feat: Enhance event system and add comprehensive tests for event handling and history management

Author: DonColon

src/core/ecs/Entity.ts

@@ -55,9 +55,7 @@ export class Entity {
 	}
 
 	public addComponent<T extends JsonSchema>(componentType: ComponentConstructor<T>, data: T): this {
-		const world = this.world ?? ServiceRegistry.get<World>(World.name);
-
-		if (!world.hasComponent(componentType)) {
+		if (!this.world.hasComponent(componentType)) {
 			throw new GameError(`${componentType.name} not defined in world`);
 		}
 
@@ -104,9 +102,7 @@ export class Entity {
 	}
 
 	public addState(stateType: GameStateConstructor): this {
-		const world = this.world ?? ServiceRegistry.get<World>(World.name);
-
-		if (!world.hasEntityState(stateType)) {
+		if (!this.world.hasEntityState(stateType)) {
 			throw new GameError(`${stateType.name} not defined in world`);
 		}
 

src/core/ecs/World.ts

@@ -188,6 +188,8 @@ export class World {
 			binaryInsert(this.updateSchedule, system, System.byPriority);
 		} else if (system instanceof RenderSystem) {
 			binaryInsert(this.renderSchedule, system, System.byPriority);
+		} else {
+			throw new GameError(`System ${system.constructor.name} is neither an UpdateSystem nor a RenderSystem`);
 		}
 	}
 
@@ -205,6 +207,8 @@ export class World {
 			this.updateSchedule = this.updateSchedule.filter(s => s !== system);
 		} else if (system instanceof RenderSystem) {
 			this.renderSchedule = this.renderSchedule.filter(s => s !== system);
+		} else {
+			throw new GameError(`System ${system.constructor.name} is neither an UpdateSystem nor a RenderSystem`);
 		}
 	}
 

test/core/ecs/Component.spec.ts

@@ -1 +1,40 @@
-import { test, expect, suite } from "vitest";import { Component } from "../../../src/core/ecs/Component";import { JsonSchema } from "../../../src/core/ecs/JsonSchema";suite("Component Test Suite", () => {	interface Point extends JsonSchema {		x: number;		y: number;	}	test("Parse a component from json", () => {		const json = '{"x": 10, "y": 20}';		const component = Component.parse<Point>(json);		expect(component.toObject()).toEqual({ x: 10, y: 20 });	});	test("Clone a component", () => {		const component = new Component<Point>({ x: 10, y: 20 });		const clone = component.clone();		expect(clone.toObject()).toEqual({ x: 10, y: 20 });	});	test("Copy a component", () => {		const component = new Component<Point>({ x: 10, y: 20 });		const other = new Component<Point>({ x: 50, y: 50 });		component.copy(other);		expect(component.toObject()).toEqual({ x: 50, y: 50 });	});	test("Update a component", () => {		const component = new Component<Point>({ x: 10, y: 20 });		component.update({ x: 50, y: 50 });		expect(component.toObject()).toEqual({ x: 50, y: 50 });	});	test("Convert a component to string", () => {		const component = new Component<Point>({ x: 10, y: 20 });		expect(component.toString()).toEqual('{\n\t"x": 10,\n\t"y": 20\n}');	});});
+import { test, expect, suite } from "vitest";
+import { Component } from "@/core/ecs/Component";
+import { JsonSchema } from "@/core/ecs/JsonSchema";
+
+suite("Component Test Suite", () => {
+	interface Point extends JsonSchema {
+		x: number;
+		y: number;
+	}
+
+	test("Parse a component from json", () => {
+		const json = '{"x": 10, "y": 20}';
+		const component = Component.parse<Point>(json);
+		expect(component.toObject()).toEqual({ x: 10, y: 20 });
+	});
+
+	test("Clone a component", () => {
+		const component = new Component<Point>({ x: 10, y: 20 });
+		const clone = component.clone();
+		expect(clone.toObject()).toEqual({ x: 10, y: 20 });
+	});
+
+	test("Copy a component", () => {
+		const component = new Component<Point>({ x: 10, y: 20 });
+		const other = new Component<Point>({ x: 50, y: 50 });
+		component.copy(other);
+		expect(component.toObject()).toEqual({ x: 50, y: 50 });
+	});
+
+	test("Update a component", () => {
+		const component = new Component<Point>({ x: 10, y: 20 });
+		component.update({ x: 50, y: 50 });
+		expect(component.toObject()).toEqual({ x: 50, y: 50 });
+	});
+
+	test("Convert a component to string", () => {
+		const component = new Component<Point>({ x: 10, y: 20 });
+		expect(component.toString()).toEqual('{\n\t"x": 10,\n\t"y": 20\n}');
+	});
+});

