🔀 Merge pull request #111 from wrangelvid/fixed_reset_world

fix: ensure entities are only destroyed when present

Author: krispya

packages/core/src/world/world.ts

@@ -128,7 +128,13 @@ export class World {
 		const ctx = this[$internal];
 
 		// Destroy all entities so any cleanup is done.
-		this.entities.forEach((entity) => destroyEntity(this, entity));
+		this.entities.forEach((entity) => {
+			// Some relations may have caused the entity to be destroyed before
+			// we get to them in the loop.
+			if (this.has(entity)) {
+				destroyEntity(this, entity)
+			}
+		});
 
 		ctx.entityIndex = createEntityIndex(this.#id);
 		ctx.entityTraits.clear();

packages/core/tests/world.test.ts

@@ -1,5 +1,5 @@
 import { beforeEach, describe, expect, it } from 'vitest';
-import { createWorld, TraitInstance } from '../src';
+import { createWorld, relation, TraitInstance } from '../src';
 import { trait } from '../src/trait/trait';
 import { universe } from '../src/universe/universe';
 
@@ -27,6 +27,24 @@ describe('World', () => {
 		expect(world.entities.length).toBe(1);
 	});
 
+	it('reset should remove entities with auto-remove relations', () => {
+		const Node = trait();
+		const ChildOf = relation({ autoRemoveTarget: true, exclusive: true });
+
+		const world = createWorld();
+
+		// Create a parent node and a child node.
+		const parentNode = world.spawn(Node);
+		world.spawn(Node, ChildOf(parentNode));
+
+		// Expect this to not throw, since the ChildOf relation will automatically
+		// remove the child node when the parent node is destroyed first.
+		expect(() => world.reset()).not.toThrow();
+
+		// Always has one entity that is the world itself.
+		expect(world.entities.length).toBe(1);
+	});
+
 	it('errors if more than 16 worlds are created', () => {
 		for (let i = 0; i < 16; i++) {
 			createWorld();