Printing too many parens for lambda:

let make = (~onClick, _children) => {
  ...component,
  reducer: (action, _state) =>
    switch action {
    | Click =>
      ReasonReact.UpdateWithSideEffects(nextState, (self => Js.log("leaf onClick triggered")))
    },
  didUpdate: self => Js.log("leaf updated (didUpdate)"),
  render: self => <div onClick=(e => self.send(Click))> (string("hello")) </div>
};

/* Compare the printed to desired */
ReasonReact.UpdateWithSideEffects(nextState, (self => Js.log("leaf onClick triggered")))

ReasonReact.UpdateWithSideEffects(nextState, self => Js.log("leaf onClick triggered"))

Interestingly, when refmt prints this on its own (not inside of a switch case), it omits the parens.

We should remove these parens to reduce paren-fatigue.

Start by reproducing the two snippets with refmt, comparing the output inside a switch case with the standalone output. Trace the formatter path responsible for lambda parentheses and confirm the unnecessary parentheses are removed without changing other formatting cases.