Ensure no nodes can depend on themselves even when transcoding is used

RELEASE.md

@@ -18,6 +18,7 @@
 * Changed the path of where pipeline tests generated with `kedro pipeline create` from `<project root>/src/tests/pipelines/<pipeline name>` to `<project root>/tests/pipelines/<pipeline name>`.
 * Updated ``.gitignore`` to prevent pushing Mlflow local runs folder to a remote forge when using mlflow and git.
 * Fixed error handling message for malformed yaml/json files in OmegaConfigLoader.
+* Fixed a bug in `node`-creation allowing self-dependencies when using transcoding, that is datasets named like `name@format`.
 
 ## Breaking changes to the API
 * Methods `_is_project` and `_find_kedro_project` have been moved to `kedro.utils`. We recommend not using private methods in your code, but if you do, please update your code to use the new location.

kedro/framework/context/context.py

@@ -15,7 +15,7 @@
 from kedro.config import AbstractConfigLoader, MissingConfigException
 from kedro.framework.project import settings
 from kedro.io import DataCatalog
-from kedro.pipeline.pipeline import _transcode_split
+from kedro.pipeline._transcoding import _transcode_split
 
 
 def _is_relative_path(path_string: str) -> bool:

kedro/pipeline/_transcoding.py

@@ -0,0 +1,38 @@
+from typing import Tuple
+
+TRANSCODING_SEPARATOR = "@"
+
+
+def _transcode_split(element: str) -> Tuple[str, str]:
+    """Split the name by the transcoding separator.
+    If the transcoding part is missing, empty string will be put in.
+
+    Returns:
+        Node input/output name before the transcoding separator, if present.
+    Raises:
+        ValueError: Raised if more than one transcoding separator
+        is present in the name.
+    """
+    split_name = element.split(TRANSCODING_SEPARATOR)
+
+    if len(split_name) > 2:  # noqa: PLR2004
+        raise ValueError(
+            f"Expected maximum 1 transcoding separator, found {len(split_name) - 1} "
+            f"instead: '{element}'."
+        )
+    if len(split_name) == 1:
+        split_name.append("")
+
+    return tuple(split_name)  # type: ignore
+
+
+def _strip_transcoding(element: str) -> str:
+    """Strip out the transcoding separator and anything that follows.
+
+    Returns:
+        Node input/output name before the transcoding separator, if present.
+    Raises:
+        ValueError: Raised if more than one transcoding separator
+        is present in the name.
+    """
+    return _transcode_split(element)[0]

kedro/pipeline/modular_pipeline.py

@@ -6,12 +6,9 @@
 from typing import AbstractSet, Iterable
 
 from kedro.pipeline.node import Node
-from kedro.pipeline.pipeline import (
-    TRANSCODING_SEPARATOR,
-    Pipeline,
-    _strip_transcoding,
-    _transcode_split,
-)
+from kedro.pipeline.pipeline import Pipeline
+
+from ._transcoding import TRANSCODING_SEPARATOR, _strip_transcoding, _transcode_split
 
 
 class ModularPipelineError(Exception):

kedro/pipeline/node.py

@@ -13,6 +13,8 @@
 
 from more_itertools import spy, unzip
 
+from ._transcoding import _strip_transcoding
+
 
 class Node:
     """``Node`` is an auxiliary class facilitating the operations required to
@@ -528,11 +530,13 @@ def _validate_unique_outputs(self) -> None:
             )
 
     def _validate_inputs_dif_than_outputs(self) -> None:
-        common_in_out = set(self.inputs).intersection(set(self.outputs))
+        common_in_out = set(map(_strip_transcoding, self.inputs)).intersection(
+            set(map(_strip_transcoding, self.outputs))
+        )
         if common_in_out:
             raise ValueError(
                 f"Failed to create node {self}.\n"
-                f"A node cannot have the same inputs and outputs: "
+                f"A node cannot have the same inputs and outputs even if they are transcoded: "
                 f"{common_in_out}"
             )
 

kedro/pipeline/pipeline.py

@@ -15,42 +15,7 @@
 import kedro
 from kedro.pipeline.node import Node, _to_list
 
-TRANSCODING_SEPARATOR = "@"
-
-
-def _transcode_split(element: str) -> tuple[str, str]:
-    """Split the name by the transcoding separator.
-    If the transcoding part is missing, empty string will be put in.
-
-    Returns:
-        Node input/output name before the transcoding separator, if present.
-    Raises:
-        ValueError: Raised if more than one transcoding separator
-        is present in the name.
-    """
-    split_name = element.split(TRANSCODING_SEPARATOR)
-
-    if len(split_name) > 2:  # noqa: PLR2004
-        raise ValueError(
-            f"Expected maximum 1 transcoding separator, found {len(split_name) - 1} "
-            f"instead: '{element}'."
-        )
-    if len(split_name) == 1:
-        split_name.append("")
-
-    return tuple(split_name)  # type: ignore
-
-
-def _strip_transcoding(element: str) -> str:
-    """Strip out the transcoding separator and anything that follows.
-
-    Returns:
-        Node input/output name before the transcoding separator, if present.
-    Raises:
-        ValueError: Raised if more than one transcoding separator
-        is present in the name.
-    """
-    return _transcode_split(element)[0]
+from ._transcoding import _strip_transcoding
 
 
 class OutputNotUniqueError(Exception):

tests/pipeline/test_node.py

@@ -244,6 +244,10 @@ def input_same_as_output_node():
     return biconcat, ["A", "B"], {"a": "A"}
 
 
+def transcoded_input_same_as_output_node():
+    return identity, "A@excel", {"a": "A@csv"}
+
+
 def duplicate_output_dict_node():
     return identity, "A", {"a": "A", "b": "A"}
 
@@ -269,7 +273,11 @@ def bad_output_variable_name():
         (no_input_or_output_node, r"it must have some 'inputs' or 'outputs'"),
         (
             input_same_as_output_node,
-            r"A node cannot have the same inputs and outputs: {\'A\'}",
+            r"A node cannot have the same inputs and outputs even if they are transcoded: {\'A\'}",
+        ),
+        (
+            transcoded_input_same_as_output_node,
+            r"A node cannot have the same inputs and outputs even if they are transcoded: {\'A\'}",
         ),
         (
             duplicate_output_dict_node,

tests/pipeline/test_pipeline.py

@@ -5,13 +5,12 @@
 
 import kedro
 from kedro.pipeline import node
+from kedro.pipeline._transcoding import _strip_transcoding, _transcode_split
 from kedro.pipeline.modular_pipeline import pipeline as modular_pipeline
 from kedro.pipeline.pipeline import (
     CircularDependencyError,
     ConfirmNotUniqueError,
     OutputNotUniqueError,
-    _strip_transcoding,
-    _transcode_split,
 )
 
 

tests/pipeline/test_pipeline_with_transcoding.py

@@ -4,11 +4,11 @@
 
 import kedro
 from kedro.pipeline import node
+from kedro.pipeline._transcoding import _strip_transcoding
 from kedro.pipeline.modular_pipeline import pipeline as modular_pipeline
 from kedro.pipeline.pipeline import (
     CircularDependencyError,
     OutputNotUniqueError,
-    _strip_transcoding,
 )
 
 
@@ -191,14 +191,6 @@ def test_transcoding_loop(self):
                 ]
             )
 
-    def test_transcoding_self_reference(self):
-        with pytest.raises(CircularDependencyError, match="node1"):
-            modular_pipeline(
-                [
-                    node(identity, "A@pandas", "A@spark", name="node1"),
-                ]
-            )
-
 
 class TestComplexPipelineWithTranscoding:
     """