[ty] Promote tuple lengths based on the outer element types

[charliermarsh]

Summary

We normally infer list[tuple[int, ...]] for [(1,), (1, 2)], allowing tuples of other lengths to be added later. This tuple-size promotion applies to tuple literals; tuple types supplied by annotations or other expressions retain their existing lengths.

The check that preserves those lengths currently searches for tuples anywhere inside an element's type. This incorrectly blocks promotion when the tuple appears inside a generic type argument, a callable's return type, or a protocol member:

class Box[T]: ...

def example(box: Box[tuple[int, str]]) -> None:
    values = [(1,), (1, 2), box]
    reveal_type(values)
    # Before: list[tuple[int] | tuple[int, int] | Box[tuple[int, str]]]
    # After:  list[Box[tuple[int, str]] | tuple[int, ...]]

The Box is not a tuple, so its type argument should not prevent us from widening the two tuple literals. We replace this use of any_over_type with a check for whether the element itself may be a tuple. The check still follows aliases, unions, type-variable bounds, and NewType bases that can describe a tuple value, while skipping nested type arguments and members.

[astral-sh-bot]

Typing conformance results

No changes detected ✅

Current numbers

The percentage of diagnostics emitted that were expected errors held steady at 98.24%. The percentage of expected errors that received a diagnostic held steady at 98.24%. The number of fully passing files held steady at 134/146.

[astral-sh-bot]

Memory usage report

Summary

Project	Old	New	Diff	Outcome
flake8	38.28MB	38.28MB	-	✅
trio	92.60MB	92.58MB	-0.01% (11.88kB)	⬇️
prefect	475.17MB	475.15MB	-0.00% (14.27kB)	⬇️
sphinx	172.51MB	172.48MB	-0.02% (34.62kB)	⬇️

Significant changes

Click to expand detailed breakdown

trio

Name	Old	New	Diff	Outcome
ProtocolInterface	200.94kB	197.91kB	-1.51% (3.03kB)	⬇️
Type<'db>::apply_specialization_inner_::interned_arguments	932.27kB	930.55kB	-0.18% (1.72kB)	⬇️
CallableType	1.63MB	1.63MB	-0.09% (1.59kB)	⬇️
GenericAlias<'db>::try_mro_	735.45kB	734.12kB	-0.18% (1.34kB)	⬇️
Type<'db>::apply_specialization_inner_	654.41kB	653.21kB	-0.18% (1.20kB)	⬇️
cached_protocol_interface	73.48kB	72.53kB	-1.30% (976.00B)	⬇️
FunctionType	1.20MB	1.20MB	-0.07% (856.00B)	⬇️
function_known_decorators	330.52kB	330.24kB	-0.09% (288.00B)	⬇️
Specialization	1.05MB	1.05MB	-0.02% (240.00B)	⬇️
may_have_unbounded_specialization_inner	840.00B	656.00B	-21.90% (184.00B)	⬇️
infer_expression_types_impl	5.97MB	5.97MB	-0.00% (152.00B)	⬇️
GenericAlias	373.22kB	373.08kB	-0.04% (144.00B)	⬇️
may_have_unbounded_specialization_inner::interned_arguments	448.00B	320.00B	-28.57% (128.00B)	⬇️
infer_scope_types_impl	2.83MB	2.83MB	-0.00% (64.00B)	⬇️
infer_definition_types	4.68MB	4.68MB	-0.00% (64.00B)	⬇️
...			3 more

prefect

Name	Old	New	Diff	Outcome
ProtocolInterface	910.42kB	907.72kB	-0.30% (2.70kB)	⬇️
infer_expression_types_impl	24.05MB	24.05MB	-0.01% (1.86kB)	⬇️
CallableType	8.94MB	8.94MB	-0.02% (1.81kB)	⬇️
Type<'db>::apply_specialization_inner_::interned_arguments	4.10MB	4.10MB	-0.03% (1.33kB)	⬇️
GenericAlias<'db>::try_mro_	4.56MB	4.56MB	-0.03% (1.24kB)	⬇️
infer_definition_types	37.83MB	37.82MB	-0.00% (1.01kB)	⬇️
infer_scope_types_impl	19.67MB	19.67MB	-0.00% (1016.00B)	⬇️
Type<'db>::apply_specialization_inner_	2.96MB	2.96MB	-0.03% (912.00B)	⬇️
cached_protocol_interface	304.23kB	303.41kB	-0.27% (840.00B)	⬇️
FunctionType	5.73MB	5.73MB	-0.01% (488.00B)	⬇️
may_have_unbounded_specialization_inner	1.57kB	1.14kB	-27.36% (440.00B)	⬇️
function_known_decorators	1.82MB	1.82MB	-0.02% (304.00B)	⬇️
Specialization	4.87MB	4.87MB	-0.00% (128.00B)	⬇️
may_have_unbounded_specialization_inner::interned_arguments	960.00B	832.00B	-13.33% (128.00B)	⬇️
infer_statement_types_impl	673.79kB	673.70kB	-0.01% (88.00B)	⬇️
...			10 more

sphinx

Name	Old	New	Diff	Outcome
CallableType	2.05MB	2.04MB	-0.33% (6.87kB)	⬇️
ProtocolInterface	322.68kB	316.54kB	-1.90% (6.14kB)	⬇️
FunctionType	1.78MB	1.78MB	-0.24% (4.38kB)	⬇️
Type<'db>::apply_specialization_inner_::interned_arguments	1.16MB	1.16MB	-0.26% (3.12kB)	⬇️
GenericAlias<'db>::try_mro_	1.41MB	1.41MB	-0.19% (2.72kB)	⬇️
Type<'db>::apply_specialization_inner_	775.89kB	773.70kB	-0.28% (2.19kB)	⬇️
cached_protocol_interface	113.33kB	111.26kB	-1.83% (2.07kB)	⬇️
infer_expression_types_impl	11.66MB	11.66MB	-0.01% (1.08kB)	⬇️
Specialization	1.59MB	1.59MB	-0.06% (960.00B)	⬇️
may_have_unbounded_specialization_inner	4.01kB	3.21kB	-19.88% (816.00B)	⬇️
remove_self_inner::interned_arguments	99.70kB	99.00kB	-0.71% (720.00B)	⬇️
GenericAlias	605.67kB	605.11kB	-0.09% (576.00B)	⬇️
FunctionType<'db>::literal_signature_	1.08MB	1.08MB	-0.04% (464.00B)	⬇️
may_have_unbounded_specialization_inner::interned_arguments	2.94kB	2.50kB	-14.89% (448.00B)	⬇️
infer_deferred_types	2.05MB	2.05MB	-0.02% (408.00B)	⬇️
...			8 more

[astral-sh-bot]

ecosystem-analyzer results

No diagnostic changes detected ✅

Full report with detailed diff (timing results)