[Improvement] add utils test cases (#380)

packages/utils/index.js

@@ -19,9 +19,10 @@ export function get(object, path) {
 
 const camelizeRE = /-(\w)/g;
 export function camelize(str) {
-  return str.replace(camelizeRE, (_, c) => c ? c.toUpperCase() : '');
+  return str.replace(camelizeRE, (_, c) => c.toUpperCase());
 }
 
 export function isAndroid() {
+  /* istanbul ignore next */
   return isServer ? false : /android/.test(navigator.userAgent.toLowerCase());
 }

packages/utils/raf.js

@@ -5,6 +5,8 @@
 import { isServer } from './index';
 
 let prev = Date.now();
+
+/* istanbul ignore next */
 function fallback(fn) {
   const curr = Date.now();
   const ms = Math.max(0, 16 - (curr - prev));
@@ -13,11 +15,16 @@ function fallback(fn) {
   return id;
 }
 
+/* istanbul ignore next */
 const global = isServer ? global : window;
+
+/* istanbul ignore next */
 const iRaf =
   global.requestAnimationFrame ||
   global.webkitRequestAnimationFrame ||
   fallback;
+
+/* istanbul ignore next */
 const iCancel =
   global.cancelAnimationFrame ||
   global.webkitCancelAnimationFrame ||