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    Definition Classes
    root
  • package org
    Definition Classes
    root
  • package scalatest

    ScalaTest's main traits, classes, and other members, including members supporting ScalaTest's DSL for the Scala interpreter.

    ScalaTest's main traits, classes, and other members, including members supporting ScalaTest's DSL for the Scala interpreter.

    Definition Classes
    org
  • package concurrent

    Classes, traits, and objects related to testing asynchronous and multi-threaded behavior.

    Classes, traits, and objects related to testing asynchronous and multi-threaded behavior.

    This package is released as part of the scalatest-core module.

    Definition Classes
    scalatest
  • trait Futures extends PatienceConfiguration

    Trait that facilitates testing with futures.

    Trait that facilitates testing with futures.

    This trait defines a FutureConcept trait that can be used to implicitly wrap different kinds of futures, thereby providing a uniform testing API for futures. The three ways this trait enables you to test futures are:

    1. Invoking isReadyWithin, to assert that a future is ready within a a specified time period. Here's an example:

    assert(result.isReadyWithin(100 millis))
    

    2. Invoking futureValue, to obtain a futures result within a specified or implicit time period, like this:

    assert(result.futureValue === 7)
    
    // Or, if you expect the future to fail: assert(result.failed.futureValue.isInstanceOf[ArithmeticException])

    3. Passing the future to whenReady, and performing assertions on the result value passed to the given function, as in:

    whenReady(result) { s =>
      s should be ("hello")
    }
    

    The whenReady construct periodically inspects the passed future, until it is either ready or the configured timeout has been surpassed. If the future becomes ready before the timeout, whenReady passes the future's value to the specified function.

    To make whenReady more broadly applicable, the type of future it accepts is a FutureConcept[T], where T is the type of value promised by the future. Passing a future to whenReady requires an implicit conversion from the type of future you wish to pass (the modeled type) to FutureConcept[T]. Subtrait JavaFutures provides an implicit conversion from java.util.concurrent.Future[T] to FutureConcept[T].

    For example, the following invocation of whenReady would succeed (not throw an exception):

    import org.scalatest._
    import Matchers._
    import concurrent.Futures._
    import java.util.concurrent._
    
    val exec = Executors.newSingleThreadExecutor val task = new Callable[String] { def call() = { Thread.sleep(50); "hi" } } whenReady(exec.submit(task)) { s => s should be ("hi") }

    However, because the default timeout is 150 milliseconds, the following invocation of whenReady would ultimately produce a TestFailedException:

    val task = new Callable[String] { def call() = { Thread.sleep(500); "hi" } }
    whenReady(exec.submit(task)) { s =>
      s should be ("hi")
    }
    

    Assuming the default configuration parameters, a timeout of 150 milliseconds and an interval of 15 milliseconds, were passed implicitly to whenReady, the detail message of the thrown TestFailedException would look like:

    The future passed to whenReady was never ready, so whenReady timed out. Queried 95 times, sleeping 10 milliseconds between each query.

    Configuration of whenReady

    The whenReady methods of this trait can be flexibly configured. The two configuration parameters for whenReady along with their default values and meanings are described in the following table:

    Configuration Parameter Default Value Meaning
    timeout scaled(150 milliseconds) the maximum amount of time to allow unsuccessful queries before giving up and throwing TestFailedException
    interval scaled(15 milliseconds) the amount of time to sleep between each query

    The default values of both timeout and interval are passed to the scaled method, inherited from ScaledTimeSpans, so that the defaults can be scaled up or down together with other scaled time spans. See the documentation for trait ScaledTimeSpans for more information.

    The whenReady methods of trait Futures each take a PatienceConfig object as an implicit parameter. This object provides values for the two configuration parameters. Trait Futures provides an implicit val named defaultPatience with each configuration parameter set to its default value. If you want to set one or more configuration parameters to a different value for all invocations of whenReady in a suite you can override this val (or hide it, for example, if you are importing the members of the Futures companion object rather than mixing in the trait). For example, if you always want the default timeout to be 2 seconds and the default interval to be 5 milliseconds, you can override defaultPatience, like this:

    implicit override val defaultPatience =
      PatienceConfig(timeout = Span(2, Seconds), interval = Span(5, Millis))
    

    Or, hide it by declaring a variable of the same name in whatever scope you want the changed values to be in effect:

    implicit val defaultPatience =
      PatienceConfig(timeout =  Span(2, Seconds), interval = Span(5, Millis))
    

    In addition to taking a PatienceConfig object as an implicit parameter, the whenReady methods of trait Futures include overloaded forms that take one or two PatienceConfigParam objects that you can use to override the values provided by the implicit PatienceConfig for a single whenReady invocation. For example, if you want to set timeout to 6 seconds for just one particular whenReady invocation, you can do so like this:

    whenReady (exec.submit(task), timeout(Span(6, Seconds))) { s =>
      s should be ("hi")
    }
    

