test(action): ✅ add simple focus up action unit test

This is just a basic unit test.

src/controller/action.test.ts

@@ -0,0 +1,25 @@
+// SPDX-FileCopyrightText: 2021 Mikhail Zolotukhin <mail@genda.life>
+//
+// SPDX-License-Identifier: MIT
+
+import { createMock } from "ts-auto-mock";
+import { Engine } from "../engine";
+import { FocusUpperWindow } from "./action";
+
+describe("action", () => {
+  describe("focus up", () => {
+    const fakeEngine = createMock<Engine>({ focusDir: jest.fn() });
+    const action = new FocusUpperWindow(fakeEngine);
+    it("correctly executes", () => {
+      // Arrange
+      jest.spyOn(fakeEngine, "focusDir");
+
+      // Act
+      action.execute();
+
+      // Assert
+      // eslint-disable-next-line @typescript-eslint/unbound-method
+      expect(fakeEngine.focusDir).toBeCalledWith("up");
+    });
+  });
+});