Add nav_source param to navbar clicks

- bind events when snowplow is enabled
- rename snowPlowEnabled to snowplowEnabled

ee/app/assets/javascripts/event_tracking/navbar.js

 import Stats from 'ee/stats';
+import { mergeUrlParams } from '~/lib/utils/url_utility';
 
 export default function trackNavbarEvents() {
   const container = '.navbar-gitlab';
   const category = 'navbar_top';
+  const navbar = document.querySelector('.navbar-gitlab');
+
+  /**
+   * intercepts clicks on navbar links
+   * and adds the 'nav_source=navbar' query parameter
+   */
+  const appendLinkParam = e => {
+    const NAVSOURCE_KEY = 'nav_source';
+    const NAVSOURCE_VALUE = 'navbar';
+    const target = e.target || e.srcElement;
+
+    // get closest link in case the target is a wrapping DOM node
+    const link = target.tagName === 'A' ? target : target.closest('a');
+
+    if (link && link.href && link.href.indexOf(`${NAVSOURCE_KEY}=${NAVSOURCE_VALUE}`) === -1) {
+      const url = mergeUrlParams({ [NAVSOURCE_KEY]: NAVSOURCE_VALUE }, link.href);
+      link.setAttribute('href', url);
+    }
+  };
 
   Stats.bindTrackableContainer(container, category);
 
-  // track search inputs within frequent-items component
-  document
-    .querySelectorAll(`${container} .frequent-items-dropdown-container input`)
-    .forEach(element => {
-      element.addEventListener('click', e => {
-        const target = e.currentTarget;
-        const parentDropdown = target.closest('li.dropdown');
-        const label = `${parentDropdown.getAttribute('data-track-label')}_search`;
+  if (Stats.snowplowEnabled) {
+    // track search inputs within frequent-items component
+    document
+      .querySelectorAll(`${container} .frequent-items-dropdown-container input`)
+      .forEach(element => {
+        element.addEventListener('click', e => {
+          const target = e.currentTarget;
+          const parentDropdown = target.closest('li.dropdown');
+          const label = `${parentDropdown.getAttribute('data-track-label')}_search`;
 
-        Stats.trackEvent(category, 'activate_form_input', { label, property: '', value: '' });
+          Stats.trackEvent(category, 'activate_form_input', { label, property: '', value: '' });
+        });
       });
-    });
+
+    if (navbar) {
+      navbar.addEventListener('click', appendLinkParam);
+      navbar.addEventListener('contextmenu', appendLinkParam);
+    }
+  }
 }

ee/app/assets/javascripts/stats.js

 import $ from 'jquery';
 
-const snowPlowEnabled = () => typeof window.snowplow === 'function';
+const snowplowEnabled = () => typeof window.snowplow === 'function';
 
 const trackEvent = (
   category,
   eventName,
   additionalData = { label: '', property: '', value: '' },
 ) => {
-  if (!snowPlowEnabled()) {
+  if (!snowplowEnabled()) {
     return;
   }
 
@@ -33,7 +33,7 @@ const isBsDropdown = element => {
 };
 
 const bindTrackableContainer = (container = '', category = document.body.dataset.page) => {
-  if (!snowPlowEnabled()) {
+  if (!snowplowEnabled()) {
     return;
   }
 
@@ -92,6 +92,7 @@ const bindTrackableContainer = (container = '', category = document.body.dataset
 };
 
 export default {
+  snowplowEnabled,
   trackEvent,
   bindTrackableContainer,
 };

ee/changelogs/unreleased/8808-tracking-navbar-links-not-behind-dropdowns-in-snowplow.yml

+---
+title: Track navbar links in Snowplow
+merge_request: 9059
+author:
+type: other