Inference breaks when a function returns a tuple with another function

[vitalyq]

Bug Report

🔎 Search Terms

Inference, tuple, generic, callback, higher-order function

🕗 Version & Regression Information

v4.3.2 and below (tested down to v3.3.3)

⏯ Playground Link

Playground link with relevant code

💻 Code

declare function a(): [
  <T>(arg: T) => T
]

declare function b<T, U>(a1: T, a2: [(a: T) => U]): U

b(1, [a()[0]]) // returns number, as expected
b(1, a()) // returns unknown (expected a number)

[RyanCavanaugh]

Looks like there's an incorrect inference priority being assigned here