Client.js

exports.mkClient = function(){
    var jsforce = require('jsforce');
    return new jsforce.Client();
}

exports.getConnection = function(client, loginProps, connectionCancel, connectionError, left, right){
    return function(onError, onSuccess) {

        function loginHandler(err, result){
            if (err != null)
                return left( connectionError( err.message ) );
            
            if (result === 'cancel')
                return left( connectionCancel );

            if (result === 'connect')
                return right( right( client ) );
        }

        client.login(loginProps, loginHandler);

        return function(cancelError, onCancelerError, onCancelerSuccess) {
            onCancelerSuccess();
        }
      
    }
    
}

Client.purs

module Client where

import Data.Either (Either(..))
import Data.Function.Uncurried
import Effect.Aff.Compat
import Types 

data ConnectionError = ConnectionCancel | ConnectionError String

type BrowserProps 
    = { width :: Int
      , height :: Int 
      }

type LoginProps 
    = { browserProps :: BrowserProps
      , scope        :: Int 
      }


foreign import mkClient :: Client 
foreign import getConnection :: Fn6 Client LoginProps ConnectionError (String -> ConnectionError) (ConnectionError -> Either ConnectionError Connection) (Connection -> Either ConnectionError Connection) (EffectFnAff (Either ConnectionError Connection)) -> EffectFnAff (Either ConnectionError Connection)