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Retries.scala
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/*
* 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
import org.scalatest.concurrent.SleepHelper
import org.scalatest.concurrent.SleepHelper
import org.scalatest.concurrent.SleepHelper
import time.Span
/**
* Provides methods that can be used in <code>withFixture</code> implementations to retry tests in various scenarios.
*
* <p>
* Trait <code>Retries</code> is intended to help you deal with “flickers”—tests that usually pass, but
* occasionally fail. The best way to deal with such tests is to fix them so they always pass. Sometimes, however, this is
* not practical. In such cases, flickers can waste your time by forcing you to investigate test failures that turn
* out to be flickers. Or worse, like the boy who cried wolf, the flickers may train you an your colleagues to not pay attention
* to failures such that you don't notice real problems, at least not in a timely manner.
* </p>
*
* <p>
* Trait <code>Retries</code> offers methods that will retry a failed and/or canceled test once, on the same thread,
* with or without a delay. These methods take a block that results in <a href="Outcome.html"><code>Outcome</code></a>,
* and are intended to be used in <code>withFixture</code> methods. You should be very selective about which tests you
* retry, retrying those for which you have good evidence to conclude they are flickers. Thus it is recommended you
* only retry tests that are tagged with <code>Retryable</code>, and only tag tests as such once they have flickered
* consistently for a while, and only after you invested a reasonable effort into fixing them properly.
* </p>
*
* <p>
* Here's an example showing how you might use <code>Retries</code>:
* </p>
*
* <pre class="stHighlighted">
* <span class="stReserved">package</span> org.scalatest.examples.tagobjects.retryable
* <br/><span class="stReserved">import</span> org.scalatest._
* <span class="stReserved">import</span> tagobjects.Retryable
* <br/><span class="stReserved">class</span> <span class="stType">SetSpec</span> <span class="stReserved">extends</span> <span class="stType">FlatSpec</span> <span class="stReserved">with</span> <span class="stType">Retries</span> {
* <br/> <span class="stReserved">override</span> <span class="stReserved">def</span> withFixture(test: <span class="stType">NoArgTest</span>) = {
* <span class="stReserved">if</span> (isRetryable(test))
* withRetry { <span class="stReserved">super</span>.withFixture(test) }
* <span class="stReserved">else</span>
* <span class="stReserved">super</span>.withFixture(test)
* }
* <br/> <span class="stQuotedString">"An empty Set"</span> should <span class="stQuotedString">"have size 0"</span> taggedAs(<span class="stType">Retryable</span>) in {
* assert(Set.empty.size === <span class="stLiteral">0</span>)
* }
* }
* </pre>
*/
trait Retries {
/**
* Retries the given block immediately (with no delay) if the <a href="Outcome.html"><code>Outcome</code></a> of executing
* the block is either <a href="Failed.html"><code>Failed</code></a> or <a href="Canceled.html"><code>Canceled</code></a>.
*
* <p>
* The behavior of this method is defined in the table below. The first two rows show the main "retry" behavior: if
* executing the block initially fails, and on retry it succeeds, the result is <code>Canceled</code>. The purpose of this is
* to deal with "flickering" tests by downgrading a failure that succeeds on retry to a cancelation.
* Or, if executing the block initially results in <code>Canceled</code>, and on retry it succeeds, the result
* is <code>Succeeded</code>. The purpose of this is to deal with tests that intermittently cancel by ignoring a cancelation that
* succeeds on retry.
* </p>
*
* <p>
* In the table below, if the “Retry <code>Outcome</code>” has just a dash, the block is not retried.
* Otherwise, the block is retried on the same thread, with no delay.
* </p>
*
* <table style="border-collapse: collapse; border: 1px solid black">
* <tr><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>First <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Retry <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Result</strong></th></tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code> (the <code>Succeeded</code> and <code>Failed</code> are
* discarded; the exception from the <code>Failed</code> is the cause of the exception in the <code>Canceled</code>)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the first <code>Failed</code> (the second <code>Failed</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Pending</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the first <code>Canceled</code> (the second <code>Canceled</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Canceled</code> (the <code>Pending</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* </table>
*
* @param blk the block to execute and potentially retry
*/
def withRetry(blk: => Outcome): Outcome = withRetry(Span.Zero)(blk)
/**
* Retries the given block with a given delay if the <a href="Outcome.html"><code>Outcome</code></a> of executing
* the block is either <a href="Failed.html"><code>Failed</code></a> or <a href="Canceled.html"><code>Canceled</code></a>.
