From c4cb5971870e0bdce63a0a26b7dac2c6d8a1a448 Mon Sep 17 00:00:00 2001
From: Pim de Wit <pim@pdw.io>
Date: Tue, 8 Oct 2019 18:49:45 +0100
Subject: [PATCH 1/2] feat(slidesInView): separation of concerns + added method
 to public api

---
 src/macro-carousel/macro-carousel.js | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/macro-carousel/macro-carousel.js b/src/macro-carousel/macro-carousel.js
index 3cc4d56..e886302 100644
--- a/src/macro-carousel/macro-carousel.js
+++ b/src/macro-carousel/macro-carousel.js
@@ -911,6 +911,19 @@ class MacroCarousel extends HTMLElement {
     return intGetter(this, 'slides-per-view', 1);
   }
 
+  /**
+   * Get the indexes of slides currently in view.
+   * @return {Array<number>}
+   */
+  get slidesInView() {
+    const slidesInViewIndexes = [];
+    for (let i = 0; i < this.slidesPerView; i++) {
+      slidesInViewIndexes.push((this.selected + i) % this._slides.length);
+    }
+
+    return slidesInViewIndexes;
+  }
+
   /**
    * If true, disables CSS transitions and drag deceleration.
    * @type {boolean}
@@ -1135,16 +1148,11 @@ value. Add CSS units to its value to avoid breaking the slides layout.`);
    * @private
    */
   _updateSlidesA11y() {
-    const slidesInView = [];
-    for (let i = 0; i < this.slidesPerView; i++) {
-      slidesInView.push((this.selected + i) % this._slides.length);
-    }
-
     // Set aria-hidden to false only for the slides whose indexes are included
     // in the slidesInView array.
     let isSlideInView;
     this._slides.map(slide => slide.element).forEach((slideEl, slideIndex) => {
-      isSlideInView = !isUndefined(slidesInView.find(i => i === slideIndex));
+      isSlideInView = !isUndefined(this.slidesInView.find(i => i === slideIndex));
       // Slides in view have `aria-hidden` set to `false`.
       slideEl.setAttribute(ATTRS.STANDARD.ARIA.HIDDEN,
           isSlideInView ? ATTR_VALUES.FALSE : ATTR_VALUES.TRUE);

From a6e1cf08dfcf6b7ea0e0253e0906f22372d87189 Mon Sep 17 00:00:00 2001
From: Pim de Wit <pim@pdw.io>
Date: Tue, 8 Oct 2019 21:07:05 +0100
Subject: [PATCH 2/2] test(MacroCarousel.slidesInView): added test

---
 test/selected-slides-per-view.js | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/test/selected-slides-per-view.js b/test/selected-slides-per-view.js
index 3387f03..41d5e2a 100644
--- a/test/selected-slides-per-view.js
+++ b/test/selected-slides-per-view.js
@@ -38,5 +38,13 @@
       await wcutils.flush();
       expect(this.slider.selected).to.equal(numberOfSlides - 1);
     });
+
+    it('returns indexes of slides in view', async function() {
+      this.slider.selected = 0;
+      this.slider.slidesPerView = 3;
+
+      await wcutils.flush();
+      expect(this.slider.slidesInView).to.deep.equal([0, 1, 2]);
+    });
   });
 })();