[skip ci] refactor function parameters

app/assets/javascripts/users_select.js

@@ -279,7 +279,12 @@ import Vue from 'vue';
                   });
                 } else if (isActive) {
                   // user selected
-                  gl.sidebarAssigneesOptions.assignees.addUser(user.id, user.name, user.username, user.avatar_url);
+                  gl.sidebarAssigneesOptions.assignees.addUser({
+                    id: user.id,
+                    name: user.name,
+                    username: user.username,
+                    avatarUrl: user.avatar_url
+                  });
 
                   // Remove unassigned selection (if it was previously selected)
                   const unassignedSelected = $dropdown.closest('.selectbox')

app/assets/javascripts/vue_sidebar_assignees/stores/sidebar_assignees_store.js

@@ -12,7 +12,9 @@ export default class SidebarAssigneesStore {
     this.editable = editable;
   }
 
-  addUser(id, name = '', username = '', avatarUrl = '', saved = false) {
+  addUser(user, saved = false) {
+    const { id, name, username, avatarUrl } = user;
+
     this.users.push({
       id,
       name,

app/views/shared/issuable/_sidebar.html.haml

@@ -217,7 +217,12 @@
       - issuable.assignees.each do |assignee|
         :javascript
           document.addEventListener('DOMContentLoaded', () => {
-            gl.sidebarAssigneesOptions.assignees.addUser(parseInt("#{assignee.id}", 10), "#{assignee.name}", "#{assignee.username}", "#{assignee.avatar_url}", true);
+            gl.sidebarAssigneesOptions.assignees.addUser({
+              id: parseInt("#{assignee.id}", 10),
+              name: "#{assignee.name}",
+              username: "#{assignee.username}",
+              avatarUrl: "#{assignee.avatar_url}"
+            }, true);
           });
 
     :javascript