split node tests into standalone files

tests/node_tests/test_value_io.py

@@ -0,0 +1,28 @@
+from backend.data_types import RecordTable
+
+
+def test_value_display():
+    from backend.nodes.value_io import ValueIO
+
+    node = ValueIO()
+    value_spec = ValueIO.INPUT_TYPES()["required"]["value"]
+    assert value_spec[0] == "FLOAT"
+    assert value_spec[1]["accepted_types"] == ["RECORD_TABLE"]
+
+    captured = []
+    ValueIO._broadcast_value_fn = lambda node_id, payload: captured.append((node_id, payload))
+    ValueIO._current_node_id = "test"
+
+    result = node.display_value(3.25)
+    assert result == (3.25,)
+    assert captured == [("test", {"value": 3.25})]
+
+    measurements = RecordTable([
+        {"quantity": "delta X", "value": 1.7e-7, "unit": "m"},
+        {"quantity": "delta Y", "value": 463, "unit": "count"},
+    ])
+    result = node.display_value(measurements, measurement="delta X")
+    assert result == (1.7e-7,)
+    assert captured[-1] == ("test", {"value": 1.7e-7, "unit": "m"})
+
+    ValueIO._broadcast_value_fn = None