Fable MIDI test

FableMIDItest.fs

open Fable.Core
open Fable.Core.JsInterop
open Fable.Import

[<StringEnum>]
type MIDIPortType =
  | Input
  | Output

[<StringEnum>]
type MIDIPortDeviceState =
  | Disconnected
  | Connected

[<StringEnum>]
type MIDIPortConnectionState =
  | Open
  | Closed
  | Pending

type MIDIPort =
  [<Emit("$0.id")>]
  abstract Id: string with get
  [<Emit("$0.manufacturer")>]
  abstract Manufacturer: string option with get
  [<Emit("$0.name")>]
  abstract Name: string option with get
  [<Emit("$0.type")>]
  abstract Type: MIDIPortType with get
  [<Emit("$0.version")>]
  abstract Version: string option with get
  [<Emit("$0.state")>]
  abstract State: MIDIPortDeviceState with get
  [<Emit("$0.connection")>]
  abstract Connection: MIDIPortConnectionState with get
  [<Emit("$0.onstatechange")>]
  abstract OnStateChange : obj with get, set
  [<Emit("$0.open()")>]
  abstract Open : unit -> JS.Promise<MIDIPort>
  [<Emit("$0.close()")>]
  abstract Close : unit -> JS.Promise<MIDIPort>

type MIDIInput =
  inherit MIDIPort
  [<Emit("$0.onmidimessage")>]
  abstract OnMIDIMessage : obj with get, set

type MIDIOutput =
  inherit MIDIPort
  [<Emit("$0.send($1, $2)")>]
  abstract Send: (byte list*double) -> unit
  [<Emit("$0.clear()")>]
  abstract Clear: unit -> unit

type MIDIInputMap = (string*MIDIInput) list
type MIDIOutputMap = (string*MIDIOutput) list

type MIDIAccess =
  [<Emit("$0.inputs")>]
  abstract Inputs : MIDIInputMap with get
  [<Emit("$0.outputs")>]
  abstract Outputs : MIDIOutputMap with get
  [<Emit("$0.onstatechange")>]
  abstract OnStateChange : obj with get, set
  [<Emit("$0.sysexEnabled")>]
  abstract SysexEnabled : bool with get, set

type MIDIOption =
  | Sysex of bool
  | Software of bool
    
module Intern =
  [<Emit("navigator.requestMIDIAccess($0)")>]
  let requestMIDIAccess obj : JS.Promise<MIDIAccess> = jsNative

module MIDI =
  let requestAccess (options: MIDIOption list) =
    Intern.requestMIDIAccess (keyValueList CaseRules.LowerFirst options)

let onMIDISuccess (midiAccess: MIDIAccess) =
  let key, port = midiAccess.Outputs.[0]
  printfn "%A" port.Name

let onMIDIError (ex: obj) =
  printfn "Error: %s" (unbox ex?message)

let promise f = System.Func<_, _> f
let run f = (f >> U2.Case1) |> promise

(MIDI.requestAccess []).``then``(onfulfilled=run onMIDISuccess, onrejected=run onMIDIError)