40 columns                              |
>>> do not split after "("
doSomethingWithFn((argument) => functionBodyTooLong());
<<<
doSomethingWithFn((argument) =>
    functionBodyTooLong());
>>> newline before fn expression should not force => to split
{
  () => one;
  () => two;
}
<<<
{
  () => one;
  () => two;
}