I'm working on some bindings for a Remix app and I could use some help with a functor to generate a loader module

Ah, I figured it out!

I moved the binding to json into MakeLoader and then change up how I pass the data to json.

// Remix.res
module Loader = {
  type t<'a> = unit => promise<'a>
}

module type LoaderData = {
  type t
}

module MakeLoader = (Data: LoaderData) => {
  type t = Loader.t<Data.t>

  @module("@remix-run/react") external json: Data.t => 'b = "json"

  @module("@remix-run/react")
  external useLoaderData: unit => Data.t = "useLoaderData"
}

// _index.res
module Data = {
  type t = {"foo": string, "data": array<string>}
}

module Loader = Remix.MakeLoader(Data)

let loader: Loader.t = async () => {
  let data = async () =>
    {
      "foo": "bar",
      "data": await Promise.resolve(["one"]),
    }

  Loader.json(await data()) // type error if this doesn't match Data.t
}

@react.component
let make = () => {
  let data = Loader.useLoaderData() // type here is Data.t
  <>
    <Home_hero />
  </>
}