Packages

Definition Classes: root

Definition Classes: root

_ZIO Test_ is a featherweight testing library for effectful programs.

The library imagines every spec as an ordinary immutable value, providing tremendous potential for composition. Thanks to tight integration with ZIO, specs can use resources (including those requiring disposal), have well- defined linear and parallel semantics, and can benefit from a host of ZIO combinators.

import zio.test._
import zio.Clock.nanoTime

object MyTest extends ZIOSpecDefault {
  def spec = suite("clock")(
    test("time is non-zero") {
      for {
        time <- Live.live(nanoTime)
      } yield assertTrue(time >= 0L)
    }
  )
}

Definition Classes: zio

package diff

Definition Classes: test

package internal

Definition Classes: test

package laws

The laws package provides functionality for describing laws as values.

The laws package provides functionality for describing laws as values. The fundamental abstraction is a set of ZLaws[Caps, R]. These laws model the laws that instances having a capability of type Caps are expected to satisfy. A capability Caps[_] is an abstraction describing some functionality that is common across different data types and obeys certain laws. For example, we can model the capability of two values of a type being compared for equality as follows:

trait Equal[-A] {
  def equal(a1: A, a2: A): Boolean
}

Definitions of equality are expected to obey certain laws:

Reflexivity - a1 === a1
Symmetry - a1 === a2 ==> a2 === a1
Transitivity - (a1 === a2) && (a2 === a3) ==> (a1 === a3)

These laws define what the capabilities mean and ensure that it is safe to abstract across different instances with the same capability.

Using ZIO Test, we can represent these laws as values. To do so, we define each law using one of the ZLaws constructors. For example:

val transitivityLaw = ZLaws.Laws3[Equal]("transitivityLaw") {
  def apply[A: Equal](a1: A, a2: A, a3: A): TestResult =
    ???
}

We can then combine laws using the + operator:

val reflexivityLaw: = ???
val symmetryLaw:    = ???

val equalLaws = reflexivityLaw + symmetryLaw + transitivityLaw

Laws have a run method that takes a generator of values of type A and checks that those values satisfy the laws. In addition, objects can extend ZLawful to provide an even more convenient syntax for users to check that instances satisfy certain laws.

object Equal extends Lawful[Equal]

object Hash extends Lawful[Hash]

object Ord extends Lawful[Ord]

checkAllLaws(Equal + Hash + Ord)(Gen.int)

Note that capabilities compose seamlessly because of contravariance. We can combine laws describing different capabilities to construct a set of laws requiring that instances having all of the capabilities satisfy each of the laws.

Definition Classes: test

package magnolia

Definition Classes: test

package poly

Definition Classes: test

package refined

Definition Classes: test

package render

Definition Classes: test

package results

Definition Classes: test

package scalacheck

This package provides helpers to integrate *some* ScalaCheck primitives to their ZIO equivalents.

This package provides helpers to integrate *some* ScalaCheck primitives to their ZIO equivalents. Currently available helpers:

Converting ScalaCheck Generators to ZIO Generators
Asserting a ScalaCheck Prop with ZIO
Asserting a ScalaCheck Properties with ZIO

**Generators**

This functionality converts legacy ScalaCheck generators to ZIO Test generators to support upgrading to ZIO Test without having to reimplement existing generators. To use it import this module and then call toGenZIO on any existing ScalaCheck generator. For example:

import org.scalacheck.Arbitrary

import zio._
import zio.test._
import zio.test.scalacheck._

val anyInt: Gen[Any, Int] =
  Arbitrary.arbitrary[Int].toGenZIO

**Asserting ScalaCheck Prop and Properties**

This functionality generates ZIO Assertions from either ScalaCheck Prop or Properties. This helps with integrating other libraries that provide ScalaCheck properties as helpers, i.e. cats-laws.

Prop example:

import org.scalacheck.Prop
import org.scalacheck.Test.{ Parameters => ScalaCheckParameters }

import zio._
import zio.test._
import zio.test.scalacheck._

val prop: Prop = Prop.forAll { (n: Int, m: Int) =>
  n + m == m + n
}
val resultDefault: TestResult = prop.assertZIO()

val resultWithCustomizations: TestResult =
  prop.assertZIO("My Prop Name", ScalaCheckParameters.default.withMaxSize(10))

Properties example:

import org.scalacheck.{ Prop, Properties }
import org.scalacheck.Test.{ Parameters => ScalaCheckParameters }

import zio._
import zio.test._
import zio.test.scalacheck._

object MyProperties extends Properties("MyProperties") {
  property("myProp") = Prop.forAll { (n: Int, m: Int) =>
    n + m == m + n
  }
}

* val resultDefault: TestResult = MyProperties.assertZIO()

// Beware that we can't provide a custom name here, it will be
// taken from the `Properties` name parameter
val resultWithCustomizations: TestResult =
  MyProperties.assertZIO(ScalaCheckParameters.default.withMaxSize(10))

Definition Classes: test

CheckConstructorLowPriority1

CheckConstructorLowPriority2

CheckConstructorLowPriority3

Eql

Gen

PrettyPrintVersionSpecific

ProvideSomePartiallyApplied

ProvideSomeSharedPartiallyApplied

ReporterEventRenderer

SuiteConstructorLowPriority1

SuiteConstructorLowPriority2

SuiteConstructorLowPriority3

SuiteConstructorLowPriority4

TestAnnotationRenderer

TestClockPlatformSpecific

TestConfig

TestConsole

TestConstructor

TestConstructorLowPriority1

TestConstructorLowPriority2

TestConstructorLowPriority3

ZIOSpecAbstractVersionSpecific

ZIOSpecDefault

ZIOSpecVersionSpecific

TestClock

Companion object TestClock

trait TestClock extends Clock with Restorable

TestClock makes it easy to deterministically and efficiently test effects involving the passage of time.

