fix: enforce 3 seconds between app restarts in order to avoid frozen simulators on fast restarts

Author: DimitarTachev

lib/declarations.ts

@@ -1,6 +1,21 @@
 ///<reference path="./.d.ts"/>
 "use strict";
 
+
+interface IDictionary<T> {
+	[key: string]: T
+}
+
+interface IDeferPromise<T> {
+	isRejected(): boolean;
+	isPending(): boolean;
+	getResult(): any;
+	promise: Promise<T>;
+	resolve(value?: T | PromiseLike<T>): void;
+	reject(reason?: any): void;
+	isResolved(): boolean;
+}
+
 interface IiPhoneSimulator {
 	run(applicationPath: string, applicationIdentifier: string, options: IOptions): Promise<string>;
 	printDeviceTypes(): Promise<void>;
@@ -42,10 +57,6 @@ interface ISimctl {
 	getAppContainer(deviceId: string, applicationIdentifier: string): Promise<string>;
 }
 
-interface IDictionary<T> {
-	[key: string]: T;
-}
-
 interface ISimulator extends INameGetter {
 	getDevices(): Promise<IDevice[]>;
 	getSdks(): Promise<ISdk[]>;

lib/iphone-simulator-xcode-simctl.ts

@@ -85,7 +85,25 @@ export class XCodeSimctlSimulator extends IPhoneSimulatorNameGetter implements I
 		return this.simctl.uninstall(deviceId, appIdentifier, { skipError: true });
 	}
 
+	private static startingApps: IDictionary<Promise<string>> = {};
+	private static stoppingApps: IDictionary<Promise<void>> = {};
+
 	public async startApplication(deviceId: string, appIdentifier: string, options: IOptions): Promise<string> {
+		const startingAppKey: string = deviceId + appIdentifier;
+		if (XCodeSimctlSimulator.startingApps[startingAppKey]) {
+			return XCodeSimctlSimulator.startingApps[startingAppKey];
+		}
+
+		const deferPromise = utils.deferPromise<string>();
+		XCodeSimctlSimulator.startingApps[startingAppKey] = deferPromise.promise;
+		// let the app start for 3 seconds in order to avoid a frozen simulator
+		// when the app is killed on splash screen
+		setTimeout(() => {
+			delete XCodeSimctlSimulator.startingApps[startingAppKey];
+			deferPromise.resolve();
+		}, 3000);
+
+
 		// simctl launch command does not launch the process immediately and we have to wait a little bit,
 		// just to ensure all related processes and services are alive.
 		const launchResult = await this.simctl.launch(deviceId, appIdentifier, options);
@@ -94,6 +112,18 @@ export class XCodeSimctlSimulator extends IPhoneSimulatorNameGetter implements I
 	}
 
 	public async stopApplication(deviceId: string, appIdentifier: string, bundleExecutable: string): Promise<void> {
+		const appKey: string = deviceId + appIdentifier;
+		if (XCodeSimctlSimulator.stoppingApps[appKey]) {
+			return XCodeSimctlSimulator.stoppingApps[appKey];
+		}
+
+		const deferPromise = utils.deferPromise<void>();
+		XCodeSimctlSimulator.stoppingApps[appKey] = deferPromise.promise;
+
+		if (XCodeSimctlSimulator.startingApps[appKey]) {
+			await XCodeSimctlSimulator.startingApps[appKey];
+		}
+
 		try {
 			let pid = this.getPid(deviceId, bundleExecutable);
 			while (pid) {
@@ -108,6 +138,11 @@ export class XCodeSimctlSimulator extends IPhoneSimulatorNameGetter implements I
 
 		await this.simctl.terminate(deviceId, appIdentifier);
 		utils.sleep(0.5);
+		
+		delete XCodeSimctlSimulator.stoppingApps[appKey];
+		deferPromise.resolve();
+
+		return deferPromise.promise;
 	}
 
 	private getPid(deviceId: string, bundleExecutable: string): string {

lib/utils.ts

@@ -13,3 +13,37 @@ export function getCurrentEpochTime(): number {
 export function sleep(seconds: number): void {
 	childProcess.execSync(`sleep ${seconds}`);
 }
+
+export function deferPromise<T>(): IDeferPromise<T> {
+	let resolve: (value?: T | PromiseLike<T>) => void;
+	let reject: (reason?: any) => void;
+	let isResolved = false;
+	let isRejected = false;
+	let promise: Promise<T>;
+	let result: T | PromiseLike<T>;
+
+	promise = new Promise<T>((innerResolve, innerReject) => {
+		resolve = (value?: T | PromiseLike<T>) => {
+			isResolved = true;
+			result = value;
+
+			return innerResolve(value);
+		};
+
+		reject = (reason?: any) => {
+			isRejected = true;
+
+			return innerReject(reason);
+		};
+	});
+
+	return {
+		promise,
+		resolve,
+		reject,
+		isResolved: () => isResolved,
+		isRejected: () => isRejected,
+		isPending: () => !isResolved && !isRejected,
+		getResult: () => result
+	};
+}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ios-sim-portable",
-  "version": "4.0.9",
+  "version": "4.1.0",
   "description": "",
   "main": "./lib/ios-sim.js",
   "scripts": {