added tests for main game loop

test/main.test.ts

@@ -0,0 +1,25 @@
+import {assert} from "chai";
+import {loop} from "../src/main";
+import {Game, Memory} from "./mock"
+
+describe("main", () => {
+  before(() => {
+    // runs before all test in this block
+  });
+
+  beforeEach(() => {
+    // runs before each test in this block
+    // @ts-ignore : allow adding Game to global
+    global.Game = _.clone(Game);
+    // @ts-ignore : allow adding Memory to global
+    global.Memory = _.clone(Memory);
+  });
+
+  it("should export a loop function", () => {
+    assert.isTrue(typeof loop === "function");
+  });
+
+  it("should return void when called with no context", () => {
+    assert.isUndefined(loop());
+  });
+});