An interface's generic method whose own type parameter is constrained by
the enclosing type's parameter (run<T extends TApi>(item: Item<T>)),
implemented by a plain contextually typed lambda, compiles since #2274:
the lambda takes the contextual signature's type parameters and lowers
once, erased. The merged corpus only covers unconstrained contextual
generics, so this program pins the constrained shape with a conditional
member on the argument type, explicit and inferred call type arguments,
the class-body form, and record-held receivers.
Verified against the 2026-10-23 base checkout, where the same shape
refused with SC2009 (Item<T>'s member 'api' has type 'T'), and the pi
models.ts:1159 Model<T> 'compat' shape refused the same way.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
