1 files changed, 71 insertions, 0 deletions
diff --git a/tests/functional/i/invalid_slice_index.py b/tests/functional/i/invalid_slice_index.py
new file mode 100644
index 000000000..1eb2fda9c
--- /dev/null
+++ b/tests/functional/i/invalid_slice_index.py
@@ -0,0 +1,71 @@
+"""Errors for invalid slice indices"""
+# pylint: disable=too-few-public-methods, no-self-use,missing-docstring,expression-not-assigned, useless-object-inheritance, unnecessary-pass
+
+
+TESTLIST = [1, 2, 3]
+
+# Invalid indices
+def function1():
+    """functions used as indices"""
+    return TESTLIST[id:id:]  # [invalid-slice-index,invalid-slice-index]
+
+def function2():
+    """strings used as indices"""
+    return TESTLIST['0':'1':]  # [invalid-slice-index,invalid-slice-index]
+
+def function3():
+    """class without __index__ used as index"""
+
+    class NoIndexTest(object):
+        """Class with no __index__ method"""
+        pass
+
+    return TESTLIST[NoIndexTest()::]  # [invalid-slice-index]
+
+# Valid indices
+def function4():
+    """integers used as indices"""
+    return TESTLIST[0:0:0] # no error
+
+def function5():
+    """None used as indices"""
+    return TESTLIST[None:None:None] # no error
+
+def function6():
+    """class with __index__ used as index"""
+    class IndexTest(object):
+        """Class with __index__ method"""
+        def __index__(self):
+            """Allow objects of this class to be used as slice indices"""
+            return 0
+
+    return TESTLIST[IndexTest():None:None] # no error
+
+def function7():
+    """class with __index__ in superclass used as index"""
+    class IndexType(object):
+        """Class with __index__ method"""
+        def __index__(self):
+            """Allow objects of this class to be used as slice indices"""
+            return 0
+
+    class IndexSubType(IndexType):
+        """Class with __index__ in parent"""
+        pass
+
+    return TESTLIST[IndexSubType():None:None] # no error
+
+def function8():
+    """slice object used as index"""
+    return TESTLIST[slice(1, 2, 3)] # no error
+
+
+def function9():
+    """Use a custom class that knows how to handle string slices"""
+    class StringSlice:
+        def __getitem__(self, item):
+            return item
+
+    StringSlice()["a":"b":"c"]
+    StringSlice()["a":"b":"c", "a":"b"]
+    StringSlice()[slice("a", "b", "c")]