How to get defined Arbitrary? - scala

Question

I am using ScalaTest and ScalaCheck. I wrote a custom generator and arbitrary generator as following:
import java.time.LocalDateTime
import org.scalacheck._
import org.scalatest.PropSpec
import org.scalatest.prop.Checkers
import Gen._
import Arbitrary.arbitrary
class AuthJwtSpec extends PropSpec with Checkers {
private val start = LocalDateTime.now.atZone(java.time.ZoneId.systemDefault()).toEpochSecond
private val end = LocalDateTime.now.plusDays(2).atZone(java.time.ZoneId.systemDefault()).toEpochSecond
private val pickTime = Gen.choose(start, end)
private val authUser: Arbitrary[AuthUser] =
Arbitrary {
for {
u <- arbitrary[String]
p <- arbitrary[String]
} yield AuthUser(u, p)
}
property("Generate JWT token.") {
check(Prop.forAll(authUser, pickTime) {(r1: AuthUser, r2: Long) =>
???
})
}
}
The problem is, that r1 has type Arbitrary[AuthUser] but I need AuthUser, how to get it?

Answer 1

As I see, the problem is with authUser field - it should be Gen[AuthUser], not Arbitary[AuthUser]:
import java.time.LocalDateTime
import org.scalacheck._
import org.scalatest._
import prop._
case class AuthUser(u: String, p: String)
class AuthJwtSpec extends PropSpec with Checkers with PropertyChecks {
private val start = LocalDateTime.now.atZone(java.time.ZoneId.systemDefault()).toEpochSecond
private val end = LocalDateTime.now.plusDays(2).atZone(java.time.ZoneId.systemDefault()).toEpochSecond
private val pickTime: Gen[Long] = Gen.choose(start, end)
// AuthUser should be Gen[AuthUser], not Arbitary[AuthUser]
private val authUser: Gen[AuthUser] =
for {
u <- Arbitrary.arbitrary[String]
p <- Arbitrary.arbitrary[String]
} yield AuthUser(u, p)
property("Generate JWT token.") {
val prop = Prop.forAll(authUser, pickTime) {(user: AuthUser, time: Long) =>
println(s"User: $user")
println(s"Time: $time")
// Property checks must always return true or false
true
}
check(prop)
}
}