fix unnecessary warning when simulation uses same node sets file as c…

…ircuit (#237)

bluepysnap/simulation.py

@@ -143,12 +143,14 @@ def simulator(self):
     def node_sets(self):
         """Returns the NodeSets object bound to the simulation."""
         try:
-            node_sets = NodeSets.from_file(self.circuit.to_libsonata.node_sets_path)
+            path = self.circuit.to_libsonata.node_sets_path
         except BluepySnapError:  # Error raised if circuit can not be instantiated
-            node_sets = NodeSets.from_dict({})
+            path = ""
 
-        if path := self.to_libsonata.node_sets_file:
-            overwritten = node_sets.update(NodeSets.from_file(path))
+        node_sets = NodeSets.from_file(path) if path else NodeSets.from_dict({})
+
+        if self.to_libsonata.node_sets_file != path:
+            overwritten = node_sets.update(NodeSets.from_file(self.to_libsonata.node_sets_file))
             _warn_on_overwritten_node_sets(overwritten)
 
         return node_sets

tests/test_simulation.py

@@ -22,8 +22,6 @@
 
 
 def test__warn_on_overwritten_node_sets():
-    test_module._warn_on_overwritten_node_sets
-
     # No warnings if no overwritten
     with warnings.catch_warnings():
         warnings.simplefilter("error")
@@ -83,6 +81,30 @@ def test_all():
     assert isinstance(rep["default"], PopulationCompartmentReport)
 
 
+def test_no_warning_when_shared_node_sets_path():
+    with copy_test_data(config="simulation_config.json") as (_, config_path):
+        circuit = test_module.Simulation(config_path).circuit
+        circuit_node_sets_path = circuit.to_libsonata.node_sets_path
+
+        # set simulation node set path = circuit node set path
+        with edit_config(config_path) as config:
+            config["node_sets_file"] = circuit_node_sets_path
+
+        # Should not raise
+        with warnings.catch_warnings():
+            warnings.simplefilter("error")
+            test_module.Simulation(config_path).node_sets
+
+        # if node_sets_file is not defined, libsonata should use the same path as the circuit
+        with edit_config(config_path) as config:
+            config.pop("node_sets_file")
+
+        # Should not raise either
+        with warnings.catch_warnings():
+            warnings.simplefilter("error")
+            test_module.Simulation(config_path).node_sets
+
+
 def test_unknown_report():
     with copy_test_data(config="simulation_config.json") as (_, config_path):
         with edit_config(config_path) as config: