From 26a2e1a5825191eb377a072c71f4fd3a4ac6613c Mon Sep 17 00:00:00 2001
From: Julian Stirling <julian@julianstirling.co.uk>
Date: Thu, 2 Jul 2026 15:36:38 +0100
Subject: [PATCH] Type narrowing for mypy

---
 .../things/smart_scan.py                           | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/openflexure_microscope_server/things/smart_scan.py b/src/openflexure_microscope_server/things/smart_scan.py
index 7103e69f..a6da0b51 100644
--- a/src/openflexure_microscope_server/things/smart_scan.py
+++ b/src/openflexure_microscope_server/things/smart_scan.py
@@ -363,9 +363,10 @@ class SmartScanThing(OFMThing):
             self._preview_stitcher = None
 
             # Set the final details so they persist until the next scan
-            self._latest_scan_live_details.image_count = final_image_count
-            self._latest_scan_live_details.stitch_timestamp = last_timestamp
-            self._latest_scan_live_details.scan_phase = "Complete"
+            if self._latest_scan_live_details is not None:
+                self._latest_scan_live_details.image_count = final_image_count
+                self._latest_scan_live_details.stitch_timestamp = last_timestamp
+                self._latest_scan_live_details.scan_phase = "Complete"
 
             # Remove any scan folders containing zero images.
             self.purge_empty_scans()
@@ -480,8 +481,8 @@ class SmartScanThing(OFMThing):
                     overlap=stitching_settings.overlap,
                     correlation_resize=stitching_settings.correlation_resize,
                 )
-
-            self._latest_scan_live_details.scan_phase = "Scanning"
+            if self._latest_scan_live_details is not None:
+                self._latest_scan_live_details.scan_phase = "Scanning"
             # This is the main loop of the scan!
             self._main_scan_loop(workflow)
             self._save_final_scan_data(scan_result="success")
@@ -586,7 +587,8 @@ class SmartScanThing(OFMThing):
     @_scan_running
     def _perform_final_stitch(self) -> None:
         """Update the scan zip and perform final stitch of the data."""
-        self._latest_scan_live_details.scan_phase = "Stitching"
+        if self._latest_scan_live_details is not None:
+            self._latest_scan_live_details.scan_phase = "Stitching"
         if self.scan_data.image_count <= 1:
             self.logger.info("Not performing a stitch as not enough images captured")
             return