test/core/ecs/Entity.spec.ts

@@ -1,11 +1,11 @@
 import { test, expect, suite } from "vitest";
-import { Entity } from "../../../src/core/ecs/Entity";
-import { Component } from "../../../src/core/ecs/Component";
-import { World } from "../../../src/core/ecs/World";
-import { GameState } from "../../../src/core/GameState";
-import { GameStateManager } from "../../../src/core/GameStateManager";
-import { GameError } from "../../../src/core/GameError";
-import { ServiceRegistry } from "../../../src/core/service/ServiceRegistry";
+import { Entity } from "@/core/ecs/Entity";
+import { Component } from "@/core/ecs/Component";
+import { World } from "@/core/ecs/World";
+import { GameState } from "@/core/GameState";
+import { GameStateManager } from "@/core/GameStateManager";
+import { GameError } from "@/core/GameError";
+import { ServiceRegistry } from "@/core/service/ServiceRegistry";
 
 suite("Entity Test Suite", () => {
 	class PointComponent extends Component<{
@@ -180,4 +180,16 @@ suite("Entity Test Suite", () => {
 		entity.enable();
 		expect(entity.isEnabled()).toBeTruthy();
 	});
+
+	test("Add component and state without world service", () => {
+		// Test that accessing world property directly works when injected
+		const entity = new Entity();
+		entity.addComponent(PointComponent, { x: 100, y: 200 });
+		expect(entity.getComponentData(PointComponent)).toEqual({ x: 100, y: 200 });
+
+		entity.addState(JumpState);
+		const stateManager = entity.getStateManager();
+		const registeredStates = stateManager.getRegisteredStates();
+		expect(registeredStates[0]).toBeInstanceOf(JumpState);
+	});
 });

test/core/ecs/Query.spec.ts

@@ -1,9 +1,9 @@
 import { test, expect, suite } from "vitest";
-import { Component } from "../../../src/core/ecs/Component";
-import { World } from "../../../src/core/ecs/World";
-import { Query } from "../../../src/core/ecs/Query";
-import { ServiceRegistry } from "../../../src/core/service/ServiceRegistry";
-import { EventSystem } from "../../../src/core/events/EventSystem";
+import { Component } from "@/core/ecs/Component";
+import { World } from "@/core/ecs/World";
+import { Query } from "@/core/ecs/Query";
+import { ServiceRegistry } from "@/core/service/ServiceRegistry";
+import { EventSystem } from "@/core/events/EventSystem";
 
 suite("Query Test Suite", () => {
 	class PointComponent extends Component<{
@@ -59,4 +59,101 @@ suite("Query Test Suite", () => {
 		expect(results[0].getID()).toEqual("1337");
 		expect(results[1].getID()).toEqual("7331");
 	});
+
+	test("Query removes entity when component is added that is in blocklist", () => {
+		const query = new Query({
+			allowlist: ["PointComponent"],
+			blocklist: ["MoveComponent"]
+		});
+
+		const entity = world.createEntity("remove-test-1");
+		entity.addComponent(PointComponent, { x: 5, y: 5 });
+		eventSystem.processQueue();
+
+		let results = query.getResult();
+		expect(results.some(e => e.getID() === "remove-test-1")).toBeTruthy();
+
+		// Add a component from the blocklist - entity should be removed from query
+		entity.addComponent(MoveComponent, { dx: 1, dy: 1 });
+		eventSystem.processQueue();
+
+		results = query.getResult();
+		expect(results.some(e => e.getID() === "remove-test-1")).toBeFalsy();
+
+		query.dispose();
+	});
+
+	test("Query removes entity when entity is removed from world", () => {
+		const query = new Query({
+			allowlist: ["PointComponent"]
+		});
+
+		const entity = world.createEntity("remove-test-2");
+		entity.addComponent(PointComponent, { x: 3, y: 3 });
+		eventSystem.processQueue();
+
+		let results = query.getResult();
+		expect(results.some(e => e.getID() === "remove-test-2")).toBeTruthy();
+
+		// Remove entity from world - should trigger onEntityRemoved
+		world.unregisterEntity(entity);
+		eventSystem.processQueue();
+
+		results = query.getResult();
+		expect(results.some(e => e.getID() === "remove-test-2")).toBeFalsy();
+
+		query.dispose();
+	});
+
+	test("Query getSingleResult returns first entity or null", () => {
+		const query = new Query({
+			allowlist: ["PointComponent"],
+			blocklist: ["MoveComponent"]
+		});
+
+		eventSystem.processQueue();
+
+		// Should return first entity
+		const singleResult = query.getSingleResult();
+		expect(singleResult).not.toBeNull();
+		expect(singleResult?.getID()).toEqual("1337");
+
+		// Test with empty query
+		const emptyQuery = new Query({
+			allowlist: ["NonExistentComponent"]
+		});
+
+		const noResult = emptyQuery.getSingleResult();
+		expect(noResult).toBeNull();
+
+		query.dispose();
+		emptyQuery.dispose();
+	});
+
+	test("Query onEntityRemoved when entity is not in query (else branch)", () => {
+		// Create a query that only matches PointComponent
+		const query = new Query({
+			allowlist: ["PointComponent"]
+		});
+
+		// Create an entity that DOESN'T match the query
+		const entity = world.createEntity("non-matching-entity");
+		entity.addComponent(MoveComponent, { dx: 5, dy: 5 });
+		eventSystem.processQueue();
+
+		// Verify entity is NOT in the query
+		let results = query.getResult();
+		expect(results.some(e => e.getID() === "non-matching-entity")).toBeFalsy();
+
+		// Now remove the entity - this triggers onEntityRemoved
+		// Since entity is not in query, exists will be false
+		world.unregisterEntity(entity);
+		eventSystem.processQueue();
+
+		// Query should still not contain it (nothing should change)
+		results = query.getResult();
+		expect(results.some(e => e.getID() === "non-matching-entity")).toBeFalsy();
+
+		query.dispose();
+	});
 });

