fix(core): show an empty message preview when there is nothing to describe

package/src/hooks/messagePreview/__tests__/useMessagePreviewText.test.tsx

@@ -0,0 +1,59 @@
+import React, { PropsWithChildren } from 'react';
+
+import { renderHook, waitFor } from '@testing-library/react-native';
+
+import type { Attachment } from 'stream-chat';
+
+import { Chat } from '../../../components/Chat/Chat';
+import { initiateClientWithChannels } from '../../../mock-builders/api/initiateClientWithChannels';
+import {
+  generateAudioAttachment,
+  generateFileAttachment,
+  generateImageAttachment,
+} from '../../../mock-builders/attachments';
+import { generateMessage } from '../../../mock-builders/generator/message';
+import { useMessagePreviewText } from '../useMessagePreviewText';
+
+describe('useMessagePreviewText', () => {
+  const render = async (message: ReturnType<typeof generateMessage>) => {
+    const { client } = await initiateClientWithChannels();
+    const wrapper = ({ children }: PropsWithChildren) => <Chat client={client}>{children}</Chat>;
+    const { result } = renderHook(() => useMessagePreviewText({ message }), { wrapper });
+    return result;
+  };
+
+  const withAttachments = (attachments?: Attachment[]) =>
+    generateMessage({ attachments, text: '' });
+
+  // Drafts can have no text and no attachments; they rendered "{{count}} Files" / "0 Audios".
+  it.each([
+    ['absent', undefined],
+    ['empty', []],
+  ])('returns an empty preview when attachments are %s', async (_, attachments) => {
+    const result = await render(withAttachments(attachments));
+    expect(result.current).toBe('');
+  });
+
+  it('counts mixed attachments as files', async () => {
+    const result = await render(
+      withAttachments([generateImageAttachment(), generateFileAttachment()]),
+    );
+    // Counted copy comes from the translations, which load asynchronously.
+    await waitFor(() => expect(result.current).toBe('2 Files'));
+  });
+
+  it('counts audio-only attachments as audios', async () => {
+    const result = await render(
+      withAttachments([generateAudioAttachment(), generateAudioAttachment()]),
+    );
+    // Counted copy comes from the translations, which load asynchronously.
+    await waitFor(() => expect(result.current).toBe('2 Audios'));
+  });
+
+  it('prefers the message text over its attachments', async () => {
+    const result = await render(
+      generateMessage({ attachments: [generateFileAttachment()], text: 'hello' }),
+    );
+    expect(result.current).toBe('hello');
+  });
+});

package/src/hooks/messagePreview/useMessagePreviewText.tsx

@@ -64,6 +64,10 @@ export const useMessagePreviewText = ({
     return message.text;
   }
 
+  if (!attachmentsLength) {
+    return '';
+  }
+
   if (onlyImages) {
     if (images?.length === 1) {
       return t('Photo');