fix(engine-ecs): add checks against adding sole components to entities

1 files changed, 34 insertions, 3 deletions

diff --git a/engine-ecs/src/lib.rs b/engine-ecs/src/lib.rs
index 8e8cc69..450940a 100644
--- a/engine-ecs/src/lib.rs
+++ b/engine-ecs/src/lib.rs
@@ -175,7 +175,20 @@ impl World
     where
         Comps: ComponentSequence,
     {
-        self.create_ent(entity_uid, components.into_parts_array());
+        let components_parts = components.into_parts_array();
+
+        if let Some(comp_parts) = components_parts
+            .as_ref()
+            .iter()
+            .find(|comp_parts| comp_parts.is_sole)
+        {
+            panic!(
+                "Cannot spawn entity with sole component {}",
+                comp_parts.name
+            );
+        }
+
+        self.create_ent(entity_uid, components_parts);
     }
 
     /// Creates a entity with the given components. The entity will have the specified
@@ -192,10 +205,22 @@ impl World
     ) where
         Comps: ComponentSequence,
     {
+        let components_parts = components.into_parts_array();
+
+        if let Some(comp_parts) = components_parts
+            .as_ref()
+            .iter()
+            .find(|comp_parts| comp_parts.is_sole)
+        {
+            panic!(
+                "Cannot spawn entity with sole component {}",
+                comp_parts.name
+            );
+        }
+
         self.create_ent(
             entity_uid,
-            components
-                .into_parts_array()
+            components_parts
                 .into_iter()
                 .chain([EntityName { name: name.into() }.into_parts()]),
         );
@@ -203,6 +228,12 @@ impl World
 
     pub fn add_component(&mut self, entity_id: Uid, component_parts: ComponentParts)
     {
+        assert!(
+            !component_parts.is_sole,
+            "Cannot add sole component {} to an entity",
+            component_parts.name
+        );
+
         Self::add_entity_components(
             entity_id,
             [component_parts],