Fix false-positive consider-using-with when using ``contextlib.Ex…

…itStack`` (#4665)

* Fix false-positive ``consider-using-with`` when using ``contextlib.ExitStack``

* Add ``whatsnew`` entry for #4654

* Python 3.6 needs special treatment - ``ExitStack`` did not inherit from ``_BaseExitStack`` until Python 3.7

ChangeLog

@@ -17,6 +17,11 @@ Release date: TBA
 ..
   Put bug fixes that should not wait for a new minor version here
 
+
+* Fix false-positive ``consider-using-with`` (R1732) if ``contextlib.ExitStack`` takes care of calling the ``__exit__`` method
+
+  Closes #4654
+
 * Fix a false positive for ``unused-private-member`` when mutating a private attribute
   with ``cls``
 

doc/whatsnew/2.9.rst

@@ -62,6 +62,8 @@ New checkers
 Other Changes
 =============
 
+* Fix false-positive ``consider-using-with`` (R1732) if ``contextlib.ExitStack`` takes care of calling the ``__exit__`` method
+
 * Add type annotations to pyreverse dot files
 
 * Pylint's tags are now the standard form ``vX.Y.Z`` and not ``pylint-X.Y.Z`` anymore.

pylint/checkers/refactoring/refactoring_checker.py

@@ -103,7 +103,7 @@ def get_curline_index_start():
     return False
 
 
-def _is_inside_context_manager(node):
+def _is_inside_context_manager(node: astroid.Call) -> bool:
     frame = node.frame()
     if not isinstance(
         frame, (astroid.FunctionDef, astroid.BoundMethod, astroid.UnboundMethod)
@@ -114,6 +114,23 @@ def _is_inside_context_manager(node):
     )
 
 
+def _will_be_released_automatically(node: astroid.Call) -> bool:
+    """Checks if a call that could be used in a ``with`` statement is used in an alternative
+    construct which would ensure that its __exit__ method is called."""
+    callables_taking_care_of_exit = frozenset(
+        (
+            "contextlib._BaseExitStack.enter_context",
+            "contextlib.ExitStack.enter_context",  # necessary for Python 3.6 compatibility
+        )
+    )
+    if not isinstance(node.parent, astroid.Call):
+        return False
+    func = utils.safe_infer(node.parent.func)
+    if not func:
+        return False
+    return func.qname() in callables_taking_care_of_exit
+
+
 class RefactoringChecker(checkers.BaseTokenChecker):
     """Looks for code which can be refactored
 
@@ -1299,7 +1316,9 @@ def _check_consider_using_with(self, node: astroid.Call):
                 and not isinstance(node.parent, astroid.With)
             )
         )
-        if could_be_used_in_with and not _is_inside_context_manager(node):
+        if could_be_used_in_with and not (
+            _is_inside_context_manager(node) or _will_be_released_automatically(node)
+        ):
             self.add_message("consider-using-with", node=node)
 
     def _check_consider_using_join(self, aug_assign):

tests/functional/c/consider/consider_using_with.py

@@ -154,3 +154,11 @@ def test_popen():
     _ = subprocess.Popen("sh")  # [consider-using-with]
     with subprocess.Popen("sh"):
         pass
+
+
+def test_suppress_in_exit_stack():
+    """Regression test for issue #4654 (false positive)"""
+    with contextlib.ExitStack() as stack:
+        _ = stack.enter_context(
+            open("/sys/firmware/devicetree/base/hwid,location", "r")
+        )  # must not trigger