Main.purs

module Main where

import Prelude

import Debug.Trace (spy)
import Effect (Effect)
import Effect.Aff (attempt, launchAff_)
import Redis (createClient)

main :: Effect Unit
main = launchAff_ do
  errOrClient <- attempt $ createClient host port db
  let _ = spy "client" errOrClient
  pure unit

  where
  host = "127.0.0.1"
  port = 6379
  db = 1

Redis.js

const redis = require('redis')
exports.createClientImpl = function(host) {
    return function(port) {
        return function(db) {
            return function(onError, onSuccess) {
                const client = redis.createClient({
                    host: host,
                    port: port,
                    db: db
                })
                client.on("error", onError)
                client.on("connect", function() { onSuccess(client) })
            }
        }
    }
} 

Redis.purs

module Redis where

import Effect.Aff (Aff)
import Effect.Aff.Compat (EffectFnAff, fromEffectFnAff)

foreign import data RedisClient :: Type
foreign import createClientImpl :: String -> Int -> Int -> EffectFnAff RedisClient
createClient :: String -> Int -> Int -> Aff RedisClient
createClient host port db = fromEffectFnAff (createClientImpl host port db)