Test with cats-effect 3 IO
If you just run IO.unsafeRunSync()
in a test, it may not end and just hang. extras for hedgehog and cats-effect 3 (extras-hedgehog-cats-effect3
) can solve it.
completeThen
Use CatsEffectRunner
and completeThen
instead of unsafeRunSync()
.
import cats.effect._
import extras.hedgehog.cats.effect.CatsEffectRunner
import hedgehog._
import hedgehog.runner._
object SomeSpec extends Properties {
override def tests: List[Test] = List(
property("test with CatsEffectRunner and completeThen", testCatsEffectRunnerWithCompleteThen)
)
def testCatsEffectRunnerWithCompleteThen: Property = for {
n <- Gen.int(Range.linear(Int.MinValue, Int.MaxValue)).log("n")
} yield {
import CatsEffectRunner._
implicit val ticker: Ticker = Ticker.withNewTestContext()
val expected = n
val actual = IO(n)
actual.completeThen { actual =>
actual ==== expected
}
}
}
errorThen
If you want to test with IO
which may result in some Exception
thrown, you can use errorThen
instead of unsafeRunSync()
and Try
.
import cats.effect._
import extras.hedgehog.cats.effect.CatsEffectRunner
import hedgehog._
import hedgehog.runner._
object SomeSpec extends Properties {
override def tests: List[Test] = List(
property("test with CatsEffectRunner and errorThen", testCatsEffectRunnerWithErrorThen)
)
def testCatsEffectRunnerWithErrorThen: Property = for {
message <- Gen.string(Gen.alphaNum, Range.linear(1, 10)).log("message")
error <- Gen
.element1(
TestError.someTestError(s"Don't worry it's only a test error. $message"),
TestError.anotherTestError(s"Don't worry it's only a test error. $message")
)
.log("error")
} yield {
import CatsEffectRunner._
implicit val ticker: Ticker = Ticker.withNewTestContext()
val expected = error
val actual = IO.raiseError[Int](error)
actual.errorThen { actual =>
actual ==== expected
}
}
sealed abstract class TestError(val message: String) extends RuntimeException(message)
object TestError {
final case class SomeTestError(override val message: String) extends TestError(message)
final case class AnotherTestError(override val message: String) extends TestError(message)
def anotherTestError(message: String): TestError = AnotherTestError(message)
def someTestError(message: String): TestError = SomeTestError(message)
}
}