fix: tablist auto selection

packages/@react-stately/tabs/src/useTabListState.ts

@@ -43,7 +43,7 @@ export function useTabListState<T extends object>(props: TabListStateOptions<T>)
   useEffect(() => {
     // Ensure a tab is always selected (in case no selected key was specified or if selected item was deleted from collection)
     let selectedKey = currentSelectedKey;
-    if (selectionManager.isEmpty || selectedKey == null || !collection.getItem(selectedKey)) {
+    if (props.selectedKey == null && (selectionManager.isEmpty || selectedKey == null || !collection.getItem(selectedKey))) {
       selectedKey = findDefaultSelectedKey(collection, state.disabledKeys);
       if (selectedKey != null) {
         // directly set selection because replace/toggle selection won't consider disabled keys

packages/react-aria-components/test/Tabs.test.js

@@ -10,9 +10,9 @@
  * governing permissions and limitations under the License.
  */
 
+import {Button, Collection, Tab, TabList, TabPanel, Tabs} from '../';
 import {fireEvent, pointerMap, render, waitFor, within} from '@react-spectrum/test-utils-internal';
-import React from 'react';
-import {Tab, TabList, TabPanel, Tabs} from '../';
+import React, {useState} from 'react';
 import {TabsExample} from '../stories/Tabs.stories';
 import {User} from '@react-aria/test-utils';
 import userEvent from '@testing-library/user-event';
@@ -497,4 +497,102 @@ describe('Tabs', () => {
     expect(innerTabs[0]).toHaveTextContent('One');
     expect(innerTabs[1]).toHaveTextContent('Two');
   });
+
+  it('can add tabs and keep the current selected key', async () => {
+    let onSelectionChange = jest.fn();
+    function Example(props) {
+      let [tabs, setTabs] = useState([
+        {id: 1, title: 'Tab 1', content: 'Tab body 1'},
+        {id: 2, title: 'Tab 2', content: 'Tab body 2'},
+        {id: 3, title: 'Tab 3', content: 'Tab body 3'}
+      ]);
+
+      const [selectedTabId, setSelectedTabId] = useState(tabs[0].id);
+
+      let addTab = () => {
+        const tabId = tabs.length + 1;
+
+        setTabs((prevTabs) => [
+          ...prevTabs,
+          {
+            id: tabId,
+            title: `Tab ${tabId}`,
+            content: `Tab body ${tabId}`
+          }
+        ]);
+
+        // Use functional update to ensure you're working with the most recent state
+        setSelectedTabId(tabId);
+      };
+
+      let removeTab = () => {
+        if (tabs.length > 1) {
+          setTabs((prevTabs) => {
+            const updatedTabs = prevTabs.slice(0, -1);
+            // Update selectedTabId to the last remaining tab's ID if the current selected tab is removed
+            const newSelectedTabId = updatedTabs[updatedTabs.length - 1].id;
+            setSelectedTabId(newSelectedTabId);
+            return updatedTabs;
+          });
+        }
+      };
+
+      const onSelectionChange = (value) => {
+        setSelectedTabId(value);
+        props.onSelectionChange(value);
+      };
+
+      return (
+        <Tabs selectedKey={selectedTabId} onSelectionChange={onSelectionChange}>
+          <div style={{display: 'flex'}}>
+            <TabList aria-label="Dynamic tabs" items={tabs} style={{flex: 1}}>
+              {(item) => (
+                <Tab>
+                  {({isSelected}) => (
+                    <p
+                      style={{
+                        color: isSelected ? 'red' : 'black'
+                      }}>
+                      {item.title}
+                    </p>
+                  )}
+                </Tab>
+              )}
+            </TabList>
+            <div className="button-group">
+              <Button onPress={addTab}>Add tab</Button>
+              <Button onPress={removeTab}>Remove tab</Button>
+            </div>
+          </div>
+          <Collection items={tabs}>
+            {(item) => (
+              <TabPanel
+                style={{
+                  borderTop: '2px solid black'
+                }}>
+                {item.content}
+              </TabPanel>
+            )}
+          </Collection>
+        </Tabs>
+      );
+    }
+    let {getAllByRole} = render(<Example onSelectionChange={onSelectionChange} />);
+    let tabs = getAllByRole('tab');
+    await user.tab();
+    await user.keyboard('{ArrowRight}');
+    expect(tabs[1]).toHaveAttribute('aria-selected', 'true');
+    await user.tab();
+    onSelectionChange.mockClear();
+    await user.keyboard('{Enter}');
+    expect(onSelectionChange).not.toHaveBeenCalled();
+    tabs = getAllByRole('tab');
+    expect(tabs[3]).toHaveAttribute('aria-selected', 'true');
+
+    await user.tab();
+    await user.keyboard('{Enter}');
+    expect(onSelectionChange).not.toHaveBeenCalled();
+    tabs = getAllByRole('tab');
+    expect(tabs[2]).toHaveAttribute('aria-selected', 'true');
+  });
 });