tests: add test checking entity.destroy() removal of components

test/unit/entitymanager.test.js

@@ -1,5 +1,5 @@
 import test from "ava";
-import { World } from "../../src";
+import { Component, World } from "../../src";
 
 test("entity id", (t) => {
   var world = new World();
@@ -43,3 +43,40 @@ test("deferred entity remove", (t) => {
   t.is(world.entityManager.count(), 0);
   t.is(world.entityManager.entitiesToRemove.length, 0);
 });
+
+test("remove entity clears and reset components first ", (t) => {
+  class MyComponent extends Component {
+    constructor() {
+      super();
+      this.isReset = false;
+    }
+    dispose() {
+      this.isReset = true;
+      super.dispose();
+    }
+  }
+  const world = new World();
+  world.registerComponent(MyComponent, false);
+
+  let entity = world.createEntity();
+  entity.addComponent(MyComponent);
+
+  let component = entity.getComponent(MyComponent);
+  t.is(component.isReset, false);
+
+  // Deletes component immeditatly.
+  entity.remove(true);
+  t.is(component.isReset, true);
+
+  // Deletes component is a deferred manner.
+
+  entity = world.createEntity();
+  entity.addComponent(MyComponent);
+  component = entity.getComponent(MyComponent);
+  t.is(component.isReset, false);
+
+  entity.remove();
+  world.entityManager.processDeferredRemoval();
+  t.is(component.isReset, true);
+
+});