vscode-glean: "Convert to Stateful Component" doesn't work with function expressions

// Doesn't work
const button = props => (
  <button type="submit" className={props.className}>
    {props.children}
  </button>
)

// Does work
function button(props) {
  return (
    <button type="submit" className={props.className}>
      {props.children}
    </button>
  )
}