Fix livesync for ios devices

Currently we are creating new instance of the AndroidLiveSyncService and IOSLiveSyncService. When `--watch` option is used, CLI gets new instance for each change of a file. This leads to opening new socket every single time. The second changed file leads to process exit as the inspector runtime logic is triggered many times.
Fix this by caching the instances per device.

Author: Mitko-Kerezov

lib/providers/livesync-provider.ts

@@ -12,13 +12,22 @@ export class LiveSyncProvider implements ILiveSyncProvider {
 
 	private static FAST_SYNC_FILE_EXTENSIONS = [".css", ".xml"];
 
+	private platformSpecificLiveSyncServicesCache: IDictionary<any> = {};
 	public get platformSpecificLiveSyncServices(): IDictionary<any> {
 		return {
 			android: (_device: Mobile.IDevice, $injector: IInjector): IPlatformLiveSyncService => {
-				return $injector.resolve(this.$androidLiveSyncServiceLocator.factory, {_device: _device});
+				if(!this.platformSpecificLiveSyncServicesCache[_device.deviceInfo.identifier]) {
+					this.platformSpecificLiveSyncServicesCache[_device.deviceInfo.identifier] = $injector.resolve(this.$androidLiveSyncServiceLocator.factory, {_device: _device});
+				}
+
+				return this.platformSpecificLiveSyncServicesCache[_device.deviceInfo.identifier];
 			},
 			ios: (_device: Mobile.IDevice, $injector: IInjector) => {
-				return $injector.resolve(this.$iosLiveSyncServiceLocator.factory, {_device: _device});
+				if(!this.platformSpecificLiveSyncServicesCache[_device.deviceInfo.identifier]) {
+					this.platformSpecificLiveSyncServicesCache[_device.deviceInfo.identifier] = $injector.resolve(this.$iosLiveSyncServiceLocator.factory, {_device: _device});
+				}
+
+				return this.platformSpecificLiveSyncServicesCache[_device.deviceInfo.identifier];
 			}
 		};
 	}

lib/services/livesync/ios-livesync-service.ts

@@ -9,13 +9,15 @@ let currentPageReloadId = 0;
 
 class IOSLiveSyncService extends liveSyncServiceBaseLib.LiveSyncServiceBase<Mobile.IiOSDevice> implements IPlatformLiveSyncService {
 	private static BACKEND_PORT = 18181;
+	private socket: net.Socket;
 
 	constructor(_device: Mobile.IDevice,
 		private $iOSSocketRequestExecutor: IiOSSocketRequestExecutor,
 		private $iOSNotification: IiOSNotification,
 		private $iOSEmulatorServices: Mobile.IiOSSimulatorService,
 		private $injector: IInjector,
-		private $logger: ILogger) {
+		private $logger: ILogger,
+		private $options: IOptions) {
 			super(_device);
 		}
 
@@ -34,36 +36,71 @@ class IOSLiveSyncService extends liveSyncServiceBaseLib.LiveSyncServiceBase<Mobi
 		return (() => {
 			let timeout = 9000;
 			if (this.device.isEmulator) {
-				helpers.connectEventually(() => net.connect(IOSLiveSyncService.BACKEND_PORT), (socket: net.Socket) => this.sendPageReloadMessage(socket));
+				if (!this.socket) {
+					helpers.connectEventually(() => net.connect(IOSLiveSyncService.BACKEND_PORT), (socket: net.Socket) => {
+						this.socket = socket;
+						if(this.$options.watch) {
+							this.attachProcessExitHandlers();
+						}
+						this.sendPageReloadMessage();
+					});
+				} else {
+					this.sendPageReloadMessage();
+				}
 			 	this.$iOSEmulatorServices.postDarwinNotification(this.$iOSNotification.attachRequest).wait();
 			} else {
 				this.$iOSSocketRequestExecutor.executeAttachRequest(this.device, timeout).wait();
-				let socket = this.device.connectToPort(IOSLiveSyncService.BACKEND_PORT);
-				this.sendPageReloadMessage(socket);
+				this.socket = this.device.connectToPort(IOSLiveSyncService.BACKEND_PORT);
+				this.sendPageReloadMessage();
 			}
 		}).future<void>()();
 	}
 
-	private sendPageReloadMessage(socket: net.Socket): void {
+	private sendPageReloadMessage(): void {
 		try {
-			this.sendPageReloadMessageCore(socket);
-			socket.once("data", (data: NodeBuffer|string) => {
+			this.sendPageReloadMessageCore();
+			this.socket.on("data", (data: NodeBuffer|string) => {
 				this.$logger.trace(`Socket sent data: ${data.toString()}`);
-				socket.destroy();
+				this.destroySocketIfNecessary();
 			});
 		} catch(err) {
 			this.$logger.trace("Error while sending page reload:", err);
-			socket.destroy();
+			this.destroySocketIfNecessary();
 		}
 	}
 
-	private sendPageReloadMessageCore(socket: net.Socket): void {
+	private sendPageReloadMessageCore(): void {
 		let message = `{ "method":"Page.reload","params":{"ignoreCache":false},"id":${++currentPageReloadId} }`;
 		let length = Buffer.byteLength(message, "utf16le");
 		let payload = new Buffer(length + 4);
 		payload.writeInt32BE(length, 0);
 		payload.write(message, 4, length, "utf16le");
-		socket.write(payload);
+		this.socket.write(payload);
+	}
+
+	private attachProcessExitHandlers(): void {
+		process.on("exit", (exitCode: number) => {
+			this.destroySocket();
+		});
+
+		process.on("SIGTERM", () => {
+			this.destroySocket();
+		});
+
+		process.on("SIGINT", () => {
+			this.destroySocket();
+		});
+	}
+
+	private destroySocketIfNecessary(): void {
+		if(!this.$options.watch) {
+			this.destroySocket();
+		}
+	}
+
+	private destroySocket(): void {
+		this.socket.destroy();
+		this.socket = null;
 	}
 }
 $injector.register("iosLiveSyncServiceLocator", {factory: IOSLiveSyncService});