chore: tidy

packages/entity/traits/spawner.trait.js

@@ -31,12 +31,15 @@ export class Spawner extends decorate(Trait) {
   }
 
   destroy() {
-    this.children = [];
+    while (this.children.length > 0) {
+      this.removeChild(this.children.pop());
+    }
   }
 
   constructor(entity, params, state) {
     super(entity, params, state);
     this.children = [];
+    this.childrenListeners = new Map();
     this.spawnJSONs = this.params.spawns;
   }
 
@@ -63,6 +66,16 @@ export class Spawner extends decorate(Trait) {
     return true;
   }
 
+  removeChild(child) {
+    const index = this.children.indexOf(child);
+    if (-1 !== index) {
+      this.children.splice(index, 1);
+      const listener = this.childrenListeners.get(child);
+      child.off('destroy', listener);
+      this.childrenListeners.delete(child);
+    }
+  }
+
   listeners() {
     return {
 
@@ -100,14 +113,13 @@ export class Spawner extends decorate(Trait) {
         // Add null to children to prevent race.
         const childIndex = this.children.length;
         this.children.push(null);
-        return Entity.loadOrInstance(mergedJSON).then((spawn) => {
-          this.children[childIndex] = spawn;
-          spawn.once('destroy', () => {
-            const index = this.children.indexOf(spawn);
-            this.children.splice(index, 1);
-          })
-          list.addEntity(spawn);
-          return spawn;
+        return Entity.loadOrInstance(mergedJSON).then((child) => {
+          this.children[childIndex] = child;
+          const listener = this.removeChild.bind(this, child);
+          this.childrenListeners.set(child, listener);
+          child.once('destroy', listener);
+          list.addEntity(child);
+          return child;
         });
       },