https://twitter.com/kentcdodds/status/1163509084173168640

code.js

// thanks to node throwing an error if you try to use instanceof with an arrow
// function we have to have this function. I guess it's spec... SMH...
// NOTE: I tried doing the "proper thing" using Symbol.instanceOf
// but no matter what that did, I couldn't make that work with a SyntaxError
// because SyntaxError[Symbol.hasInstance]() returns false. What. The. Heck!?
// So I'm doing this hacky try/catch garbage :-/
function instanceOf(inst, cls) {
  try {
    return inst instanceof cls
  } catch (error) {
    return false
  }
}