Type for an empty object

ReScript version: rescript@9.1.4

The type for an empty object is {.}.

This can be created using Js.Obj.empty()

Example:

let f: {.} => {..} = o => {
  Js.Obj.assign(o, {"x": 0})
}

let a = f(Js.Obj.empty()) // OK
let b = f({"y": 0}) // Error

However if we change {.} to {..}:

let f: {..} => {..} = o => {
  Js.Obj.assign(o, {"x": 0})
}

let a = f(Js.Obj.empty()) // OK
let b = f({"y": 0}) // OK