fix(ecs): check if entity components contains component before add

1 files changed, 24 insertions, 1 deletions

diff --git a/ecs/src/component/storage.rs b/ecs/src/component/storage.rs
index 05ede9b..944beb3 100644
--- a/ecs/src/component/storage.rs
+++ b/ecs/src/component/storage.rs
@@ -149,7 +149,7 @@ impl Storage
     pub fn add_components_to_entity(
         &mut self,
         entity_uid: EntityUid,
-        components: impl IntoIterator<Item = Box<dyn Component>>,
+        components: Vec<Box<dyn Component>>,
     ) -> Option<()>
     {
         let archetype_id = self.entity_archetype_lookup.get(&entity_uid)?;
@@ -159,6 +159,29 @@ impl Storage
 
         let archetype = self.archetypes.get_mut(archetype_index)?;
 
+        let contains_component_already = components
+            .iter()
+            .find(|component| archetype.component_ids.contains_key(&component.id()))
+            .is_some();
+
+        if contains_component_already {
+            let component_cnt = components.len();
+
+            // TODO: return error
+            panic!(
+                "Entity with UID {:?} already contains one or more component(s) ({})",
+                entity_uid,
+                components
+                    .iter()
+                    .map(|component| [component.type_name(), ", "])
+                    .flatten()
+                    .enumerate()
+                    .take_while(|(index, _)| { *index < (component_cnt * 2) - 1 })
+                    .map(|(_, component)| component)
+                    .collect::<String>()
+            );
+        }
+
         let entity = archetype.take_entity(entity_uid)?;
 
         self.push_entity(