Function with no return type passes with type signature

[kaleidawave]

The following currently emits no diagnostics

function func(): number {}

playground link

The problem being that the only time return types are checked are around return statements. Not implicit undefined returns.

This should be fairly simple to fix. But there is probably a bit more to think about in terms of where and how the diagnostic is emitted. For example for the following

function func(): number {
  if (Math.random() > 0.8) return 2;
  else {
     something.here();
  }
}

Maybe the diagnostic should be on the else clause?

There are similar conditions for while etc