Convert common time helpers to Typescript (#2391)

js/src/common/helpers/fullTime.js → js/src/common/helpers/fullTime.tsx

@@ -1,11 +1,11 @@
+import dayjs from 'dayjs';
+import * as Mithril from 'mithril';
+
 /**
  * The `fullTime` helper displays a formatted time string wrapped in a <time>
  * tag.
- *
- * @param {Date} time
- * @return {Object}
  */
-export default function fullTime(time) {
+export default function fullTime(time: Date): Mithril.Vnode {
   const d = dayjs(time);
 
   const datetime = d.format();

js/src/common/helpers/humanTime.js → js/src/common/helpers/humanTime.tsx

@@ -1,14 +1,13 @@
+import dayjs from 'dayjs';
+import * as Mithril from 'mithril';
 import humanTimeUtil from '../utils/humanTime';
 
 /**
  * The `humanTime` helper displays a time in a human-friendly time-ago format
  * (e.g. '12 days ago'), wrapped in a <time> tag with other information about
  * the time.
- *
- * @param {Date} time
- * @return {Object}
  */
-export default function humanTime(time) {
+export default function humanTime(time: Date): Mithril.Vnode {
   const d = dayjs(time);
 
   const datetime = d.format();

js/src/common/utils/humanTime.ts

@@ -1,3 +1,6 @@
+import dayjs from 'dayjs';
+import 'dayjs/plugin/relativeTime';
+
 /**
  * The `humanTime` utility converts a date to a localized, human-readable time-
  * ago string.