*
* <p>
* The behavior of this method is defined in the table below. The first two rows show the main "retry" behavior: if
* executing the block initially fails, and on retry it succeeds, the result is <code>Canceled</code>. The purpose of this is
* to deal with "flickering" tests by downgrading a failure that succeeds on retry
* to a cancelation.
* Or, if executing the block initially results in <code>Canceled</code>, and on retry it succeeds, the result
* is <code>Succeeded</code>. The purpose of this is to deal with tests that intermittently cancel by ignoring a cancelation that
* succeeds on retry.
* </p>
*
* <p>
* In the table below, if the “Retry <code>Outcome</code>” has just a dash, the block is not retried.
* Otherwise, the block is retried on the same thread, after sleeping the given delay.
* </p>
*
* <table style="border-collapse: collapse; border: 1px solid black">
* <tr><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>First <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Retry <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Result</strong></th></tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code> (the <code>Succeeded</code> and <code>Failed</code> are
* discarded; the exception from the <code>Failed</code> is the cause of the exception in the <code>Canceled</code>)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the first <code>Failed</code> (the second <code>Failed</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Pending</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the first <code>Canceled</code> (the second <code>Canceled</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Canceled</code> (the <code>Pending</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* </table>
*
* @param delay the amount of time to sleep before retrying
* @param blk the block to execute and potentially retry
*/
def withRetry(delay: Span)(blk: => Outcome): Outcome = {
val firstOutcome = blk
firstOutcome match {
case Failed(ex) =>
blk match {
case Succeeded => Canceled(Resources.testFlickered, ex)
case other => firstOutcome
}
case Canceled(ex) =>
blk match {
case Succeeded => Succeeded
case failed: Failed => failed // Never hide a failure.
case other => firstOutcome
}
case other => other
}
}
/**
* Retries the given block immediately (with no delay) if the <a href="Outcome.html"><code>Outcome</code></a> of executing
* the block is <a href="Failed.html"><code>Failed</code></a>.
*
* <p>
* The behavior of this method is defined in the table below. The first row shows the main "retry" behavior: if
* executing the block initially fails, and on retry it succeeds, the result is <code>Canceled</code>. The purpose of this is
* to deal with "flickering" tests by downgrading a failure that succeeds on retry
* to a cancelation.
* </p>
*
* <p>
* In the table below, if the “Retry <code>Outcome</code>” has just a dash, the block is not retried.
* Otherwise, the block is retried on the same thread, with no delay.
* </p>
*
* <table style="border-collapse: collapse; border: 1px solid black">
* <tr><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>First <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Retry <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Result</strong></th></tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code> (the <code>Succeeded</code> and <code>Failed</code> are
* discarded; the exception from the <code>Failed</code> is the cause of the exception in the <code>Canceled</code>)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Canceled</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the first <code>Failed</code> (the second <code>Failed</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Pending</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* </table>
*
* @param blk the block to execute and potentially retry
*/
def withRetryOnFailure(blk: => Outcome): Outcome = withRetryOnFailure(Span.Zero)(blk)
/**
* Retries the given block immediately with the given delay if the <a href="Outcome.html"><code>Outcome</code></a> of executing
* the block is <a href="Failed.html"><code>Failed</code></a>.
*
* <p>
* The behavior of this method is defined in the table below. The first row shows the main "retry" behavior: if
* executing the block initially fails, and on retry it succeeds, the result is <code>Canceled</code>. The purpose of this is
* to deal with "flickering" tests by downgrading a failure that succeeds on retry
* to a cancelation.
* </p>
*
* <p>
* In the table below, if the “Retry <code>Outcome</code>” has just a dash, the block is not retried.
* Otherwise, the block is retried on the same thread, after the given delay.
* </p>
*
* <table style="border-collapse: collapse; border: 1px solid black">
* <tr><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>First <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Retry <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Result</strong></th></tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code> (the <code>Succeeded</code> and <code>Failed</code> are
* discarded; the exception from the <code>Failed</code> is the cause of the exception in the <code>Canceled</code>)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Canceled</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the first <code>Failed</code> (the second <code>Failed</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Pending</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* </table>
*
* @param delay the amount of time to sleep before retrying
* @param blk the block to execute and potentially retry
*/
def withRetryOnFailure(delay: Span)(blk: => Outcome): Outcome = {
val firstOutcome = blk
firstOutcome match {
case Failed(ex) =>
if (delay != Span.Zero)
SleepHelper.sleep(delay.millisPart)
blk match {
case Succeeded => Canceled(Resources.testFlickered, ex)
case other => firstOutcome
}
case other => other
}
}
/**
* Retries the given block immediately (with no delay) if the <a href="Outcome.html"><code>Outcome</code></a> of executing
* the block is <a href="Canceled.html"><code>Canceled</code></a>.
