fix: validate params passed to preview command

Author: Fatme

lib/commands/preview.ts

@@ -3,6 +3,7 @@ export class PreviewCommand implements ICommand {
 	private static MIN_SUPPORTED_WEBPACK_VERSION = "0.17.0";
 
 	constructor(private $bundleValidatorHelper: IBundleValidatorHelper,
+		private $errors: IErrors,
 		private $liveSyncService: ILiveSyncService,
 		private $networkConnectivityValidator: INetworkConnectivityValidator,
 		private $projectData: IProjectData,
@@ -27,6 +28,10 @@ export class PreviewCommand implements ICommand {
 	}
 
 	public async canExecute(args: string[]): Promise<boolean> {
+		if (args && args.length) {
+			this.$errors.fail(`The arguments '${args.join(" ")}' are not valid for the preview command.`);
+		}
+
 		await this.$networkConnectivityValidator.validate();
 		this.$bundleValidatorHelper.validate(PreviewCommand.MIN_SUPPORTED_WEBPACK_VERSION);
 		return true;