chore: fix unit tests

Author: Fatme

test/services/preview-devices-service.ts

@@ -4,6 +4,7 @@ import { Device } from "nativescript-preview-sdk";
 import { assert } from "chai";
 import { DeviceDiscoveryEventNames } from "../../lib/common/constants";
 import { LoggerStub, ErrorsStub } from "../stubs";
+import * as sinon from "sinon";
 
 let foundDevices: Device[] = [];
 let lostDevices: Device[] = [];
@@ -40,6 +41,7 @@ function resetDevices() {
 describe("PreviewDevicesService", () => {
 	describe("onDevicesPresence", () => {
 		let previewDevicesService: IPreviewDevicesService = null;
+		let clock: sinon.SinonFakeTimers = null;
 		beforeEach(() => {
 			const injector = createTestInjector();
 			previewDevicesService = injector.resolve("previewDevicesService");
@@ -49,11 +51,13 @@ describe("PreviewDevicesService", () => {
 			previewDevicesService.on(DeviceDiscoveryEventNames.DEVICE_LOST, device => {
 				lostDevices.push(device);
 			});
+			clock = sinon.useFakeTimers();
 		});
 
 		afterEach(() => {
 			previewDevicesService.removeAllListeners();
 			resetDevices();
+			clock.restore();
 		});
 
 		it("should add new device", () => {
@@ -101,6 +105,7 @@ describe("PreviewDevicesService", () => {
 			resetDevices();
 
 			previewDevicesService.updateConnectedDevices([]);
+			clock.tick(5000);
 
 			assert.deepEqual(foundDevices, []);
 			assert.deepEqual(lostDevices, [device1]);
@@ -116,6 +121,7 @@ describe("PreviewDevicesService", () => {
 			resetDevices();
 
 			previewDevicesService.updateConnectedDevices([device2]);
+			clock.tick(5000);
 
 			assert.deepEqual(previewDevicesService.getConnectedDevices(), [device2]);
 			assert.deepEqual(foundDevices, [device2]);