )
+                            }
+                        }
+                    }
+                });
+            });
+        }
+
         Ok(SaveScene { entities })
     }