Add tests for crash on inference of __len__

tests/regrtest_data/numpy_crash_tester/__init__.py

@@ -0,0 +1,2 @@
+"""Test package for the crash reported in #5244
+https://github.com/PyCQA/pylint/issues/5244"""

tests/regrtest_data/numpy_crash_tester/test_file.py

@@ -0,0 +1,18 @@
+"""Module docstring"""
+
+
+class MyClass:
+    """Class to test crash reported in:
+    https://github.com/PyCQA/pylint/issues/5244
+    """
+
+    def __init__(self, array):
+        self.array = array
+
+    def __len__(self):
+        """Initially reported crash crashed on this function def"""
+        return len(self.array)
+
+    def public_method(self):
+        """docstring"""
+        print(self.array)

tests/test_regr.py

@@ -168,3 +168,11 @@ def test_hang(
 ) -> None:
     with timeout(timeout_s):
         finalize_linter.check(file_names)
+
+
+def test_numpy_regression_crash(finalize_linter: PyLinter) -> None:
+    # Test for a crash on packages whose name start with `numpy`
+    # See: https://github.com/PyCQA/pylint/issues/5244
+    finalize_linter.check([join(REGR_DATA, "numpy_crash_tester/test_file.py")])
+    # Check that we do not issue any (fatal) messages
+    assert finalize_linter.msg_status == 0