Fixed Linting Error + Error with Line Highlighter found in Test

app/assets/javascripts/line_highlighter.js

@@ -56,7 +56,7 @@ LineHighlighter.prototype.bindEvents = function() {
 
 LineHighlighter.prototype.highlightHash = function(newHash) {
   let range;
-  if (newHash) this._hash = newHash;
+  if (newHash && typeof newHash === 'string') this._hash = newHash;
 
   this.clearHighlight();
 

app/assets/javascripts/repo/components/repo_preview.vue

@@ -28,8 +28,8 @@ export default {
         this.highlightFile();
       });
     },
-    activeLine(e) {
-      this.lineHighlighter.highlightHash('#L' + Store.activeLine);
+    activeLine() {
+      this.lineHighlighter.highlightHash(`#L${Store.activeLine}`);
     },
   },
 };