Convert VF transforms to correct type (OpenwaterHealth#179)

Virtual fit transforms were being read in as lists and not properly
converted to arrays. Fixed, and added a test that would have caught
the issue.

Author: ebrahimebrahim

src/openlifu/db/session.py

@@ -139,7 +139,7 @@ def from_dict(d:Dict):
             for target_id,(approval,transforms) in d['virtual_fit_results'].items():
                 d['virtual_fit_results'][target_id] = (
                     approval,
-                    [ArrayTransform(t_dict["matrix"], t_dict["units"]) for t_dict in transforms],
+                    [ArrayTransform(np.array(t_dict["matrix"]), t_dict["units"]) for t_dict in transforms],
                 )
         if isinstance(d['markers'], list):
             if len(d['markers'])>0 and isinstance(d['markers'][0], dict):

tests/test_database.py

@@ -360,7 +360,7 @@ def test_write_session_mismatched_id(example_database: Database, example_subject
         (["an_existing_target_id"], [0], pytest.raises(ValueError, match="provides no transforms")),
     ]
 )
-def test_write_session_with_invalid_fit_approval(
+def test_write_session_with_invalid_fit_results(
     example_database: Database,
     example_subject: Subject,
     target_ids: List[str],
@@ -384,6 +384,13 @@ def test_write_session_with_invalid_fit_approval(
     with expectation:
         example_database.write_session(example_subject, session)
 
+def test_session_arrays_read_correctly(example_session:Session):
+    """Verify that session data that is supposed to be array type is actually array type after reading from json"""
+    assert isinstance(example_session.array_transform.matrix, np.ndarray)
+    for _, (_, array_transforms) in example_session.virtual_fit_results.items():
+        for array_transform in array_transforms:
+            assert isinstance(array_transform.matrix, np.ndarray)
+
 @pytest.mark.parametrize("compact_representation", [True, False])
 def test_serialize_deserialize_session(example_session : Session, compact_representation:bool):
     reconstructed_session = example_session.from_json(example_session.to_json(compact_representation))