fix(types): guard against IndexError on bare List in classifier fns#1356
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devteamaegis wants to merge 1 commit into
Open
fix(types): guard against IndexError on bare List in classifier fns#1356devteamaegis wants to merge 1 commit into
devteamaegis wants to merge 1 commit into
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…r and as_classifier Both functions called get_args(typ)[0] after confirming get_origin(typ) is list, but never checked whether get_args() returned a non-empty tuple. Bare typing.List (no type parameter) produces get_args() == (), causing an immediate IndexError. is_classifier now returns False for bare List; as_classifier raises ValueError with a descriptive message directing callers to use a parameterised form.
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What's broken
Calling
is_classifier(List)oras_classifier(List)with an unparameterisedtyping.List(no type argument) raisesIndexError: tuple index out of range. Both functions checkget_origin(typ) is listand then unconditionally indexget_args(typ)[0], but bareListproducesget_args(List) == (), making the index crash immediately. AnyTaskconstructed withresult_type=Listhits this path.Why it happens
get_argsreturns an empty tuple for unparameterised generic aliases, so indexing position 0 is always an error.Fix
Added a
type_args = get_args(typ)guard before the index in both functions. Inis_classifier, an emptytype_argsreturnsFalse(bareListis not a valid classifier). Inas_classifier, it raisesValueErrorwith a message directing callers to use a parameterised form likelist[MyEnum].Test
test_is_classifier_bare_list_no_indexerrorconfirmsis_classifier(List)returnsFalseandas_classifier(List)raisesValueErrorwith the word "unparameterised", with noIndexErrorin either case.Fixes #1355