org.scalatest.concurrent.TimeLimitedTests.scala Maven / Gradle / Ivy
/*
* Copyright 2001-2013 Artima, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.scalatest.concurrent
import org.scalatest.TestSuiteMixin
import org.scalatest.TestSuite
import TimeLimits._
import org.scalatest.Resources
import org.scalatest.time.Span
import org.scalatest.exceptions.TimeoutField
import org.scalatest.Outcome
import org.scalatest.Exceptional
import org.scalatest.exceptions.StackDepthExceptionHelper.getStackDepthFun
/**
* Trait that when mixed into a suite class establishes a time limit for its tests.
*
*
* Unfortunately this trait experienced a potentially breaking change in 3.0: previously
* this trait declared a defaultTestInterruptor val of type
* Interruptor, in 3.0 that was renamed to defaultTestSignaler
* and given type Signaler. The reason is that the default Interruptor, ThreadInterruptor,
* did not make sense on Scala.js—in fact, the entire notion of interruption did not make
* sense on Scala.js. Signaler's default is DoNotSignal, which is a better
* default on Scala.js, and works fine as a default on the JVM.
* Timeouts was left the same in 3.0, so existing code using it would
* continue to work as before, but after a deprecation period Timeouts will be
* supplanted by TimeLimits, which uses Signaler. TimeLimitedTests
* now uses TimeLimits instead of Timeouts, so if you overrode the default
* Interruptor before, you'll need to change it to the equivalent Signaler.
* And if you were depending on the default being a ThreadInterruptor, you'll need to
* override defaultTestSignaler and set it to ThreadSignaler.
*
*
*
* This trait overrides withFixture, wrapping a super.withFixture(test) call
* in a failAfter invocation, specifying a time limit obtained by invoking timeLimit
* and a Signaler by invoking defaultTestSignaler:
*
*
*
* failAfter(timeLimit) {
* super.withFixture(test)
* } (defaultTestSignaler)
*
*
*
* Note that the failAfter method executes the body of the by-name passed to it using the same
* thread that invoked failAfter. This means that the same thread will run the withFixture method
* as well as each test, so no extra synchronization is required. A second thread is used to run a timer, and if the timeout
* expires, that second thread will attempt to signal the main test thread via the defaultTestSignaler.
*
*
*
* The timeLimit field is abstract in this trait. Thus you must specify a time limit when you use it.
* For example, the following code specifies that each test must complete within 200 milliseconds:
*
*
*
* import org.scalatest.FunSpec
* import org.scalatest.concurrent.TimeLimitedTests
* import org.scalatest.time.SpanSugar._
*
* class ExampleSpec extends FunSpec with TimeLimitedTests {
*
* // Note: You may need to either write 200.millis or (200 millis), or
* // place a semicolon or blank line after plain old 200 millis, to
* // avoid the semicolon inference problems of postfix operator notation.
* val timeLimit = 200 millis
*
* describe("A time-limited test") {
* it("should succeed if it completes within the time limit") {
* Thread.sleep(100)
* }
* it("should fail if it is taking too darn long") {
* Thread.sleep(300)
* }
* }
* }
*
*
*
* If you run the above ExampleSpec, the second test will fail with the error message:
*
*
*
* The test did not complete within the specified 200 millisecond time limit.
*
*
*
* The failAfter method uses an Signaler to attempt to signal the main test thread if the timeout
* expires. The default Signaler returned by the defaultTestSignaler method is a
* DoNotSignal, which does not signal the main test thread to stop. If you wish to change this
* signaling strategy, override defaultTestSignaler to return a different Signaler. For example,
* here's how you'd change the default to ThreadSignaler, which will
* interrupt the main test thread when time is up:
*
*
*
* import org.scalatest.FunSpec
* import org.scalatest.concurrent.{ThreadSignaler, TimeLimitedTests}
* import org.scalatest.time.SpanSugar._
*
* class ExampleSignalerSpec extends FunSpec with TimeLimitedTests {
*
* val timeLimit = 200 millis
*
* override val defaultTestSignaler = ThreadSignaler
*
* describe("A time-limited test") {
* it("should succeed if it completes within the time limit") {
* Thread.sleep(100)
* }
* it("should fail if it is taking too darn long") {
* Thread.sleep(300)
* }
* }
* }
*
*
*
* Like the previous incarnation of ExampleSuite, the second test will fail with an error message that indicates
* a timeout expired. But whereas in the previous case, the Thread.sleep would be interrupted after 200 milliseconds,
* in this case it is never interrupted. In the previous case, the failed test requires a little over 200 milliseconds to run.
* In this case, because the sleep(300) is never interrupted, the failed test requires a little over 300 milliseconds
* to run.
*
*/
trait TimeLimitedTests extends TestSuiteMixin { this: TestSuite =>
/**
* A stackable implementation of withFixture that wraps a call to super.withFixture in a
* failAfter invocation.
*
* @param test the test on which to enforce a time limit
*/
abstract override def withFixture(test: NoArgTest): Outcome = {
try {
// TODO: should pass in the prettifier also
failAfterImpl(timeLimit, defaultTestSignaler, org.scalactic.Prettifier.default, test.pos, test.pos.map(getStackDepthFun(_)).getOrElse(getStackDepthFun("TimeLimits.scala", "failAfter", 2))) {
super.withFixture(test)
}
}
catch {
case e: org.scalatest.exceptions.ModifiableMessage[_] with TimeoutField =>
Exceptional(e.modifyMessage(opts => Some(Resources.testTimeLimitExceeded(e.timeout.prettyString))))
case t: Throwable =>
Exceptional(t)
}
}
/**
* The time limit, in milliseconds, in which each test in a Suite that mixes in
* TimeLimitedTests must complete.
*/
def timeLimit: Span
/**
* The default Signaler strategy used to interrupt tests that exceed their time limit.
*
*
* This trait's implementation of this method returns DoNotSignal, which does not signal/interrupt
* the main test and future thread. Override this method to change the test signaling strategy.
*
*
* @return a ThreadInterruptor
*/
val defaultTestSignaler: Signaler = DoNotSignal
}
/*
Will need to add cancelAfter to the doc comment in 2.0.
*/