Tweak send no-response handling

app/services/message_send.py

@@ -20,6 +20,11 @@ from app.services.messages import (
 
 logger = logging.getLogger(__name__)
 
+NO_RADIO_RESPONSE_AFTER_SEND_DETAIL = (
+    "Send command was issued to the radio, but no response was heard back. "
+    "The message may or may not have sent successfully."
+)
+
 BroadcastFn = Callable[..., Any]
 TrackAckFn = Callable[[str, int, int], bool]
 NowFn = Callable[[], float]
@@ -279,7 +284,14 @@ async def send_direct_message_to_contact(
                 timestamp=sender_timestamp,
             )
 
-        if result is None or result.type == EventType.ERROR:
+        if result is None:
+            logger.warning(
+                "No response from radio after direct send to %s; send outcome is unknown",
+                contact.public_key[:12],
+            )
+            raise HTTPException(status_code=504, detail=NO_RADIO_RESPONSE_AFTER_SEND_DETAIL)
+
+        if result.type == EventType.ERROR:
             raise HTTPException(status_code=500, detail=f"Failed to send message: {result.payload}")
 
         message = await create_outgoing_direct_message(

frontend/src/components/MessageInput.tsx

@@ -24,6 +24,7 @@ const CHANNEL_WARNING_THRESHOLD = 120; // Conservative for multi-hop
 const CHANNEL_DANGER_BUFFER = 8; // Red zone starts this many bytes before hard limit
 
 const textEncoder = new TextEncoder();
+const RADIO_NO_RESPONSE_SNIPPET = 'no response was heard back';
 /** Get UTF-8 byte length of a string (LoRa packets are byte-constrained, not character-constrained). */
 function byteLen(s: string): number {
   return textEncoder.encode(s).length;
@@ -118,8 +119,11 @@ export const MessageInput = forwardRef<MessageInputHandle, MessageInputProps>(fu
         setText('');
       } catch (err) {
         console.error('Failed to send message:', err);
-        toast.error('Failed to send message', {
-          description: err instanceof Error ? err.message : 'Check radio connection',
+        const description = err instanceof Error ? err.message : 'Check radio connection';
+        const isRadioNoResponse =
+          err instanceof Error && err.message.toLowerCase().includes(RADIO_NO_RESPONSE_SNIPPET);
+        toast.error(isRadioNoResponse ? 'Radio did not confirm send' : 'Failed to send message', {
+          description,
         });
         return;
       } finally {

frontend/src/test/messageInput.test.tsx

@@ -9,12 +9,18 @@ import { render, screen, fireEvent } from '@testing-library/react';
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 
 import { MessageInput } from '../components/MessageInput';
+import { toast } from '../components/ui/sonner';
 
 // Mock sonner (toast)
 vi.mock('../components/ui/sonner', () => ({
   toast: { success: vi.fn(), error: vi.fn() },
 }));
 
+const mockToast = toast as unknown as {
+  success: ReturnType<typeof vi.fn>;
+  error: ReturnType<typeof vi.fn>;
+};
+
 const textEncoder = new TextEncoder();
 
 function byteLen(s: string): number {
@@ -182,4 +188,24 @@ describe('MessageInput', () => {
       expect(getSendButton()).toBeEnabled();
     });
   });
+
+  describe('send failure toasts', () => {
+    it('shows the radio no-response toast when the send outcome is unknown', async () => {
+      onSend.mockRejectedValueOnce(
+        new Error(
+          'Send command was issued to the radio, but no response was heard back. The message may or may not have sent successfully.'
+        )
+      );
+      renderInput({ conversationType: 'contact' });
+
+      fireEvent.change(getInput(), { target: { value: 'Hello' } });
+      fireEvent.click(getSendButton());
+
+      expect(await screen.findByDisplayValue('Hello')).toBeTruthy();
+      expect(mockToast.error).toHaveBeenCalledWith('Radio did not confirm send', {
+        description:
+          'Send command was issued to the radio, but no response was heard back. The message may or may not have sent successfully.',
+      });
+    });
+  });
 });

tests/test_send_messages.py

@@ -25,6 +25,7 @@ from app.routers.messages import (
     send_direct_message,
 )
 from app.services import dm_ack_tracker
+from app.services.message_send import NO_RADIO_RESPONSE_AFTER_SEND_DETAIL
 
 
 @pytest.fixture(autouse=True)
@@ -1024,6 +1025,32 @@ class TestRadioExceptionMidSend:
         )
         assert len(messages) == 0
 
+    @pytest.mark.asyncio
+    async def test_dm_send_no_radio_response_returns_504_without_storing_message(self, test_db):
+        """When mc.commands.send_msg() returns None, report unknown outcome and store nothing."""
+        mc = _make_mc()
+        pub_key = "ac" * 32
+        await _insert_contact(pub_key, "Alice")
+
+        mc.commands.send_msg = AsyncMock(return_value=None)
+
+        with (
+            patch("app.routers.messages.require_connected", return_value=mc),
+            patch.object(radio_manager, "_meshcore", mc),
+            pytest.raises(HTTPException) as exc_info,
+        ):
+            await send_direct_message(
+                SendDirectMessageRequest(destination=pub_key, text="Did this send?")
+            )
+
+        assert exc_info.value.status_code == 504
+        assert exc_info.value.detail == NO_RADIO_RESPONSE_AFTER_SEND_DETAIL
+
+        messages = await MessageRepository.get_all(
+            msg_type="PRIV", conversation_key=pub_key, limit=10
+        )
+        assert len(messages) == 0
+
     @pytest.mark.asyncio
     async def test_channel_send_radio_exception_no_orphan_message(self, test_db):
         """When mc.commands.send_chan_msg() raises, no message should be stored in DB."""