Fix a crash in unnecessary-list-index-lookup when incorrectly using…

… `enumerate()` (#6604)
pylint-dev · May 13, 2022 · 5fee33f · 5fee33f
1 parent 55cacdb
commit 5fee33f
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diff --git a/ChangeLog b/ChangeLog
@@ -344,6 +344,11 @@ Release date: TBA
 
   Closes #6557
 
+* Fix a crash in ``unnecessary-list-index-lookup`` when incorrectly passing no
+  arguments to ``enumerate()``.
+
+  Closes #6603
+
 * Fix a crash when accessing ``__code__`` and assigning it to a variable.
 
   Closes #6539

diff --git a/doc/whatsnew/2.13.rst b/doc/whatsnew/2.13.rst
@@ -644,6 +644,10 @@ Other Changes
 
   Closes #6414
 
+* Fix a crash in ``unnecessary-list-index-lookup`` when incorrectly passing no
+  arguments to ``enumerate()``.
+
+  Closes #6603
 
 * Fix false positives for ``no-name-in-module`` and ``import-error`` for ``numpy.distutils``
   and ``pydantic``.

diff --git a/pylint/checkers/refactoring/refactoring_checker.py b/pylint/checkers/refactoring/refactoring_checker.py
@@ -1996,6 +1996,7 @@ def _check_unnecessary_list_index_lookup(
             not isinstance(node.iter, nodes.Call)
             or not isinstance(node.iter.func, nodes.Name)
             or not node.iter.func.name == "enumerate"
+            or not node.iter.args
             or not isinstance(node.iter.args[0], nodes.Name)
         ):
             return

diff --git a/tests/functional/u/unnecessary/unnecessary_list_index_lookup.py b/tests/functional/u/unnecessary/unnecessary_list_index_lookup.py
@@ -49,3 +49,7 @@ def process_list_again(data):
 pairs = [(0, 0)]
 for i, (a, b) in enumerate(pairs):
     print(pairs[i][0])
+
+# Regression test for https://github.com/PyCQA/pylint/issues/6603
+for i, num in enumerate():  # raises TypeError, but shouldn't crash pylint
+    pass