move device discovery to debug command as it is done for run command (NativeScript#3008)

* move device discovery to debug command as it is done for run command

* update after review

Author: Plamen5kov

lib/commands/debug.ts

@@ -37,6 +37,8 @@ export class DebugPlatformCommand implements ICommand {
 
 		const selectedDeviceForDebug = await this.getDeviceForDebug();
 
+		await this.$devicesService.detectCurrentlyAttachedDevices({ shouldReturnImmediateResult: false, platform: this.platform });
+
 		await this.$liveSyncCommandHelper.executeLiveSyncOperation([selectedDeviceForDebug], this.$debugLiveSyncService, this.platform);
 	}
 

lib/definitions/livesync.d.ts

@@ -267,6 +267,13 @@ interface IDevicePathProvider {
 }
 
 interface ILiveSyncCommandHelper {
+	/**
+	 * Method sets up configuration, before calling livesync and expects that devices are already discovered.
+	 * @param {Mobile.IDevice[]} devices List of discovered devices
+	 * @param {ILiveSyncService} liveSyncService Service expected to do the actual livesyncing
+	 * @param {string} platform The platform for which the livesync will be ran
+	 * @returns {Promise<void>}
+	 */
 	executeLiveSyncOperation(devices: Mobile.IDevice[], liveSyncService: ILiveSyncService, platform: string): Promise<void>;
 	getPlatformsForOperation(platform: string): string[];
 }

lib/services/livesync/livesync-command-helper.ts

@@ -20,8 +20,6 @@ export class LiveSyncCommandHelper implements ILiveSyncCommandHelper {
 			this.$errors.failWithoutHelp("Unable to find applicable devices to execute operation and unable to start emulator when platform is not specified.");
 		}
 
-		await this.$devicesService.detectCurrentlyAttachedDevices({ shouldReturnImmediateResult: false, platform });
-
 		const workingWithiOSDevices = !platform || this.$mobileHelper.isiOSPlatform(platform);
 		const shouldKeepProcessAlive = this.$options.watch || !this.$options.justlaunch;
 		if (workingWithiOSDevices && shouldKeepProcessAlive) {