📝 fix: Properly Restore Draft Text When Switching Conversations (#12384)

Right now, if you have draft text in conversation A, but no draft text in
conversation B, then switching from A -> B inserts the draft from A into B
(oops).

This was caused by a bug in the `restoreText()` logic which did not
restore *blank* text as the saved draft.

Now, it'll always restore whatever is found as a draft (or set to blank if
there is no draft).

client/src/hooks/Input/useAutoSave.spec.ts

@@ -0,0 +1,110 @@
+jest.mock('recoil', () => ({
+  ...jest.requireActual('recoil'),
+  useRecoilValue: jest.fn(),
+}));
+
+jest.mock('~/store', () => ({
+  saveDrafts: { key: 'saveDrafts', default: true },
+}));
+
+jest.mock('~/Providers', () => ({
+  useChatFormContext: jest.fn(),
+}));
+
+jest.mock('~/data-provider', () => ({
+  useGetFiles: jest.fn(),
+}));
+
+jest.mock('~/utils', () => ({
+  ...jest.requireActual('~/utils'),
+  getDraft: jest.fn(),
+  setDraft: jest.fn(),
+  clearDraft: jest.fn(),
+  clearAllDrafts: jest.fn(),
+}));
+
+import React from 'react';
+import { renderHook, act } from '@testing-library/react';
+import { useRecoilValue } from 'recoil';
+import { useChatFormContext } from '~/Providers';
+import { useGetFiles } from '~/data-provider';
+import { getDraft, setDraft } from '~/utils';
+import store from '~/store';
+import { useAutoSave } from '~/hooks';
+
+const mockSetValue = jest.fn();
+const mockGetDraft = getDraft as jest.Mock;
+const mockSetDraft = setDraft as jest.Mock;
+
+const makeTextAreaRef = (value = '') =>
+  ({
+    current: { value, addEventListener: jest.fn(), removeEventListener: jest.fn() },
+  }) as unknown as React.RefObject<HTMLTextAreaElement>;
+
+beforeEach(() => {
+  (useRecoilValue as jest.Mock).mockImplementation((atom) => {
+    if (atom === store.saveDrafts) return true;
+    return undefined;
+  });
+  (useChatFormContext as jest.Mock).mockReturnValue({ setValue: mockSetValue });
+  (useGetFiles as jest.Mock).mockReturnValue({ data: [] });
+  mockGetDraft.mockReturnValue('');
+});
+
+describe('useAutoSave — conversation switching', () => {
+  it('clears the textarea when switching to a conversation with no draft', () => {
+    const { rerender } = renderHook(
+      ({ conversationId }: { conversationId: string }) =>
+        useAutoSave({
+          conversationId,
+          textAreaRef: makeTextAreaRef(),
+          files: new Map(),
+          setFiles: jest.fn(),
+        }),
+      { initialProps: { conversationId: 'convo-1' } },
+    );
+
+    act(() => {
+      rerender({ conversationId: 'convo-2' });
+    });
+
+    expect(mockSetValue).toHaveBeenLastCalledWith('text', '');
+  });
+
+  it('restores the saved draft when switching to a conversation with one', () => {
+    mockGetDraft.mockImplementation((id: string) => (id === 'convo-2' ? 'Hello, world!' : ''));
+
+    const { rerender } = renderHook(
+      ({ conversationId }: { conversationId: string }) =>
+        useAutoSave({
+          conversationId,
+          textAreaRef: makeTextAreaRef(),
+          files: new Map(),
+          setFiles: jest.fn(),
+        }),
+      { initialProps: { conversationId: 'convo-1' } },
+    );
+
+    act(() => {
+      rerender({ conversationId: 'convo-2' });
+    });
+
+    expect(mockSetValue).toHaveBeenLastCalledWith('text', 'Hello, world!');
+  });
+
+  it('saves the current textarea content before switching away', () => {
+    const textAreaRef = makeTextAreaRef('draft in progress');
+
+    const { rerender } = renderHook(
+      ({ conversationId }: { conversationId: string }) =>
+        useAutoSave({ conversationId, textAreaRef, files: new Map(), setFiles: jest.fn() }),
+      { initialProps: { conversationId: 'convo-1' } },
+    );
+
+    act(() => {
+      rerender({ conversationId: 'convo-2' });
+    });
+
+    expect(mockSetDraft).toHaveBeenCalledWith({ id: 'convo-1', value: 'draft in progress' });
+  });
+});

client/src/hooks/Input/useAutoSave.ts

@@ -73,11 +73,7 @@ export const useAutoSave = ({
 
   const restoreText = useCallback(
     (id: string) => {
-      const savedDraft = getDraft(id);
-      if (!savedDraft) {
-        return;
-      }
-      setValue('text', savedDraft);
+      setValue('text', getDraft(id) ?? '');
     },
     [setValue],
   );