Merge pull request #31 from DiamondLightSource/empty-list-parameters

Correctly handle parameters with empty lists as values

src/odin_fastcs/util.py

@@ -63,10 +63,13 @@ def _walk_odin_metadata(
     for node_name, node_value in tree.items():
         node_path = path + [node_name]
 
+        # Branches - dict or list[dict] to recurse through
         if isinstance(node_value, dict) and not is_metadata_object(node_value):
             yield from _walk_odin_metadata(node_value, node_path)
-        elif isinstance(node_value, list) and all(
-            isinstance(m, dict) for m in node_value
+        elif (
+            isinstance(node_value, list)
+            and node_value  # Exclude parameters with an empty list as a value
+            and all(isinstance(m, dict) for m in node_value)
         ):
             for idx, sub_node in enumerate(node_value):
                 sub_node_path = node_path + [str(idx)]

tests/input/one_node_fp_response.json

@@ -187,4 +187,4 @@
             }
         }
     }
-}
+}

tests/test_introspection.py

@@ -15,15 +15,15 @@ def test_one_node():
         response = json.loads(f.read())
 
     parameters = create_odin_parameters(response)
-    assert len(parameters) == 96
+    assert len(parameters) == 97
 
 
 def test_two_node():
     with (HERE / "input/two_node_fp_response.json").open() as f:
         response = json.loads(f.read())
 
     parameters = create_odin_parameters(response)
-    assert len(parameters) == 188
+    assert len(parameters) == 190
 
 
 @pytest.mark.asyncio
@@ -41,3 +41,29 @@ async def get_plugins(idx: int):
     controller = FrameProcessorAdapterController(mock_connection, parameters, "prefix")
     await controller.initialise()
     assert all(fpx in controller.get_sub_controllers() for fpx in ("FP0", "FP1"))
+
+
+def test_node_with_empty_list_is_correctly_counted():
+    parameters = create_odin_parameters({"test": []})
+    names = [p.name for p in parameters]
+    assert "test" in names
+    assert len(parameters) == 1
+
+
+def test_node_that_has_metadata_only_counts_once():
+    data = {"count": {"value": 1, "writeable": False, "type": "int"}}
+    parameters = create_odin_parameters(data)
+    assert len(parameters) == 1
+
+
+def test_nested_node_gives_correct_name():
+    data = {"top": {"nest-1": {"nest-2": 1}}}
+    parameters = create_odin_parameters(data)
+    assert len(parameters) == 1
+    assert parameters[0].name == "top_nest-1_nest-2"
+
+
+def test_config_node_splits_list_into_mutiples():
+    data = {"config": {"param": [1, 2]}}
+    parameters = create_odin_parameters(data)
+    assert len(parameters) == 2