🐛 Subscriptions: Stops stopping propagation of click events (ampproject#26702)

* Stops stopping propagation of click events

* Add test

* Creates const and uses array accessor for surrogate property on click events

Author: ChrisAntaki

extensions/amp-subscriptions/0.1/local-subscription-platform-base.js

@@ -21,6 +21,12 @@ import {UrlBuilder} from './url-builder';
 import {closestAncestorElementBySelector} from '../../../src/dom';
 import {dev, userAssert} from '../../../src/log';
 
+/**
+ * Surrogate property added to click events marking them as handled by the
+ * amp-subscriptions extension.
+ */
+const CLICK_HANDLED_EVENT_PROPERTY = '_AMP_SUBSCRIPTIONS_CLICK_HANDLED';
+
 /**
  * This implements the methods to interact with various subscription platforms.
  *
@@ -109,27 +115,24 @@ export class LocalSubscriptionBasePlatform {
    * @protected
    */
   initializeListeners_() {
-    const handleClickAndStopEventPropagation = e => {
-      e.stopPropagation();
+    const handleClickOncePerEvent = e => {
+      if (e[CLICK_HANDLED_EVENT_PROPERTY]) {
+        return;
+      }
+      e[CLICK_HANDLED_EVENT_PROPERTY] = true;
 
       const element = closestAncestorElementBySelector(
         dev().assertElement(e.target),
         '[subscriptions-action]'
       );
       this.handleClick_(element);
     };
-    this.rootNode_.addEventListener(
-      'click',
-      handleClickAndStopEventPropagation
-    );
+    this.rootNode_.addEventListener('click', handleClickOncePerEvent);
 
     // If the root node has a `body` property, listen to events on that too,
     // to fix an iOS shadow DOM bug (https://github.com/ampproject/amphtml/issues/25754).
     if (this.rootNode_.body) {
-      this.rootNode_.body.addEventListener(
-        'click',
-        handleClickAndStopEventPropagation
-      );
+      this.rootNode_.body.addEventListener('click', handleClickOncePerEvent);
     }
   }
 

extensions/amp-subscriptions/0.1/test/test-local-subscriptions.js

@@ -116,6 +116,17 @@ describes.fakeWin('LocalSubscriptionsPlatform', {amp: true}, env => {
     expect(domStub.getCall(0).args[0]).to.be.equals('click');
   });
 
+  it('initializeListeners_ should handle clicks once per event', () => {
+    const handleClickStub = env.sandbox.stub(
+      localSubscriptionPlatform,
+      'handleClick_'
+    );
+
+    localSubscriptionPlatform.initializeListeners_();
+    localSubscriptionPlatform.rootNode_.body.click();
+    expect(handleClickStub).calledOnce;
+  });
+
   it('should return baseScore', () => {
     expect(localSubscriptionPlatform.getBaseScore()).to.be.equal(99);
   });