Init

extensions/amp-carousel/0.1/slidescroll.js

@@ -686,7 +686,10 @@ export class AmpSlideScroll extends BaseSlides {
    */
   showSlide_(newIndex) {
     const {noOfSlides_} = this;
-    newIndex = dev().assertNumber(newIndex);
+    if (isNaN(newIndex)) {
+      dev().error('Attempted to show slide that is not a number');
+      return;
+    }
     if (
       newIndex < 0 ||
       newIndex >= noOfSlides_ ||

extensions/amp-carousel/0.1/test/test-slidescroll.js

@@ -23,7 +23,7 @@ import {
   whenUpgradedToCustomElement,
 } from '../../../../src/dom';
 import {installResizeObserverStub} from '../../../../testing/resize-observer-stub';
-import {user} from '../../../../src/log';
+import {dev, user} from '../../../../src/log';
 
 describes.realWin(
   'SlideScroll',
@@ -1271,6 +1271,25 @@ describes.realWin(
         expect(showSlideSpy).to.have.been.calledWith(4);
       });
 
+      it('should error on a non-number goToSlide', async () => {
+        const ampSlideScroll = await getAmpSlideScroll(true);
+        const impl = await ampSlideScroll.getImpl();
+        const devErrorSpy = env.sandbox.spy(dev(), 'error');
+
+        impl.showSlideAndTriggerAction_(NaN)
+        expect(devErrorSpy).to.be.calledOnce;
+        expect(devErrorSpy.args[0][0]).to.match(/Attempted to show slide that is not a number/);
+      });
+
+      it('should return false for invalid slide number', async () => {
+        const ampSlideScroll = await getAmpSlideScroll(true);
+        const impl = await ampSlideScroll.getImpl();
+
+        impl.noOfSlides_ = 10;
+        expect(impl.showSlide_(Infinity)).to.be.false;
+        expect(impl.showSlide_(-Infinity)).to.be.false;
+      });
+
       it('should NOT call showSlide_ before layout', async () => {
         const ampSlideScroll = await getAmpSlideScroll(
           true,