kotlin-typed-errors-1.kt

import arrow.core.Either
import arrow.core.raise.either
import arrow.core.raise.zipOrAccumulate
import arrow.core.right

data class UserPatchRequest(
    val email: String? = null,
    val password: String? = null,
    val timezone: String? = null
)

suspend fun UserPatchRequest.toUserPatch(): Either<BadRequestException, UserPatch> =
    either {
        return zipOrAccumulate(
            { email?.let { EmailAddress.validated(it).mapLeft { e -> "email" to e }.bind() } },
            { password?.let { Password.validated(it).mapLeft { e -> "password" to e }.bind() } },
            { timezone?.let { UserTimeZone.validated(it).mapLeft { e -> "timezone" to e }.bind() } }
        ) { email, password, timezone ->
            UserPatch(
                email = email,
                passwordHash = password?.let { BCryptHash.generate(it.value) },
                timezone = timezone
            ).right()
        }
    }.mapLeft { errors ->
        BadRequestException(errors.toMap())
    }