Read string types in PEP 695/696 positions, skip Literal values and Annotated metadata

[hakancelikdev]

From the core-dev review of claude/integration. Follow-up to #344 (issue #329); these cases also exist on main.

Problems

1. String forward references in new type positions were ignored, so the imports they name were removed and type checking broke:
   • type Money = "Decimal" (PEP 695)
   • def f[T: "Fraction" = "Number"](), class Box[*Ts = "Protocol"] (type-param bound and default, PEP 695/696)
   • TypeVar("T", default="Decimal"), ParamSpec("P", default=...), TypeVarTuple(..., default=...) (PEP 696)
2. Literal["os"] kept an unused import os. Literal is in SUBSCRIPT_TYPE_VARIABLE, so visit_Subscript parsed its strings before the _is_type_expression guard could run. The guard only worked for t.Literal[...].
3. Annotated[int, "Decimal"] metadata was parsed as a type by visit_Subscript in the same way.

Fix

• _is_type_expression recognizes ast.TypeAlias.value and the bound / default_value of ast.TypeVar / ParamSpec / TypeVarTuple. These nodes are looked up with getattr, since they don't exist on 3.9–3.11.
• visit_Call reads default= for all three factories. Constraints are still read for TypeVar only.
• visit_Subscript skips Literal[...] and parses only the first element of Annotated[...].

Tests

• typing/string_type_parameters (3.13+) and typing/string_literal_and_defaults are new. Both fail before this change.
• typing/function_str_arg is regenerated. It asserted the old behavior, where "Literal['Dict']" counted as a use of Dict; 'Dict' there is a literal value, so Dict is unused.
• Full suite passes on 3.9 / 3.12 / 3.14, and the cases also pass on 3.13. Pre-commit passes.

🤖 Generated with Claude Code

https://claude.ai/code/session_019P9bvuGwAyVCNUdsAYPB1V

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