org.scalatest.Payloads.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 facilitating the inclusion of a payload in a thrown ScalaTest exception.
*
*
* This trait includes a withPayload construct
* that enables a payload object (or modified
* payload object) to be included as the payload of a thrown exception.
*
*
* Many ScalaTest events include an optional "payload" field that can be used
* to pass information to a custom reporter. This trait facilitates such customization,
* by making it easy to insert a payload into a thrown exception, such as a TestFailedException.
* The thrown exception must mix in Payload.
* ScalaTest looks for trait Payload and fires any payloads it finds in the relevant ScalaTest event
* stimulated by the exception, such as a TestFailed event stimulated by a TestFailedException.
* Here's an example in which a GUI snapshot is included as a payload when a test fails:
*
*
*
* withPayload(generateGUISnapshot()) {
* 1 + 1 should === (3)
* }
*
*
* @author Bill Venners
*/
trait Payloads {
/**
* Executes the block of code passed as the second parameter, and, if it
* completes abruptly with a ModifiablePayload exception,
* replaces the current payload contained in the exception, if any, with the one passed
* as the first parameter.
*
*
* This method allows you to insert a payload into a thrown Payload exception (such as
* a TestFailedException), so that payload can be included in events fired to a custom reporter
* that can make use of the payload.
* Here's an example in which a GUI snapshot is included as a payload when a test fails:
*
*
*
* withPayload(generateGUISnapshot()) {
* 1 + 1 should === (3)
* }
*
*
*/
def withPayload[T](payload: => Any)(fun: => T): T = {
try {
val outcome: T = fun
outcome match {
case Failed(e: org.scalatest.exceptions.ModifiablePayload[_]) if payload != null =>
Failed(e.modifyPayload((currentPayload: Option[Any]) => Some(payload))).asInstanceOf[T]
case Canceled(e: org.scalatest.exceptions.ModifiablePayload[_]) if payload != null =>
Canceled(e.modifyPayload((currentPayload: Option[Any]) => Some(payload))).asInstanceOf[T]
case _ => outcome
}
}
catch {
case e: org.scalatest.exceptions.ModifiablePayload[_] with Throwable =>
if (payload != null)
throw e.modifyPayload((currentPayload: Option[Any]) => Some(payload))
else
throw e
}
}
}
/**
* Companion object that facilitates the importing of Payloads members as
* an alternative to mixing it in. One use case is to import Payloads
* members so you can use them in the Scala interpreter.
*/
object Payloads extends Payloads