Forward whole message to FE on resend so the browser updates

frontend/src/api.ts

@@ -34,6 +34,12 @@ import type {
   UnreadCounts,
 } from './types';
 
+export interface ResendChannelMessageResponse {
+  status: string;
+  message_id: number;
+  message?: Message;
+}
+
 const API_BASE = '/api';
 
 async function fetchJson<T>(url: string, options?: RequestInit): Promise<T> {
@@ -238,7 +244,7 @@ export const api = {
       body: JSON.stringify({ channel_key: channelKey, text }),
     }),
   resendChannelMessage: (messageId: number, newTimestamp?: boolean) =>
-    fetchJson<{ status: string; message_id: number }>(
+    fetchJson<ResendChannelMessageResponse>(
       `/messages/channel/${messageId}/resend${newTimestamp ? '?new_timestamp=true' : ''}`,
       { method: 'POST' }
     ),

frontend/src/hooks/useConversationActions.ts

@@ -69,7 +69,16 @@ export function useConversationActions({
   const handleResendChannelMessage = useCallback(
     async (messageId: number, newTimestamp?: boolean) => {
       try {
-        await api.resendChannelMessage(messageId, newTimestamp);
+        const resent = await api.resendChannelMessage(messageId, newTimestamp);
+        const resentMessage = resent.message;
+        if (
+          newTimestamp &&
+          resentMessage &&
+          activeConversationRef.current?.type === 'channel' &&
+          activeConversationRef.current.id === resentMessage.conversation_key
+        ) {
+          addMessageIfNew(resentMessage);
+        }
         toast.success(newTimestamp ? 'Message resent with new timestamp' : 'Message resent');
       } catch (err) {
         toast.error('Failed to resend', {
@@ -77,7 +86,7 @@ export function useConversationActions({
         });
       }
     },
-    []
+    [activeConversationRef, addMessageIfNew]
   );
 
   const handleSetChannelFloodScopeOverride = useCallback(

frontend/src/test/useConversationActions.test.ts

@@ -125,6 +125,74 @@ describe('useConversationActions', () => {
     expect(args.messageInputRef.current?.appendText).toHaveBeenCalledWith('@[Alice] ');
   });
 
+  it('appends a new-timestamp resend immediately for the active channel', async () => {
+    const resentMessage: Message = {
+      ...sentMessage,
+      id: 99,
+      sender_timestamp: 1700000100,
+      received_at: 1700000100,
+    };
+    mocks.api.resendChannelMessage.mockResolvedValue({
+      status: 'ok',
+      message_id: resentMessage.id,
+      message: resentMessage,
+    });
+    const args = createArgs();
+
+    const { result } = renderHook(() => useConversationActions(args));
+
+    await act(async () => {
+      await result.current.handleResendChannelMessage(sentMessage.id, true);
+    });
+
+    expect(mocks.api.resendChannelMessage).toHaveBeenCalledWith(sentMessage.id, true);
+    expect(args.addMessageIfNew).toHaveBeenCalledWith(resentMessage);
+  });
+
+  it('does not append a byte-perfect resend locally', async () => {
+    mocks.api.resendChannelMessage.mockResolvedValue({
+      status: 'ok',
+      message_id: sentMessage.id,
+    });
+    const args = createArgs();
+
+    const { result } = renderHook(() => useConversationActions(args));
+
+    await act(async () => {
+      await result.current.handleResendChannelMessage(sentMessage.id, false);
+    });
+
+    expect(args.addMessageIfNew).not.toHaveBeenCalled();
+  });
+
+  it('does not append a resend if the user has switched conversations', async () => {
+    const resentMessage: Message = {
+      ...sentMessage,
+      id: 100,
+      sender_timestamp: 1700000200,
+      received_at: 1700000200,
+    };
+    mocks.api.resendChannelMessage.mockResolvedValue({
+      status: 'ok',
+      message_id: resentMessage.id,
+      message: resentMessage,
+    });
+    const args = createArgs();
+    const { result } = renderHook(() => useConversationActions(args));
+
+    await act(async () => {
+      const resendPromise = result.current.handleResendChannelMessage(sentMessage.id, true);
+      args.activeConversationRef.current = {
+        type: 'channel',
+        id: 'AA'.repeat(16),
+        name: 'Other',
+      };
+      await resendPromise;
+    });
+
+    expect(args.addMessageIfNew).not.toHaveBeenCalled();
+  });
+
   it('merges returned contact data after path discovery', async () => {
     const contactKey = 'aa'.repeat(32);
     const discoveredContact: Contact = {