Merge eb8bafe into 7a4eab2

canals/pipeline/pipeline.py

@@ -457,6 +457,9 @@ def run(self, data: Dict[str, Any], debug: bool = False) -> Dict[str, Any]:  # p
 
         for node_name, input_data in data.items():
             for socket_name, value in input_data.items():
+                # Make a copy of the input value so components don't need to
+                # take care of mutability.
+                value = deepcopy(value)
                 connection = Connection(
                     None, None, node_name, self.graph.nodes[node_name]["input_sockets"][socket_name]
                 )

test/pipeline/integration/test_mutable_inputs.py

@@ -0,0 +1,27 @@
+from typing import List
+
+from canals import Pipeline, component
+from sample_components import StringListJoiner
+
+
+@component
+class InputMangler:
+    @component.output_types(mangled_list=List[str])
+    def run(self, input_list: List[str]):
+        input_list.append("extra_item")
+        return {"mangled_list": input_list}
+
+
+def test_mutable_inputs():
+    pipe = Pipeline()
+    pipe.add_component("mangler1", InputMangler())
+    pipe.add_component("mangler2", InputMangler())
+    pipe.add_component("concat1", StringListJoiner())
+    pipe.add_component("concat2", StringListJoiner())
+    pipe.connect("mangler1", "concat1")
+    pipe.connect("mangler2", "concat2")
+
+    mylist = ["foo", "bar"]
+
+    result = pipe.run(data={"mangler1": {"input_list": mylist}, "mangler2": {"input_list": mylist}})
+    assert result["concat1"]["output"] == result["concat1"]["output"] == ["foo", "bar", "extra_item"]