Instead of waiting for actual time to pass, sleep and methods implemented in terms of it schedule effects to take place at a given clock time. Users can adjust the clock time using the adjust and setTime methods, and all effects scheduled to take place on or before that time will automatically be run in order.

For example, here is how we can test ZIO#timeout using TestClock:

import zio.ZIO
import zio.test.TestClock

for {
  fiber  <- ZIO.sleep(5.minutes).timeout(1.minute).fork
  _      <- TestClock.adjust(1.minute)
  result <- fiber.join
} yield result == None

Note how we forked the fiber that sleep was invoked on. Calls to sleep and methods derived from it will semantically block until the time is set to on or after the time they are scheduled to run. If we didn't fork the fiber on which we called sleep we would never get to set the time on the line below. Thus, a useful pattern when using TestClock is to fork the effect being tested, then adjust the clock time, and finally verify that the expected effects have been performed.

For example, here is how we can test an effect that recurs with a fixed delay:

import zio.Queue
import zio.test.TestClock

for {
  q <- Queue.unbounded[Unit]
  _ <- q.offer(()).delay(60.minutes).forever.fork
  a <- q.poll.map(_.isEmpty)
  _ <- TestClock.adjust(60.minutes)
  b <- q.take.as(true)
  c <- q.poll.map(_.isEmpty)
  _ <- TestClock.adjust(60.minutes)
  d <- q.take.as(true)
  e <- q.poll.map(_.isEmpty)
} yield a && b && c && d && e

Here we verify that no effect is performed before the recurrence period, that an effect is performed after the recurrence period, and that the effect is performed exactly once. The key thing to note here is that after each recurrence the next recurrence is scheduled to occur at the appropriate time in the future, so when we adjust the clock by 60 minutes exactly one value is placed in the queue, and when we adjust the clock by another 60 minutes exactly one more value is placed in the queue.

Linear Supertypes

Restorable, Clock, Serializable, AnyRef, Any

Known Subclasses

Test

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Type Members

trait UnsafeAPI extends AnyRef
Definition Classes
Clock

Abstract Value Members

abstract def adjust(duration: zio.Duration)(implicit trace: Trace): UIO[Unit]
abstract def adjustWith[R, E, A](duration: zio.Duration)(zio: ZIO[R, E, A])(implicit trace: Trace): ZIO[R, E, A]
abstract def currentDateTime(implicit trace: Trace): UIO[OffsetDateTime]
Definition Classes
Clock
abstract def currentTime(unit: => ChronoUnit)(implicit trace: Trace, d: DummyImplicit): UIO[Long]
Definition Classes
Clock
abstract def currentTime(unit: => TimeUnit)(implicit trace: Trace): UIO[Long]
Definition Classes
Clock
abstract def instant(implicit trace: Trace): UIO[Instant]
Definition Classes
Clock
abstract def javaClock(implicit trace: Trace): UIO[java.time.Clock]
Definition Classes
Clock
abstract def localDateTime(implicit trace: Trace): UIO[LocalDateTime]
Definition Classes
Clock
abstract def nanoTime(implicit trace: Trace): UIO[Long]
Definition Classes
Clock
abstract def save(implicit trace: Trace): UIO[UIO[Unit]]
Definition Classes
Restorable
abstract def scheduler(implicit trace: Trace): UIO[Scheduler]
Definition Classes
Clock
abstract def setTime(instant: Instant)(implicit trace: Trace): UIO[Unit]
abstract def setTimeZone(zone: ZoneId)(implicit trace: Trace): UIO[Unit]
abstract def sleep(duration: => zio.Duration)(implicit trace: Trace): UIO[Unit]
Definition Classes
Clock
abstract def sleeps(implicit trace: Trace): UIO[List[Instant]]
abstract def timeZone(implicit trace: Trace): UIO[ZoneId]

Concrete Value Members

final def !=(arg0: Any): Boolean
Definition Classes
AnyRef → Any
final def ##: Int
Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean
Definition Classes
AnyRef → Any
final def asInstanceOf[T0]: T0
Definition Classes
Any
def clone(): AnyRef
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protected[lang]
Definition Classes
AnyRef
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@throws(classOf[java.lang.CloneNotSupportedException]) @native()
final def eq(arg0: AnyRef): Boolean
Definition Classes
AnyRef
def equals(arg0: AnyRef): Boolean
Definition Classes
AnyRef → Any
final def getClass(): Class[_ <: AnyRef]
Definition Classes
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@native()
def hashCode(): Int
Definition Classes
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@native()
final def isInstanceOf[T0]: Boolean
Definition Classes
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final def ne(arg0: AnyRef): Boolean
Definition Classes
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final def notify(): Unit
Definition Classes
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@native()
final def notifyAll(): Unit
Definition Classes
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@native()
final def synchronized[T0](arg0: => T0): T0
Definition Classes
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def toString(): String
Definition Classes
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def unsafe: UnsafeAPI
Definition Classes
Clock
final def wait(): Unit
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long, arg1: Int): Unit
Definition Classes
AnyRef
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@throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long): Unit
Definition Classes
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@throws(classOf[java.lang.InterruptedException]) @native()

Deprecated Value Members

def finalize(): Unit
Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.Throwable]) @Deprecated
Deprecated
(Since version 9)

Packages

TestClock

Companion object TestClock

trait TestClock extends Clock with Restorable

Type Members

Abstract Value Members

Concrete Value Members

Deprecated Value Members

Inherited from Restorable

Inherited from Clock

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

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TestClock

Companion object TestClock

trait TestClock extends Clock with Restorable

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Inherited from Restorable

Inherited from Clock

Inherited from Serializable

Inherited from AnyRef

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TestClock