test/core/ecs/ReactiveSystem.spec.ts

@@ -0,0 +1,74 @@
+import { test, expect, suite, vi } from "vitest";
+import { ReactiveSystem } from "@/core/ecs/ReactiveSystem";
+import { Query } from "@/core/ecs/Query";
+import { ServiceRegistry } from "@/core/service/ServiceRegistry";
+import { EventSystem } from "@/core/events/EventSystem";
+import { UpdateSystem } from "@/core/ecs/UpdateSystem";
+import { Entity } from "@/core/ecs/Entity";
+
+suite("ReactiveSystem Test Suite", () => {
+	let entityChanged = false;
+
+	class TestReactiveSystem extends ReactiveSystem {
+		queries = {
+			query: new Query({
+				allowlist: [],
+				blocklist: []
+			})
+		};
+		
+		public initialize(): void {
+			this.eventSystem.subscribeOnce("entityChanged", () => {
+				entityChanged = true;
+			});
+		}
+	}
+
+	test("ReactiveSystem extends UpdateSystem and has eventSystem", () => {
+		const eventSystem = ServiceRegistry.get<EventSystem>(EventSystem);
+		const system = new TestReactiveSystem(0);
+
+		expect(system).toBeDefined();
+		expect(system.getPriority()).toBe(0);
+		expect(system.isEnabled()).toBeTruthy();
+		expect(system).toBeInstanceOf(UpdateSystem);
+
+		eventSystem.dispatch("entityChanged", {
+			entity: new Entity("1337")
+		});
+		eventSystem.processQueue();
+
+		expect(entityChanged).toBeTruthy();
+	});
+
+	test("ReactiveSystem execute method does nothing by default", () => {
+		const system = new TestReactiveSystem(0);
+		
+		// Execute should not throw and does nothing
+		expect(() => system.execute(16, 1)).not.toThrow();
+		
+		// Verify it was called (even though it does nothing)
+		const executeSpy = vi.spyOn(system, 'execute');
+		system.execute(16, 1);
+		expect(executeSpy).toHaveBeenCalledWith(16, 1);
+	});
+
+	test("ReactiveSystem can be enabled and disabled", () => {
+		const system = new TestReactiveSystem(5);
+
+		expect(system.isEnabled()).toBeTruthy();
+		
+		system.disable();
+		expect(system.isEnabled()).toBeFalsy();
+		
+		system.enable();
+		expect(system.isEnabled()).toBeTruthy();
+	});
+
+	test("ReactiveSystem can access queries", () => {
+		const system = new TestReactiveSystem(0);
+		
+		expect(system.queries).toBeDefined();
+		expect(system.queries.query).toBeInstanceOf(Query);
+	});
+});

test/core/ecs/System.spec.ts

@@ -1,6 +1,6 @@
 import { test, expect, suite } from "vitest";
-import { System } from "../../../src/core/ecs/System";
-import { Query } from "../../../src/core/ecs/Query";
+import { System } from "@/core/ecs/System";
+import { Query } from "@/core/ecs/Query";
 
 suite("System Test Suite", () => {
 	class MovementSystem extends System {