From 06a34fe417dcf1e1b03f72a175efa0ff27d0eb13 Mon Sep 17 00:00:00 2001
From: Jan Tvrdik <jan.tvrdik@gmail.com>
Date: Mon, 10 Apr 2017 14:48:03 +0200
Subject: [PATCH] FallbackMailer: shuffle mailers with given probability

---
 src/Mail/FallbackMailer.php    | 10 ++++++++--
 tests/Mail/FallbackMailer.phpt | 15 +++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/Mail/FallbackMailer.php b/src/Mail/FallbackMailer.php
index c2a9d00..e770654 100644
--- a/src/Mail/FallbackMailer.php
+++ b/src/Mail/FallbackMailer.php
@@ -31,10 +31,16 @@ class FallbackMailer implements IMailer
 
 	/**
 	 * @param IMailer[]
-	 * @param int $retryWaitTime in miliseconds
+	 * @param int
+	 * @param int   $retryWaitTime      in miliseconds
+	 * @param float $shuffleProbability probability that mailers will be shuffled
 	 */
-	public function __construct(array $mailers, int $retryCount = 3, int $retryWaitTime = 1000)
+	public function __construct(array $mailers, int $retryCount = 3, int $retryWaitTime = 1000, float $shuffleProbability = 0.0)
 	{
+		if ($shuffleProbability > 0.0 && mt_rand() / mt_getrandmax() < $shuffleProbability) {
+			shuffle($mailers);
+		}
+
 		$this->mailers = $mailers;
 		$this->retryCount = $retryCount;
 		$this->retryWaitTime = $retryWaitTime;
diff --git a/tests/Mail/FallbackMailer.phpt b/tests/Mail/FallbackMailer.phpt
index c100dd1..1f265c1 100644
--- a/tests/Mail/FallbackMailer.phpt
+++ b/tests/Mail/FallbackMailer.phpt
@@ -84,3 +84,18 @@ test(function () {
 	$mailer->send(new Message);
 	Assert::null($onFailureCalls);
 });
+
+
+test(function () {
+	$subMailerA = new FailingMailer(0);
+	$subMailerB = new FailingMailer(1);
+
+	mt_srand(5);
+	$mailer = new FallbackMailer([$subMailerA, $subMailerB], 3, 10, 0.5);
+	$mailer->onFailure[] = function (FallbackMailer $sender, SendException $e, IMailer $mailer, Message $mail) use (&$onFailureCalls) {
+		$onFailureCalls[] = $mailer;
+	};
+
+	$mailer->send(new Message);
+	Assert::same([$subMailerB], $onFailureCalls);
+});