Validate node values (#3715)

* Added extra inputs/outputs variables validation at the Node level

Signed-off-by: Elena Khaustova <[email protected]>

* Fixing potential typo

Signed-off-by: Elena Khaustova <[email protected]>

* Added release note

Signed-off-by: Elena Khaustova <[email protected]>

* Retrigger the CI

Signed-off-by: Elena Khaustova <[email protected]>

---------

Signed-off-by: Elena Khaustova <[email protected]>

RELEASE.md

@@ -1,9 +1,10 @@
 # Upcoming Release 0.19.4
 
 ## Major features and improvements
+* Improved error message when passing wrong value to node.
 * Cookiecutter errors are shown in short format without the `--verbose` flag.
 * Kedro commands now work from any subdirectory within a Kedro project.
-* Kedro CLI now provides a better error message when project commands are run outside of a project i.e. `kedro run`
+* Kedro CLI now provides a better error message when project commands are run outside of a project i.e. `kedro run`.
 
 ## Bug fixes and other changes
 * Updated `kedro pipeline create` and `kedro pipeline delete` to read the base environment from the project settings.

kedro/pipeline/node.py

@@ -42,7 +42,7 @@ def __init__(  # noqa: PLR0913
                 function. When dict[str, str] is provided, variable names
                 will be mapped to function argument names.
             outputs: The name or the list of the names of variables used
-                as outputs to the function. The number of names should match
+                as outputs of the function. The number of names should match
                 the number of outputs returned by the provided function.
                 When dict[str, str] is provided, variable names will be mapped
                 to the named outputs the function returns.
@@ -67,7 +67,6 @@ def __init__(  # noqa: PLR0913
                 and/or fullstops.
 
         """
-
         if not callable(func):
             raise ValueError(
                 _node_error_message(
@@ -83,6 +82,16 @@ def __init__(  # noqa: PLR0913
                 )
             )
 
+        for _input in _to_list(inputs):
+            if not isinstance(_input, str):
+                raise ValueError(
+                    _node_error_message(
+                        f"names of variables used as inputs to the function "
+                        f"must be of 'String' type, but {_input} from {inputs} "
+                        f"is '{type(_input)}'."
+                    )
+                )
+
         if outputs and not isinstance(outputs, (list, dict, str)):
             raise ValueError(
                 _node_error_message(
@@ -91,6 +100,16 @@ def __init__(  # noqa: PLR0913
                 )
             )
 
+        for _output in _to_list(outputs):
+            if not isinstance(_output, str):
+                raise ValueError(
+                    _node_error_message(
+                        f"names of variables used as outputs of the function "
+                        f"must be of 'String' type, but {_output} from {outputs} "
+                        f"is '{type(_output)}'."
+                    )
+                )
+
         if not inputs and not outputs:
             raise ValueError(
                 _node_error_message("it must have some 'inputs' or 'outputs'.")

tests/ipython/conftest.py

@@ -111,7 +111,7 @@ def dummy_node_empty_input():
     return node(
         func=dummy_function,
         inputs=["", ""],
-        outputs=[None],
+        outputs=None,
         name="dummy_node_empty_input",
     )
 

tests/pipeline/test_node.py

@@ -252,6 +252,14 @@ def duplicate_output_list_node():
     return identity, "A", ["A", "A"]
 
 
+def bad_input_variable_name():
+    return lambda x: None, {"a": 1, "b": "B"}, {"a": "A", "b": "B"}
+
+
+def bad_output_variable_name():
+    return lambda x: None, {"a": "A", "b": "B"}, {"a": "A", "b": 2}
+
+
 @pytest.mark.parametrize(
     "func, expected",
     [
@@ -275,6 +283,11 @@ def duplicate_output_list_node():
             r"\(\[A\]\) -> \[A;A\] due to "
             r"duplicate output\(s\) {\'A\'}.",
         ),
+        (bad_input_variable_name, "names of variables used as inputs to the function "),
+        (
+            bad_output_variable_name,
+            "names of variables used as outputs of the function ",
+        ),
     ],
 )
 def test_bad_node(func, expected):