1 files changed, 99 insertions, 0 deletions
diff --git a/tests/functional/u/unnecessary/unnecessary_ellipsis.py b/tests/functional/u/unnecessary/unnecessary_ellipsis.py
new file mode 100644
index 000000000..b5a61e349
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+++ b/tests/functional/u/unnecessary/unnecessary_ellipsis.py
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+"""Emit a warning when the ellipsis constant is used and can be avoided"""
+
+# pylint: disable=missing-docstring, too-few-public-methods
+
+from typing import List, overload, Union
+
+# Ellipsis and preceding statement
+try:
+    A = 2
+except ValueError:
+    A = 24
+    ... # [unnecessary-ellipsis]
+
+def ellipsis_and_subsequent_statement():
+    ... # [unnecessary-ellipsis]
+    return 0
+
+# The parent of ellipsis is an assignment
+B = ...
+C = [..., 1, 2, 3]
+
+# The parent of ellipsis is a call
+if "X" is type(...):
+    ...
+
+def docstring_only():
+    '''In Python, stubbed functions often have a body that contains just a
+    single `...` constant, indicating that the function doesn't do
+    anything. However, a stubbed function can also have just a
+    docstring, and function with a docstring and no body also does
+    nothing.
+    '''
+
+
+# This function has no docstring, so it needs a `...` constant.
+def ellipsis_only():
+    ...
+
+
+def docstring_and_ellipsis():
+    '''This function doesn't do anything, but it has a docstring, so its
+    `...` constant is useless clutter.
+
+    NEW CHECK: unnecessary-ellipsis
+
+    This would check for stubs with both docstrings and `...`
+    constants, suggesting the removal of the useless `...`
+    constants
+    '''
+    ... # [unnecessary-ellipsis]
+
+
+class DocstringOnly:
+    '''The same goes for class stubs: docstring, or `...`, but not both.
+    '''
+
+
+# No problem
+class EllipsisOnly:
+    ...
+
+
+class DocstringAndEllipsis:
+    '''Whoops! Mark this one as bad too.
+    '''
+    ... # [unnecessary-ellipsis]
+
+
+# Function overloading
+@overload
+def summarize(data: int) -> float: ...
+
+
+@overload
+def summarize(data: str) -> str: ...
+
+
+def summarize(data):
+    if isinstance(data, str):
+        ...
+    return float(data)
+
+
+
+# Method overloading
+class MyIntegerList(List[int]):
+    @overload
+    def __getitem__(self, index: int) -> int: ...
+
+    @overload
+    def __getitem__(self, index: slice) -> List[int]: ...
+
+    def __getitem__(self, index: Union[int, slice]) -> Union[int, List[int]]:
+        if isinstance(index, int):
+            ...
+        elif isinstance(index, slice):
+            ...
+        else:
+            raise TypeError(...)