gistfile1.txt

function f() {
	switch (x) {
		case "1":
			<div>foo</div>
		case "2":
				return <div>
					<div>
					foo
					</div>
					<div>foo</div>
					</div>
		case "3":
					return <div>
						<div>foo</div>
						<div />
						</div>
		case "4":
						return <div>
							foo
							</div>
	}
}

This is what Yats does (when you add the parentheses), it seems Yats uses standard xml.vim to indent JSX, thus it works fine when JSX begins with a new line.

function f() {
  switch (x) {
    case "1":
      <div>foo</div>
    case "2":
      return (
        <div>
          <div>
              foo
          </div>
          <div>foo</div>                                                                                                                                      
        </div>
    )
    case "3":
      return (
        <div>
          <div>foo</div>
          <div/>
        </div>
    )
    case "4":
      return (
        <div>
            foo
        </div>
    )
  }
}