DEV: Minor code improvements.

app/assets/javascripts/discourse/lib/keyboard-shortcuts.js.es6

@@ -76,6 +76,8 @@ const bindings = {
   "x t": { click: "#dismiss-topics,#dismiss-topics-top" } // dismiss topics
 };
 
+const animationDuration = 100;
+
 export default {
   bindEvents(keyTrapper, container) {
     this.keyTrapper = keyTrapper;
@@ -420,7 +422,8 @@ export default {
     // Pressing a move key (J/K) very quick (i.e. keeping J or K pressed) will
     // move fast by disabling smooth page scrolling.
     const now = +new Date();
-    const fast = this._lastMoveTime && now - this._lastMoveTime < 150;
+    const fast =
+      this._lastMoveTime && now - this._lastMoveTime < 1.5 * animationDuration;
     this._lastMoveTime = now;
 
     const $articles = this._findArticles();
@@ -446,14 +449,9 @@ export default {
     const index = $articles.index($selected);
     let $article = $articles.eq(index);
 
-    /*
-     * Try doing a page scroll in the context of current post.
-     */
-
+    // Try doing a page scroll in the context of current post.
     if (!fast && direction !== 0 && $article.length > 0) {
-      /** @var Begin and end offsets for current article
-       *       The beginning of first article is the beginning of the page.
-       */
+      // The beginning of first article is the beginning of the page.
       const beginArticle =
         $article.is(".topic-post") && $article.find("#post_1").length
           ? 0
@@ -461,7 +459,6 @@ export default {
       const endArticle =
         $article.offset().top + $article[0].getBoundingClientRect().height;
 
-      /** @var Begin and end offsets for screen */
       const beginScreen = $(window).scrollTop();
       const endScreen = beginScreen + window.innerHeight;
 
@@ -482,10 +479,7 @@ export default {
       }
     }
 
-    /*
-     * Try scrolling to post above or below.
-     */
-
+    // Try scrolling to post above or below.
     if ($selected.length !== 0) {
       if (direction === -1 && index === 0) return;
       if (direction === 1 && index === $articles.length - 1) return;
@@ -512,9 +506,7 @@ export default {
         );
       }
 
-      /*
-       * Otherwise scroll through the suggested topic list.
-       */
+      // Otherwise scroll through the suggested topic list.
       this._scrollList($article, direction);
     }
   },
@@ -522,7 +514,7 @@ export default {
   _scrollTo(scrollTop, complete) {
     $("html, body")
       .stop(true, true)
-      .animate({ scrollTop }, { duration: 100, complete });
+      .animate({ scrollTop }, { duration: animationDuration, complete });
   },
 
   _scrollList($article) {
@@ -554,7 +546,7 @@ export default {
     }
     this._scrollAnimation = $("html, body").animate(
       { scrollTop: scrollPos + "px" },
-      100
+      animationDuration
     );
   },