modify: fix test and logic

browser/lib/date-formatter.js

@@ -1,36 +1,18 @@
 /**
  * @fileoverview Formatting date string.
  */
-
-/** @var {Array} */
-const monthMapings = [
-  'Jan.', 'Feb.', 'Mar.', 'Apr.', 'May', 'Jun.',
-  'Jul.', 'Aug.', 'Sep.', 'Oct.', 'Nov.', 'Dec.',
-];
+import moment from 'moment';
 
 /**
  * @description Return date string. For example, 'Sep.9, 2016 12:00'.
- * @param {Date}
+ * @param {mixed}
  * @return {string}
  */
 export function getLastUpdated(date) {
-  if (!(date instanceof Date)) {
-    throw Error('Invalid argument. Only instance of Date Object');
+  const m = moment(date)
+  if (!m.isValid()) {
+    throw Error('Invalid argument.');
   }
 
-  const year = date.getFullYear();
-  const month = monthMapings[date.getMonth()];
-  const day = date.getDate();
-  let hour = date.getHours();
-  let minute = date.getMinutes();
-
-  if (hour < 10) {
-    hour = `0${hour}`;
-  }
-
-  if (minute < 10) {
-    minute = `0${minute}`;
-  }
-
-  return `${month}${day}, ${year} ${hour}:${minute}`;
+  return m.format('MMM D, gggg H:mm')
 }