*
* <p>
* The behavior of this method is defined in the table below. The first row shows the main "retry" behavior: if
* executing the block initially results in <code>Canceled</code>, and on retry it succeeds, the result is <code>Succeeded</code>.
* The purpose of this is to deal with tests that intermittently cancel by ignoring a cancelation that
* succeeds on retry.
* </p>
*
* <p>
* In the table below, if the “Retry <code>Outcome</code>” has just a dash, the block is not retried.
* Otherwise, the block is retried on the same thread, with no delay.
* </p>
*
* <table style="border-collapse: collapse; border: 1px solid black">
* <tr><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>First <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Retry <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Result</strong></th></tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Succeeded</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the first <code>Canceled</code> (the second <code>Canceled</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Canceled</code> (the <code>Pending</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* </table>
*
* @param blk the block to execute and potentially retry
*/
def withRetryOnCancel(blk: => Outcome): Outcome = withRetryOnCancel(Span.Zero)(blk)
/**
* Retries the given block after the given delay if the <a href="Outcome.html"><code>Outcome</code></a> of executing
* the block is <a href="Canceled.html"><code>Canceled</code></a>.
*
* <p>
* The behavior of this method is defined in the table below. The first row shows the main "retry" behavior: if
* executing the block initially results in <code>Canceled</code>, and on retry it succeeds, the result is <code>Succeeded</code>.
* The purpose of this is to deal with tests that intermittently cancel by ignoring a cancelation that
* succeeds on retry.
* </p>
*
* <p>
* In the table below, if the “Retry <code>Outcome</code>” has just a dash, the block is not retried.
* Otherwise, the block is retried on the same thread, after the given delay.
* </p>
*
* <table style="border-collapse: collapse; border: 1px solid black">
* <tr><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>First <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Retry <code>Outcome</code></strong></th><th style="background-color: #CCCCCC; border-width: 1px; padding: 3px; text-align: center; border: 1px solid black"><strong>Result</strong></th></tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Succeeded</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Succeeded</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* —
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code> (no retry)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the first <code>Canceled</code> (the second <code>Canceled</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Pending</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Canceled</code> (the <code>Pending</code> is discarded)
* </td>
* </tr>
* <tr>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Canceled</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* <code>Failed</code>
* </td>
* <td style="border-width: 1px; padding: 3px; border: 1px solid black; text-align: center">
* the <code>Failed</code> (the <code>Canceled</code> is discarded)
* </td>
* </tr>
* </table>
*
* @param delay the amount of time to sleep before retrying
* @param blk the block to execute and potentially retry
*/
def withRetryOnCancel(delay: Span)(blk: => Outcome): Outcome = {
val firstOutcome = blk
firstOutcome match {
case Canceled(ex) =>
if (delay != Span.Zero)
SleepHelper.sleep(delay.millisPart)
SleepHelper.sleep(delay.millisPart)
blk match {
case Succeeded => Succeeded
case failed: Failed => failed // Never hide a failure.
case other => firstOutcome
}
case other => other
}
}
/**
* Indicates whether the test described by the given <code>TestData</code> includes the
* tag <code>org.scalatest.tags.Retryable</code>.
*
* <p>
* This method provides an easy way to selectively retry just tests that are flickering. You can
* annotated such problematic tests with <code>Retryable</code>, and just retry those. Here's
* what it might look like:
* </p>
*
* <pre class="stHighlighted">
* <span class="stReserved">override</span> <span class="stReserved">def</span> withFixture(test: <span class="stType">NoArgTest</span>) = {
* <span class="stReserved">if</span> (isRetryable(test))
* withRetry { <span class="stReserved">super</span>.withFixture(test) }
* <span class="stReserved">else</span>
* <span class="stReserved">super</span>.withFixture(test)
* }
* </pre>
*
*/
def isRetryable(testData: TestData): Boolean = testData.tags.exists(_ == "org.scalatest.tags.Retryable")
}
/**
* Companion object to trait <code>Retries</code> that enables its members to be imported as an
* alternative to mixing them in.
*/
object Retries extends Retries