Add tests for ChainHandler class

Author: yceruto

Tests/Handler/ChainHandlerTest.php

@@ -0,0 +1,52 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Messenger\Tests\Handler;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Messenger\Handler\ChainHandler;
+use Symfony\Component\Messenger\Tests\Fixtures\DummyMessage;
+
+class ChainHandlerTest extends TestCase
+{
+    public function testItCallsTheHandlersAndReturnsAllResults()
+    {
+        $message = new DummyMessage('Hey');
+
+        $handler1 = $this->createPartialMock(\stdClass::class, array('__invoke'));
+        $handler1
+            ->expects($this->once())
+            ->method('__invoke')
+            ->with($message)
+            ->willReturn('Hello')
+        ;
+        $handler2 = $this->createPartialMock(\stdClass::class, array('__invoke'));
+        $handler2
+            ->expects($this->once())
+            ->method('__invoke')
+            ->with($message)
+            ->willReturn('World')
+        ;
+
+        $results = (new ChainHandler(array($handler1, $handler2)))($message);
+
+        $this->assertSame(array('Hello', 'World'), $results);
+    }
+
+    /**
+     * @expectedException \InvalidArgumentException
+     * @expectedExceptionMessage A collection of message handlers requires at least one handler.
+     */
+    public function testInvalidArgumentExceptionOnEmptyHandlers()
+    {
+        new ChainHandler(array());
+    }
+}