From 8662c0b1bb1cb0c08abd745e38a6ac59246962c7 Mon Sep 17 00:00:00 2001
From: Aleksander Nowodzinski <a.nowodzinski@cksource.com>
Date: Mon, 12 Aug 2019 15:38:52 +0200
Subject: [PATCH] Implemented the aria-expanded attribute support on the
 SplitButtonView#arrowView element.

---
 src/dropdown/button/splitbuttonview.js   | 4 +++-
 tests/dropdown/button/splitbuttonview.js | 8 ++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/dropdown/button/splitbuttonview.js b/src/dropdown/button/splitbuttonview.js
index f8fdf2ba..ca4fd171 100644
--- a/src/dropdown/button/splitbuttonview.js
+++ b/src/dropdown/button/splitbuttonview.js
@@ -204,13 +204,15 @@ export default class SplitButtonView extends View {
 	 */
 	_createArrowView() {
 		const arrowView = new ButtonView();
+		const bind = arrowView.bindTemplate;
 
 		arrowView.icon = dropdownArrowIcon;
 
 		arrowView.extendTemplate( {
 			attributes: {
 				class: 'ck-splitbutton__arrow',
-				'aria-haspopup': true
+				'aria-haspopup': true,
+				'aria-expanded': bind.to( 'isOn', value => String( value ) )
 			}
 		} );
 
diff --git a/tests/dropdown/button/splitbuttonview.js b/tests/dropdown/button/splitbuttonview.js
index 2fcaba5a..29c51336 100644
--- a/tests/dropdown/button/splitbuttonview.js
+++ b/tests/dropdown/button/splitbuttonview.js
@@ -70,6 +70,14 @@ describe( 'SplitButtonView', () => {
 			expect( view.element.classList.contains( 'ck-splitbutton_open' ) ).to.be.false;
 		} );
 
+		it( 'binds arrowView aria-expanded attribute to #isOn', () => {
+			view.arrowView.isOn = true;
+			expect( view.arrowView.element.getAttribute( 'aria-expanded' ) ).to.equal( 'true' );
+
+			view.arrowView.isOn = false;
+			expect( view.arrowView.element.getAttribute( 'aria-expanded' ) ).to.equal( 'false' );
+		} );
+
 		describe( 'activates keyboard navigation for the toolbar', () => {
 			it( 'so "arrowright" on view#arrowView does nothing', () => {
 				const keyEvtData = {