[codex] Preserve legacy device model names on read

src/pynwb/io/device.py

@@ -5,6 +5,13 @@
 from .core import NWBContainerMapper
 
 
+def _construct_legacy_device_model(**kwargs):
+    model = DeviceModel.__new__(DeviceModel, in_construct_mode=True)
+    model.__init__(**kwargs)
+    model._in_construct_mode = False
+    return model
+
+
 @register_map(Device)
 class DeviceMapper(NWBContainerMapper):
     """
@@ -38,7 +45,7 @@ def model_carg(self, builder, manager):
                                            description=builder.attributes.get('description'),
                                            manufacturer=builder.attributes.get('manufacturer', ''),
                                            model_number=builder.attributes.get('model_number'))
-            model = DeviceModel(**device_model_attributes)
+            model = _construct_legacy_device_model(**device_model_attributes)
 
             return model
 

tests/unit/test_device.py

@@ -1,7 +1,17 @@
 from pynwb.device import Device, DeviceModel
+from pynwb.io.device import DeviceMapper
 from pynwb.testing import TestCase
 
 
+class DeviceBuilder(dict):
+
+    attributes = {
+        'description': 'device description',
+        'manufacturer': 'manufacturer',
+        'model_number': 'model_number',
+    }
+
+
 class TestDevice(TestCase):
 
     def test_init(self):
@@ -77,3 +87,21 @@ def test_init(self):
         self.assertEqual(device_model.manufacturer, 'manufacturer')
         self.assertEqual(device_model.model_number, 'model_number')
         self.assertEqual(device_model.description, 'description')
+
+
+class TestDeviceMapper(TestCase):
+
+    def test_model_carg_preserves_legacy_model_name(self):
+        builder = DeviceBuilder(model='MFC_200/250-0.66_40mm_MF2.5:FLT')
+        msg = (
+            'Device.model was detected as a string, but NWB 2.9 specifies Device.model as a link to a DeviceModel. '
+            'Remapping "MFC_200/250-0.66_40mm_MF2.5:FLT" to a new DeviceModel.'
+        )
+        with self.assertWarnsWith(UserWarning, msg):
+            device_model = DeviceMapper.model_carg(None, builder, None)
+
+        self.assertIsInstance(device_model, DeviceModel)
+        self.assertEqual(device_model.name, 'MFC_200/250-0.66_40mm_MF2.5:FLT')
+        self.assertEqual(device_model.description, 'device description')
+        self.assertEqual(device_model.manufacturer, 'manufacturer')
+        self.assertEqual(device_model.model_number, 'model_number')