org.scalatest.Stopper.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
/**
* Trait whose instances can accept a stop request and indicate whether a stop has already been requested.
*
*
* This is passed in
* to the run method of Suite, so that running suites of tests can be
* requested to stop early.
*
*
* @author Bill Venners
*/
trait Stopper {
/**
* Indicates whether a stop has been requested.
*
*
* Call this method
* to determine whether a running test should stop. The run method of any Suite, or
* code invoked by run, should periodically check the
* stop requested function. If true,
* the run method should interrupt its work and simply return.
*
*
* @return true if a stop has been requested
*/
def stopRequested: Boolean
/**
* Request that the current run stop.
*
*
* Invoking this method is like pulling the stop-request chord in a streetcar. It requests a stop, but in no
* way forces a stop. The running suite of tests decides when and how (and if) to respond to a stop request.
* ScalaTest's style traits periodically check the stopRequested method of the passed Stopper,
* and if a stop has been requested, terminates gracefully.
*
*/
def requestStop(): Unit
}
/**
* Companion object to Stopper that holds a factory method that produces a new Stopper whose
* stopRequested method returns false until after its requestStop has been
* invoked.
*/
object Stopper {
private class DefaultStopper extends Stopper {
@volatile private var stopWasRequested = false
def stopRequested: Boolean = stopWasRequested
def requestStop(): Unit = {
stopWasRequested = true
}
}
/**
* Factory method that produces a new Stopper whose
* stopRequested method returns false until after its requestStop has been
* invoked.
*
*
* The Stopper returned by this method can be safely used by multiple threads concurrently.
*
*
* @return a new default stopper
*/
def default: Stopper = new DefaultStopper
}