Add unit test to check tuning is persistent after picamera calibration and modifying LST

hardware-specific-tests/picamera2/test_calibration.py

@@ -1,6 +1,7 @@
 """Test data collection from the Raspberry Picamera."""
 
 from copy import deepcopy
+import tempfile
 
 import pytest
 
@@ -10,6 +11,8 @@ from openflexure_microscope_server.things.camera.picamera import (
     MissingCalibrationError,
 )
 
+from .cam_test_utils import camera_test_client
+
 
 def test_get_tuning_algo(picamera_thing):
     """Test that get_tuning algorithm retrieves tuning algorithms."""
@@ -73,3 +76,41 @@ def test_calibration(picamera_thing, picamera_client):
     # Green equalisation offset should be set to maximum.
     assert picamera_thing.get_tuning_algo("rpi.geq")["offset"] == 65535
     assert picamera_thing.background_detector_status.ready
+
+
+def test_tuning_is_persistent():
+    """Check that tuning file adjustments are persistent."""
+    # First check full auto-calibrate is persistent if same save dir is used.
+    with tempfile.TemporaryDirectory() as tmpdir:
+        with camera_test_client(settings_folder=tmpdir) as client:
+            initial_tuning = deepcopy(client.tuning)
+            client.full_auto_calibrate()
+            calibrated_tuning = deepcopy(client.tuning)
+            # Full auto calibrate should have saved the tuning.
+            assert initial_tuning != calibrated_tuning
+
+        # Reload the camera and server from scratch
+        with camera_test_client(settings_folder=tmpdir) as client:
+            initial_tuning = deepcopy(client.tuning)
+            # On reload the initial tuning is as it was when calibrated last run
+            assert initial_tuning == calibrated_tuning
+            # Set the lens shading to be flat
+            client.flat_lens_shading()
+            flat_tuning = deepcopy(client.tuning)
+            assert flat_tuning != calibrated_tuning
+
+        # Reload to check the flat lst persists
+        with camera_test_client(settings_folder=tmpdir) as client:
+            initial_tuning = deepcopy(client.tuning)
+            # On reload the initial tuning the flat tuning
+            assert initial_tuning == flat_tuning
+            # Reset the lens shading to what is in the default tuning file
+            client.reset_lens_shading()
+            flat_tuning = deepcopy(client.tuning)
+            assert flat_tuning != calibrated_tuning
+
+        # Reload the one more time to check the reset lst persists
+        with camera_test_client(settings_folder=tmpdir) as client:
+            initial_tuning = deepcopy(client.tuning)
+            # On reload the initial tuning the flat tuning
+            assert initial_tuning == flat_tuning