From e6352bd0076c16068acb5532b5d7b9d943ae7434 Mon Sep 17 00:00:00 2001
From: Andrew Serong <14988353+andrewserong@users.noreply.github.com>
Date: Thu, 13 Apr 2023 14:32:45 +1000
Subject: [PATCH 1/2] DOM: Update getScrollContainer to be aware of horizontal
 scroll

---
 packages/dom/src/dom/get-scroll-container.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/packages/dom/src/dom/get-scroll-container.js b/packages/dom/src/dom/get-scroll-container.js
index 6c472e6195496..b2d8063e26aca 100644
--- a/packages/dom/src/dom/get-scroll-container.js
+++ b/packages/dom/src/dom/get-scroll-container.js
@@ -26,6 +26,16 @@ export default function getScrollContainer( node ) {
 		}
 	}
 
+	// Scrollable if scrollable width exceeds displayed...
+	if ( node.scrollWidth > node.clientWidth ) {
+		// ...except when overflow is defined to be hidden or visible
+		const { overflowX } = getComputedStyle( node );
+
+		if ( /(auto|scroll)/.test( overflowX ) ) {
+			return node;
+		}
+	}
+
 	if ( node.ownerDocument === node.parentNode ) {
 		return node;
 	}

From dda80bdeea7bf80f979bae0d4dc79a51be24d171 Mon Sep 17 00:00:00 2001
From: Andrew Serong <14988353+andrewserong@users.noreply.github.com>
Date: Fri, 14 Apr 2023 10:30:36 +1000
Subject: [PATCH 2/2] Update to add a direction param

---
 packages/dom/README.md                       |  1 +
 packages/dom/src/dom/get-scroll-container.js | 40 ++++++++++++--------
 2 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/packages/dom/README.md b/packages/dom/README.md
index 4a2fc100174e1..f87ccbb3ac731 100644
--- a/packages/dom/README.md
+++ b/packages/dom/README.md
@@ -131,6 +131,7 @@ Given a DOM node, finds the closest scrollable container node or the node itself
 _Parameters_
 
 -   _node_ `Element | null`: Node from which to start.
+-   _direction_ `?string`: Direction of scrollable container to search for ('vertical', 'horizontal', 'all'). Defaults to 'vertical'.
 
 _Returns_
 
diff --git a/packages/dom/src/dom/get-scroll-container.js b/packages/dom/src/dom/get-scroll-container.js
index b2d8063e26aca..da46f23c660ba 100644
--- a/packages/dom/src/dom/get-scroll-container.js
+++ b/packages/dom/src/dom/get-scroll-container.js
@@ -7,32 +7,37 @@ import getComputedStyle from './get-computed-style';
  * Given a DOM node, finds the closest scrollable container node or the node
  * itself, if scrollable.
  *
- * @param {Element | null} node Node from which to start.
- *
+ * @param {Element | null} node      Node from which to start.
+ * @param {?string}        direction Direction of scrollable container to search for ('vertical', 'horizontal', 'all').
+ *                                   Defaults to 'vertical'.
  * @return {Element | undefined} Scrollable container node, if found.
  */
-export default function getScrollContainer( node ) {
+export default function getScrollContainer( node, direction = 'vertical' ) {
 	if ( ! node ) {
 		return undefined;
 	}
 
-	// Scrollable if scrollable height exceeds displayed...
-	if ( node.scrollHeight > node.clientHeight ) {
-		// ...except when overflow is defined to be hidden or visible
-		const { overflowY } = getComputedStyle( node );
+	if ( direction === 'vertical' || direction === 'all' ) {
+		// Scrollable if scrollable height exceeds displayed...
+		if ( node.scrollHeight > node.clientHeight ) {
+			// ...except when overflow is defined to be hidden or visible
+			const { overflowY } = getComputedStyle( node );
 
-		if ( /(auto|scroll)/.test( overflowY ) ) {
-			return node;
+			if ( /(auto|scroll)/.test( overflowY ) ) {
+				return node;
+			}
 		}
 	}
 
-	// Scrollable if scrollable width exceeds displayed...
-	if ( node.scrollWidth > node.clientWidth ) {
-		// ...except when overflow is defined to be hidden or visible
-		const { overflowX } = getComputedStyle( node );
+	if ( direction === 'horizontal' || direction === 'all' ) {
+		// Scrollable if scrollable width exceeds displayed...
+		if ( node.scrollWidth > node.clientWidth ) {
+			// ...except when overflow is defined to be hidden or visible
+			const { overflowX } = getComputedStyle( node );
 
-		if ( /(auto|scroll)/.test( overflowX ) ) {
-			return node;
+			if ( /(auto|scroll)/.test( overflowX ) ) {
+				return node;
+			}
 		}
 	}
 
@@ -41,5 +46,8 @@ export default function getScrollContainer( node ) {
 	}
 
 	// Continue traversing.
-	return getScrollContainer( /** @type {Element} */ ( node.parentNode ) );
+	return getScrollContainer(
+		/** @type {Element} */ ( node.parentNode ),
+		direction
+	);
 }