feat(TreeView): add support for Backspace to collapse a folder

.changeset/fast-shoes-enjoy.md

@@ -0,0 +1,5 @@
+---
+'@primer/react': patch
+---
+
+Add support for Backspace to collapse group in TreeView

package.json

@@ -82,7 +82,7 @@
     "@github/combobox-nav": "^2.1.5",
     "@github/markdown-toolbar-element": "^2.1.0",
     "@github/paste-markdown": "^1.4.0",
-    "@primer/behaviors": "1.3.0",
+    "@primer/behaviors": "1.3.1-rc.8de3bf8",
     "@primer/octicons-react": "^17.7.0",
     "@primer/primitives": "7.10.0",
     "@react-aria/ssr": "^3.1.0",

src/TreeView/TreeView.test.tsx

@@ -580,6 +580,64 @@ describe('Keyboard interactions', () => {
     })
   })
 
+  describe('Backspace', () => {
+    it('should move focus to the parent item', () => {
+      const {getByRole} = renderWithTheme(
+        <TreeView aria-label="Test tree">
+          <TreeView.Item defaultExpanded>
+            Parent
+            <TreeView.SubTree>
+              <TreeView.Item>Child</TreeView.Item>
+            </TreeView.SubTree>
+          </TreeView.Item>
+        </TreeView>
+      )
+
+      const parentItem = getByRole('treeitem', {name: 'Parent'})
+      const child = getByRole('treeitem', {name: 'Child'})
+      child.focus()
+
+      // Press Backspace
+      fireEvent.keyDown(document.activeElement || document.body, {key: 'Backspace'})
+
+      expect(parentItem).toHaveFocus()
+    })
+
+    it('should not collapse an expanded item', () => {
+      const {getByRole, queryByRole} = renderWithTheme(
+        <TreeView aria-label="Test tree">
+          <TreeView.Item defaultExpanded>
+            Parent
+            <TreeView.SubTree>
+              <TreeView.Item>Child</TreeView.Item>
+            </TreeView.SubTree>
+          </TreeView.Item>
+        </TreeView>
+      )
+
+      const parentItem = getByRole('treeitem', {name: 'Parent'})
+      const subtree = queryByRole('group')
+
+      // aria-expanded should be true
+      expect(parentItem).toHaveAttribute('aria-expanded', 'true')
+
+      // Subtree should be visible
+      expect(subtree).toBeVisible()
+
+      // Focus first item
+      parentItem.focus()
+
+      // Press Backspace
+      fireEvent.keyDown(document.activeElement || document.body, {key: 'Backspace'})
+
+      // aria-expanded should stay set as true
+      expect(parentItem).toHaveAttribute('aria-expanded', 'true')
+
+      // Parent item should still be focused
+      expect(parentItem).toHaveFocus()
+    })
+  })
+
   describe('Home', () => {
     it('moves focus to first visible item', () => {
       const {getByRole} = renderWithTheme(
@@ -1110,6 +1168,12 @@ describe('Asyncronous loading', () => {
 
     // Parent item should still be expanded
     expect(parentItem).toHaveAttribute('aria-expanded', 'true')
+
+    // Press Backspace
+    fireEvent.keyDown(document.activeElement || document.body, {key: 'Backspace'})
+
+    // Parent item should still be expanded
+    expect(parentItem).toHaveAttribute('aria-expanded', 'true')
   })
 
   it('should remove `aria-expanded` if no content is loaded in', async () => {

src/TreeView/TreeView.tsx

@@ -716,7 +716,7 @@ const ErrorDialog: React.FC<TreeViewErrorDialogProps> = ({title = 'Error', child
     // eslint-disable-next-line jsx-a11y/no-static-element-interactions
     <div
       onKeyDown={event => {
-        if (['ArrowLeft', 'ArrowRight', 'ArrowUp', 'ArrowDown', 'Enter'].includes(event.key)) {
+        if (['Backspace', 'ArrowLeft', 'ArrowRight', 'ArrowUp', 'ArrowDown', 'Enter'].includes(event.key)) {
           // Prevent keyboard events from bubbling up to the TreeView
           // and interfering with keyboard navigation
           event.stopPropagation()

src/TreeView/useRovingTabIndex.ts

@@ -5,7 +5,7 @@ export function useRovingTabIndex({containerRef}: {containerRef: React.RefObject
   // TODO: Initialize focus to the aria-current item if it exists
   useFocusZone({
     containerRef,
-    bindKeys: FocusKeys.ArrowVertical | FocusKeys.ArrowHorizontal | FocusKeys.HomeAndEnd,
+    bindKeys: FocusKeys.ArrowVertical | FocusKeys.ArrowHorizontal | FocusKeys.HomeAndEnd | FocusKeys.Backspace,
     preventScroll: true,
     getNextFocusable: (direction, from, event) => {
       if (!(from instanceof HTMLElement)) return
@@ -30,20 +30,26 @@ export function getNextFocusableElement(activeElement: HTMLElement, event: Keybo
       // Close node; don't change focus
       return
 
+    // Focus parent element
+    case 'open Backspace':
+      return getParentElement(activeElement)
+
     case 'closed ArrowRight':
       // Open node; don't change focus
       return
 
+    // Focus parent element
     case 'closed ArrowLeft':
-      // Focus parent element
+    case 'closed Backspace':
       return getParentElement(activeElement)
 
     case 'end ArrowRight':
       // Do nothing
       return
 
+    // Focus parent element
     case 'end ArrowLeft':
-      // Focus parent element
+    case 'end Backspace':
       return getParentElement(activeElement)
   }