AsyncReturnType: TypeScript utility type

AsyncReturnType.ts

// https://www.typescriptlang.org/play?#code/C4TwDgpgBAggziAdgYwEoWAVwE6ICrgQA8eUEAHsBIgCZxQAUAdCwIbYDmcAXFK4iACUUALwA+PgIkiAUFCgB6BVACWAMyikAtq2DIAFhHrB9K+nBUdEunNH40o2DDkT1WUAArYA9lrMQAGjJKbFZkYCgAVUYTaFBIKG8NWMcjbwAbADcIBzAfPzgIYXsoTEKoE105TWCqWnpmNk4eSSFRCS9ffyIVRDUIbCixavkAfiiRqF4lROwWJnl1Gp09Q2NTc0trLCdJBycd11aTXo4ydMKgimBQ8IrDVMOoTNZ0zGhokrK4-Sr5eVI12odEY83YXF4-Da4lUfQGE3+UHGkUm02U3jmLFUGgg2WwIBOiDOHG8Rgq3ighnS6SCBxcUAABlCGZN5FCANwyLmsBAoKBqTAoYAqbyIPi85AAMUFyAYwgA3pM6bgKth3pyAL5cgVCkVixCi+BIKUyuVQRWI5Vim7qmRamTxaAAOUNEvQhzgnQKEEl+SNfJEUHdLgIkCIjqS4uN0pQYk5jqgLsQ-rQzlwcFDPvySZToiDafwhHDhEjBuTEpjyDjXITKeD6czvt8ucDdYLmeLkEjPOjMurtbdBYzhCbWhzErzbcOHYjGjLKcrcaAA

type AsyncReturnType<T extends (...args: any) => any> =
  // if T matches this signature and returns a Promise, extract U (the type of the resolved promise) and use that
  T extends (...args: any) => Promise<infer U>
    ? U
    : // or...  if T matches this signature and returns anything else, extract the return value U and use that
    T extends (...args: any) => infer U
    ? U
    : // or... if everything goes to hell, return `any`
      any;