[wrong-exception-operation] Fix FP for tuple concatenation of excepti…

…on types (#9289) (#9291) (cherry picked from commit 8d4c6c1) Co-authored-by: Jacob Walls <[email protected]>
pylint-dev · Dec 10, 2023 · fea5483 · fea5483
1 parent d0d5c91
commit fea5483
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diff --git a/doc/whatsnew/fragments/9288.false_positive b/doc/whatsnew/fragments/9288.false_positive
@@ -0,0 +1,4 @@
+Fix false positive for ``invalid-exception-operation`` when concatenating tuples
+of exception types.
+
+Closes #9288
diff --git a/pylint/checkers/exceptions.py b/pylint/checkers/exceptions.py
@@ -533,8 +533,19 @@ def gather_exceptions_from_handler(
     @utils.only_required_for_messages("wrong-exception-operation")
     def visit_binop(self, node: nodes.BinOp) -> None:
         if isinstance(node.parent, nodes.ExceptHandler):
+            both_sides_tuple_or_uninferable = isinstance(
+                utils.safe_infer(node.left), (nodes.Tuple, util.UninferableBase)
+            ) and isinstance(
+                utils.safe_infer(node.right), (nodes.Tuple, util.UninferableBase)
+            )
+            # Tuple concatenation allowed
+            if both_sides_tuple_or_uninferable:
+                if node.op == "+":
+                    return
+                suggestion = f"Did you mean '({node.left.as_string()} + {node.right.as_string()})' instead?"
             # except (V | A)
-            suggestion = f"Did you mean '({node.left.as_string()}, {node.right.as_string()})' instead?"
+            else:
+                suggestion = f"Did you mean '({node.left.as_string()}, {node.right.as_string()})' instead?"
             self.add_message("wrong-exception-operation", node=node, args=(suggestion,))
 
     @utils.only_required_for_messages("wrong-exception-operation")

diff --git a/tests/functional/w/wrong_exception_operation.py b/tests/functional/w/wrong_exception_operation.py
@@ -16,3 +16,24 @@
     1/0
 except (ValueError < TypeError): # [wrong-exception-operation]
     pass
+
+
+# Concatenation of exception type tuples
+DIVISION_BY_ZERO = (ZeroDivisionError,)
+VALUE_ERROR = (ValueError,)
+UNINFERABLE = DIVISION_BY_ZERO | VALUE_ERROR
+
+try:
+    1/0
+except (ValueError, ) + DIVISION_BY_ZERO:
+    pass
+
+try:
+    1/0
+except (ValueError, ) | DIVISION_BY_ZERO:  # [wrong-exception-operation]
+    pass
+
+try:
+    1/0
+except (ValueError, ) + UNINFERABLE:
+    pass
diff --git a/tests/functional/w/wrong_exception_operation.txt b/tests/functional/w/wrong_exception_operation.txt
@@ -2,3 +2,4 @@ catching-non-exception:6:8:6:30::"Catching an exception which doesn't inherit fr
 wrong-exception-operation:6:8:6:30::Invalid exception operation. Did you mean '(ValueError, TypeError)' instead?:UNDEFINED
 wrong-exception-operation:11:8:11:30::Invalid exception operation. Did you mean '(ValueError, TypeError)' instead?:UNDEFINED
 wrong-exception-operation:17:8:17:30::Invalid exception operation. Did you mean '(ValueError, TypeError)' instead?:UNDEFINED
+wrong-exception-operation:33:7:33:40::Invalid exception operation. Did you mean '((ValueError, ) + DIVISION_BY_ZERO)' instead?:UNDEFINED