Added logic to delay resize requests to be made after an invalid requ…

…est is made until 500ms passes (#35603)

* added fixed and nit tests

* Fixed a few issues: made a variable private

* rebuilding as buidl was failing

extensions/amp-ad/0.1/amp-ad-xorigin-iframe-handler.js

@@ -44,6 +44,9 @@ const MIN_INABOX_POSITION_EVENT_INTERVAL = 100;
 /** @type {string} */
 const TAG = 'amp-ad-xorigin-iframe';
 
+/** @type {number} */
+const MSEC_REPEATED_REQUEST_DELAY = 500;
+
 export class AmpAdXOriginIframeHandler {
   /**
    * @param {!./amp-ad-3p-impl.AmpAd3PImpl|!../../amp-a4a/0.1/amp-a4a.AmpA4A} baseInstance
@@ -64,6 +67,15 @@ export class AmpAdXOriginIframeHandler {
     /** @type {?HTMLIFrameElement} iframe instance */
     this.iframe = null;
 
+    /* This variable keeps keeps track when an invalid resize request is made, and
+     * is associated with each iframe. If the request is invalid, then a new request
+     * cannot be made until a certain amount of time has passed, 500 ms by default
+     * (see MSEC_REPEATED_REQUEST_DELAY). Once the timer has cooled down,
+     * a new request can be made.
+     */
+    /** @private {number} */
+    this.lastRejectedResizeTime_ = 0;
+
     /** @private {?LegacyAdIntersectionObserverHost} */
     this.legacyIntersectionObserverApiHost_ = null;
 
@@ -170,14 +182,29 @@ export class AmpAdXOriginIframeHandler {
           if (!!data['hasOverflow']) {
             this.element_.warnOnMissingOverflow = false;
           }
-          this.handleResize_(
-            data['id'],
-            data['height'],
-            data['width'],
-            source,
-            origin,
-            event
-          );
+          if (
+            Date.now() - this.lastRejectedResizeTime_ >=
+            MSEC_REPEATED_REQUEST_DELAY
+          ) {
+            this.handleResize_(
+              data['id'],
+              data['height'],
+              data['width'],
+              source,
+              origin,
+              event
+            );
+          } else {
+            // need to wait 500ms until next resize request is allowed.
+            this.sendEmbedSizeResponse_(
+              false,
+              data['id'],
+              data['width'],
+              data['height'],
+              source,
+              origin
+            );
+          }
         },
         true,
         true
@@ -455,6 +482,12 @@ export class AmpAdXOriginIframeHandler {
         .updateSize(height, width, iframeHeight, iframeWidth, event)
         .then(
           (info) => {
+            if (!info.success) {
+              // invalid request parameters, disable requests for 500ms
+              this.lastRejectedResizeTime_ = Date.now();
+            } else {
+              this.lastRejectedResizeTime_ = 0;
+            }
             this.uiHandler_.onResizeSuccess();
             this.sendEmbedSizeResponse_(
               info.success,

extensions/amp-ad/0.1/test/test-amp-ad-xorigin-iframe-handler.js

@@ -30,6 +30,7 @@ describes.sandboxed('amp-ad-xorigin-iframe-handler', {}, (env) => {
   let renderStartedSpy;
   let iframeHandler;
   let iframe;
+  let clock;
   let testIndex = 0;
 
   beforeEach(() => {
@@ -338,6 +339,105 @@ describes.sandboxed('amp-ad-xorigin-iframe-handler', {}, (env) => {
         });
     });
 
+    describe('request valid and invalid ad resize useing embed-size API', async () => {
+      beforeEach(async () => {
+        clock = env.sandbox.useFakeTimers();
+        const updateSizeWrapper = env.sandbox.stub(
+          adImpl.uiHandler,
+          'updateSize'
+        );
+
+        updateSizeWrapper.resolves({
+          success: false,
+          newWidth: 114,
+          newHeight: 217,
+        });
+
+        // expect to fail, first call invalid request
+        iframe.postMessageToParent({
+          width: 114,
+          height: 217,
+          type: 'embed-size',
+          sentinel: 'amp3ptest' + testIndex,
+        });
+
+        const data = await iframe.expectMessageFromParent('embed-size-denied');
+
+        expect(data).to.jsonEqual({
+          requestedWidth: 114,
+          requestedHeight: 217,
+          type: 'embed-size-denied',
+          sentinel: 'amp3ptest' + testIndex,
+        });
+
+        updateSizeWrapper.resolves({
+          success: true,
+          newWidth: 114,
+          newHeight: 217,
+        });
+
+        // expect to fail invalid request right before 500ms
+        iframe.postMessageToParent({
+          width: 120,
+          height: 217,
+          type: 'embed-size',
+          sentinel: 'amp3ptest' + testIndex,
+        });
+
+        const data2 = await iframe.expectMessageFromParent('embed-size-denied');
+
+        expect(data2).to.jsonEqual({
+          requestedWidth: 120,
+          requestedHeight: 217,
+          type: 'embed-size-denied',
+          sentinel: 'amp3ptest' + testIndex,
+        });
+      });
+
+      it('should be able to use embed-size API, change size deny repeated attempts, but then denies valid attempt before 500ms delay', async () => {
+        // expect to fail, valid request, but called before 500ms
+        clock.tick(250);
+
+        iframe.postMessageToParent({
+          width: 114,
+          height: 217,
+          type: 'embed-size',
+          sentinel: 'amp3ptest' + testIndex,
+        });
+
+        const data3 = await iframe.expectMessageFromParent('embed-size-denied');
+        expect(data3).to.jsonEqual({
+          requestedWidth: 114,
+          requestedHeight: 217,
+          type: 'embed-size-denied',
+          sentinel: 'amp3ptest' + testIndex,
+        });
+      });
+
+      it('should be able to use embed-size API, change size deny repeated attempts, but then works after 500ms delay', async () => {
+        // expect to succeed: valid request right after 500ms
+        clock.tick(500);
+
+        iframe.postMessageToParent({
+          width: 114,
+          height: 217,
+          type: 'embed-size',
+          sentinel: 'amp3ptest' + testIndex,
+        });
+
+        const data3 = await iframe.expectMessageFromParent(
+          'embed-size-changed'
+        );
+
+        expect(data3).to.jsonEqual({
+          requestedWidth: 114,
+          requestedHeight: 217,
+          type: 'embed-size-changed',
+          sentinel: 'amp3ptest' + testIndex,
+        });
+      });
+    });
+
     it('should be able to use embed-size API, change size succeed', () => {
       env.sandbox.stub(adImpl.uiHandler, 'updateSize').callsFake(() => {
         return Promise.resolve({