`myEither.fold({ IO.unit }, { IO.effect { susFun() } }).bind()`

# arrow

[pakoito]

myEither.fold({ IO.unit }, { IO.effect { susFun() } }).bind()

[kartoffelsup]

Kinda feels wrong 😄
(not using IO because it's suspend and I only have IO.fx in the routes. Is that the correct approach?

override suspend fun authenticate(request: Tuple2<Password, Email>): Either<String, AuthenticatedUser> {
        val (providedPassword, email) = request
        val findUser: Either<String, User> = userRepository.findUserByEmail(email)
        return findUser.fold(
            ifLeft = { it.left() },
            ifRight = { dbUser ->
                val hashedPw = hashPw(providedPassword, email)
                if (dbUser.email.value == email.value && dbUser.password?.value?.contentEquals(hashedPw.payload) == true) {
                    val toUpdate = dbUser.copy(lastLogin = ZonedDateTime.now())
                    return userRepository.updateUser(toUpdate)
                        .map { AuthenticatedUser(it, null) }
                } else {
                    Either.left("Invalid credentials.")
                }
            }
        )
    }

[pakoito]

== true is unnecessary (pet peeve)

[pakoito]

the return…is it local or non-local?

[pakoito]

I would keep it local if possible

[pakoito]

so…delete the keyword return from return userRepository.updateUser

[pakoito]

otherwise ye

[pakoito]

I would move ifRight to its own function

[pakoito]

(if I can find where dbUser comes from, I guess from the class)

[kartoffelsup]

Thanks, that sounds good 🙂
dbUser is the right result of val findUser: Either<String, User> = userRepository.findUserByEmail(email)? Or what do you mean? ^^

[kartoffelsup]

Oops, yeah thanks it was actuallya non-local return.. Kinda forget sometimes when switching from Java to Kotlin that I shouldn't return inside a lambda.

[kartoffelsup]

But the == true is necessary because it's a nullable boolean, or am I missing something?

[pakoito]

nullable boolean oooh right

[kartoffelsup]

is there some sort of functional approach for a eventbus? And also available in arrow? 😄

[pakoito]

yeah, use Queue

[pakoito]

queue + sealed classes you have MVI

[kartoffelsup]

is there a doc for Queue?

[kartoffelsup]

ah found it, thank you