raise error if completed transform has no files

servicex/query_core.py

@@ -452,6 +452,23 @@ async def transform_status_listener(
                     else ""
                 )
                 if self.current_status.status == Status.complete:
+                    if self.current_status.files == 0:
+                        err_str = (
+                            f"Transform {titlestr}completed with 0 files. "
+                            "This might indicate an invalid dataset identifier (DID). "
+                        )
+                        if self.current_status.log_url is not None:
+                            kibana_link = create_kibana_link_parameters(
+                                self.current_status.log_url,
+                                self.current_status.request_id,
+                                LogLevel.error,
+                                TimeFrame.month,
+                            )
+                            logger.error(
+                                f"{err_str}\nMore logfiles of '{self.title}' [bold red on white][link={kibana_link}]HERE[/link][/bold red on white]"  # NOQA: E501
+                            )
+                        raise ServiceXException(err_str)
+
                     if self.files_failed:
                         bar = "failure"
                     else:

tests/test_dataset.py

@@ -250,6 +250,63 @@ async def test_transform_status_listener_cancelled(python_dataset):
             assert python_dataset.files_failed == 1
 
 
+@pytest.mark.asyncio
+async def test_transform_status_listener_zero_files_no_log_url(python_dataset):
+    progress = Mock(spec=Progress)
+    progress_task = Mock()
+    download_task = Mock()
+    status = Mock(
+        files=0,
+        files_completed=0,
+        files_failed=0,
+        status=Status.complete,
+        log_url=None,
+        title="Test Transform",
+    )
+    python_dataset.current_status = status
+    python_dataset.retrieve_current_transform_status = AsyncMock(return_value=status)
+
+    with pytest.raises(ServiceXException, match=r"Transform.*completed with 0 files"):
+        await python_dataset.transform_status_listener(
+            progress, progress_task, "mock_title", download_task, "mock_title"
+        )
+
+    python_dataset.retrieve_current_transform_status.assert_awaited_once()
+
+
+@pytest.mark.asyncio
+async def test_transform_status_listener_zero_files_with_log_url(python_dataset):
+    progress = Mock(spec=Progress)
+    progress_task = Mock()
+    download_task = Mock()
+    status = Mock(
+        files=0,
+        files_completed=0,
+        files_failed=0,
+        status=Status.complete,
+        log_url="http://example.com/logs",
+        request_id="test-request-123",
+        title="Test Transform",
+    )
+    python_dataset.current_status = status
+    python_dataset.retrieve_current_transform_status = AsyncMock(return_value=status)
+
+    with pytest.raises(ServiceXException, match=r"Transform.*completed with 0 files"):
+        with patch(
+            "servicex.app.transforms.create_kibana_link_parameters"
+        ) as mock_link:
+            with patch("servicex.query_core.logger") as mock_logger:
+                mock_link.return_value = "http://kibana.example.com/link"
+                await python_dataset.transform_status_listener(
+                    progress, progress_task, "mock_title", download_task, "mock_title"
+                )
+
+                mock_link.assert_called_once()
+                mock_logger.error.assert_called_once()
+
+    python_dataset.retrieve_current_transform_status.assert_awaited_once()
+
+
 @pytest.mark.asyncio
 async def test_retrieve_current_transform_status_status_none(
     python_dataset, completed_status