Refmt doesn't break the line when an extra long string occurs in switch branch

[feihong]

Here's a piece of code to reproduce:

let a = None;
let thing =
  switch (a) {
  | None => "error"
  | Some(fahrenheit) => "Unreasonably long string string string stringgggggggggggggg"
  };

Expected:

let a = None;
let thing =
  switch (a) {
  | None => "error"
  | Some(fahrenheit) => 
    "Unreasonably long string string string stringgggggggggggggg"
  };

Melange playground link