message: Always wrap body expression of an arrow function in parens
diff: @@ -220,6 +220,11 @@ FPp.needsParens = function(assumeExpressionContext) {
  return false;
  }
  + if (parent.type === "ArrowFunctionExpression" && name === "body") {
  + // TODO does this expression start with a {?
  + return true;
  + }
  +
  switch (node.type) {
  case "UnaryExpression":
  case "SpreadElement":
  