    This invocation of eventually will use 6000 for timeout and whatever value is specified by the implicitly passed PatienceConfig object for the interval configuration parameter. If you want to set both configuration parameters in this way, just list them separated by commas:

    whenReady (exec.submit(task), timeout(Span(6, Seconds)), interval(Span(500, Millis))) { s =>
      s should be ("hi")
    }
    

    You can also import or mix in the members of SpanSugar if you want a more concise DSL for expressing time spans:

    whenReady (exec.submit(task), timeout(6 seconds), interval(500 millis)) { s =>
      s should be ("hi")
    }
    

    Note: The whenReady construct was in part inspired by the whenDelivered matcher of the BlueEyes project, a lightweight, asynchronous web framework for Scala.

    Definition Classes
    concurrent
  • FutureConcept
  • PatienceConfig

trait FutureConcept[T] extends AnyRef

Concept trait for futures, instances of which are passed to the whenReady methods of trait Futures.

See the documentation for trait Futures for the details on the syntax this trait provides for testing with futures.

Self Type
FutureConcept[T]
Source
Futures.scala
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Abstract Value Members

  1. abstract def eitherValue: Option[Either[Throwable, T]]

    Queries this future for its value.

    Queries this future for its value.

    If the future is not ready, this method will return None. If ready, it will either return an exception or a T.

  2. abstract def isCanceled: Boolean

    Indicates whether this future has been canceled.

    Indicates whether this future has been canceled.

    If the underlying future does not support the concept of cancellation, this method must always return false.

  3. abstract def isExpired: Boolean

    Indicates whether this future has expired (timed out).

    Indicates whether this future has expired (timed out).

    The timeout detected by this method is different from the timeout supported by whenReady. This timeout is a timeout of the underlying future. If the underlying future does not support timeouts, this method must always return false.

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##: Int
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    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  5. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
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    @throws(classOf[java.lang.CloneNotSupportedException]) @native()
  6. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  7. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  8. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
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    Annotations
    @throws(classOf[java.lang.Throwable])
  9. def futureValue(implicit config: Futures.PatienceConfig, pos: Position): T

    Returns the result of this FutureConcept, once it is ready, or throws either the exception returned by the future (i.e., futureValue returned a Left) or TestFailedException.

    Returns the result of this FutureConcept, once it is ready, or throws either the exception returned by the future (i.e., futureValue returned a Left) or TestFailedException.

    This trait's implementation of this method queries the future repeatedly until it either is ready, or a configured maximum amount of time has passed, sleeping a configured interval between attempts; and when ready, returns the future's value. For greater efficiency, implementations of this trait may override this method so that it blocks the specified timeout while waiting for the result, if the underlying future supports this.

    The maximum amount of time to wait for the future to become ready before giving up and throwing TestFailedException is configured by the timeout field of the PatienceConfig passed implicitly as the last parameter. The interval to sleep between queries of the future (used only if the future is polled) is configured by the interval field of the PatienceConfig passed implicitly as the last parameter.

    If the eitherValue method of the underlying Scala future returns a scala.Some containing a scala.util.Failure containing a java.util.concurrent.ExecutionException, and this exception contains a non-null cause, that cause will be included in the TestFailedException as its cause. The ExecutionException will be be included as the TestFailedException's cause only if the ExecutionException's cause is null.

    config

    a PatienceConfig object containing timeout and interval parameters that are unused by this method

    returns

    the result of the future once it is ready, if value is defined as a Right

    Exceptions thrown

    TestFailedException if the future is cancelled, expires, or is still not ready after the specified timeout has been exceeded

    Throwable if once ready, the value of this future is defined as a Left (in this case, this method throws that same exception)

  10. final def futureValue(interval: Interval)(implicit config: Futures.PatienceConfig, pos: Position): T

    Returns the result of this FutureConcept, once it is ready, or throws either the exception returned by the future (i.e., eitherValue returned a Left) or TestFailedException.

    Returns the result of this FutureConcept, once it is ready, or throws either the exception returned by the future (i.e., eitherValue returned a Left) or TestFailedException.

    The maximum amount of time to wait for the future to become ready before giving up and throwing TestFailedException is configured by the timeout field of the PatienceConfig passed implicitly as the last parameter. The interval to sleep between queries of the future (used only if the future is polled) is configured by the value contained in the passed interval parameter.

    This method invokes the overloaded futureValue form with only one (implicit) argument list that contains only one argument, a PatienceConfig, passing a new PatienceConfig with the Interval specified as interval and the Timeout specified as config.timeout.

