code improved

Author: Vladimir Enchev

lib/services/platform-service.ts

@@ -1,6 +1,7 @@
 ///<reference path="../.d.ts"/>
 "use strict";
 
+import * as child_process from "child_process";
 import * as path from "path";
 import * as shell from "shelljs";
 import * as constants from "../constants";
@@ -486,24 +487,18 @@ export class PlatformService implements IPlatformService {
 
 		if (this.$options.availableDevices) {
 			return (() => {
-				let exec = require("child_process").exec;
+				let callback = (error: Error, stdout: Buffer, stderr: Buffer) => {
+					if (error !== null) {
+						this.$errors.fail(error);
+					} else {
+						this.$logger.info(stdout);
+					}
+				};
 
 				if (this.$mobileHelper.isiOSPlatform(platform)) {
-					exec("instruments -s devices", (error: Error, stdout: string, stderr: string) => {
-						if (error !== null) {
-							this.$errors.fail(error);
-						} else {
-							this.$logger.info(stdout);
-						}
-					});
+					child_process.exec("instruments -s devices", callback);
 				} else if (this.$mobileHelper.isAndroidPlatform(platform)) {
-					exec("android list avd", (error: Error, stdout: string, stderr: string) => {
-						if (error !== null) {
-							this.$errors.fail(error);
-						} else {
-							this.$logger.info(stdout);
-						}
-					});
+					child_process.exec("android list avd", callback);
 				}
 			}).future<void>()();
 		} else {