Promise.re

let all = Js.Promise.all;

let resolve = Js.Promise.resolve;

let reject = Js.Promise.reject;

let andThen =
    (p: Js.Promise.t('a), fn: 'a => Js.Promise.t('b)): Js.Promise.t('b) =>
  p->Js.Promise.then_(fn, _);

let map = (p: Js.Promise.t('a), fn: 'a => 'b): Js.Promise.t('b) =>
  p->Js.Promise.then_(x => x->fn->resolve, _);

let wait = (p: Js.Promise.t('a), fn: 'a => unit): unit =>
  p->Js.Promise.then_(x => x->fn->resolve, _)->ignore;

let catch = (p: Js.Promise.t('a), fn: Js.Promise.error => Js.Promise.t('a)) =>
  p->Js.Promise.catch(fn, _);