    If the eitherValue method of the underlying Scala future returns a scala.Some containing a scala.util.Failure containing a java.util.concurrent.ExecutionException, and this exception contains a non-null cause, that cause will be included in the TestFailedException as its cause. The ExecutionException will be be included as the TestFailedException's cause only if the ExecutionException's cause is null.

    interval

    the Interval configuration parameter

    config

    an PatienceConfig object containing timeout and interval parameters that are unused by this method

    returns

    the result of the future once it is ready, if value is defined as a Right

    Exceptions thrown

    TestFailedException if the future is cancelled, expires, or is still not ready after the specified timeout has been exceeded

    Throwable if once ready, the value of this future is defined as a Left (in this case, this method throws that same exception)

  11. final def futureValue(timeout: Timeout)(implicit config: Futures.PatienceConfig, pos: Position): T

    Returns the result of this FutureConcept, once it is ready, or throws either the exception returned by the future (i.e., value returned a Left) or TestFailedException.

    Returns the result of this FutureConcept, once it is ready, or throws either the exception returned by the future (i.e., value returned a Left) or TestFailedException.

    The maximum amount of time to wait for the future to become ready before giving up and throwing TestFailedException is configured by the value contained in the passed timeout parameter. The interval to sleep between queries of the future (used only if the future is polled) is configured by the interval field of the PatienceConfig passed implicitly as the last parameter.

    This method invokes the overloaded futureValue form with only one (implicit) argument list that contains only one argument, a PatienceConfig, passing a new PatienceConfig with the Timeout specified as timeout and the Interval specified as config.interval.

    If the eitherValue method of the underlying Scala future returns a scala.Some containing a scala.util.Failure containing a java.util.concurrent.ExecutionException, and this exception contains a non-null cause, that cause will be included in the TestFailedException as its cause. The ExecutionException will be be included as the TestFailedException's cause only if the ExecutionException's cause is null.

    timeout

    the Timeout configuration parameter

    config

    an PatienceConfig object containing timeout and interval parameters that are unused by this method

    returns

    the result of the future once it is ready, if eitherValue is defined as a Right

    Exceptions thrown

    TestFailedException if the future is cancelled, expires, or is still not ready after the specified timeout has been exceeded

    Throwable if once ready, the eitherValue of this future is defined as a Left (in this case, this method throws that same exception)

  12. final def futureValue(timeout: Timeout, interval: Interval)(implicit pos: Position): T

    Returns the result of this FutureConcept, once it is ready, or throws either the exception returned by the future (i.e., value returned a Left) or TestFailedException.

    Returns the result of this FutureConcept, once it is ready, or throws either the exception returned by the future (i.e., value returned a Left) or TestFailedException.

    The maximum amount of time to wait for the future to become ready before giving up and throwing TestFailedException is configured by the value contained in the passed timeout parameter. The interval to sleep between queries of the future (used only if the future is polled) is configured by the value contained in the passed interval parameter.

    This method invokes the overloaded futureValue form with only one (implicit) argument list that contains only one argument, a PatienceConfig, passing a new PatienceConfig with the Timeout specified as timeout and the Interval specified as interval.

    If the eitherValue method of the underlying Scala future returns a scala.Some containing a scala.util.Failure containing a java.util.concurrent.ExecutionException, and this exception contains a non-null cause, that cause will be included in the TestFailedException as its cause. The ExecutionException will be be included as the TestFailedException's cause only if the ExecutionException's cause is null.

    timeout

    the Timeout configuration parameter

    interval

    the Interval configuration parameter

    returns

    the result of the future once it is ready, if value is defined as a Right

    Exceptions thrown

    TestFailedException if the future is cancelled, expires, or is still not ready after the specified timeout has been exceeded

    Throwable if once ready, the value of this future is defined as a Left (in this case, this method throws that same exception)

  13. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
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    @native()
  14. def hashCode(): Int
    Definition Classes
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    @native()
  15. final def isInstanceOf[T0]: Boolean
    Definition Classes
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  16. final def isReadyWithin(timeout: Span)(implicit config: Futures.PatienceConfig, pos: Position): Boolean

    Indicates whether this future is ready within the specified timeout.

    Indicates whether this future is ready within the specified timeout.

    If the eitherValue method of the underlying Scala future returns a scala.Some containing a scala.util.Failure containing a java.util.concurrent.ExecutionException, and this exception contains a non-null cause, that cause will be included in the TestFailedException as its cause. The ExecutionException will be be included as the TestFailedException's cause only if the ExecutionException's cause is null.

  17. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  18. final def notify(): Unit
    Definition Classes
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    @native()
  19. final def notifyAll(): Unit
    Definition Classes
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    @native()
  20. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  21. def toString(): String
    Definition Classes
    AnyRef → Any
  22. final def wait(): Unit
    Definition Classes
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    Annotations
    @throws(classOf[java.lang.InterruptedException])
  23. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
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    Annotations
    @throws(classOf[java.lang.InterruptedException])
  24. final def wait(arg0: Long): Unit
    Definition Classes
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    @throws(classOf[java.lang.InterruptedException]) @native()

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