qa: adds tests for InvalidListenerException

Creates InvalidListenerExceptionTest.

Author: weierophinney

test/Exception/InvalidListenerExceptionTest.php

@@ -0,0 +1,28 @@
+<?php
+/**
+ * @see       https://github.com/phly/phly-event-dispatcher for the canonical source repository
+ * @copyright Copyright (c) 2019 Matthew Weier O'Phinney (https:/mwop.net)
+ * @license   https://github.com/phly/phly-event-dispatcher/blob/master/LICENSE.md New BSD License
+ */
+
+namespace PhlyTest\EventDispatcher\Exception;
+
+use Phly\EventDispatcher\Exception\InvalidListenerException;
+use PHPUnit\Framework\TestCase;
+
+class InvalidListenerExceptionTest extends TestCase
+{
+    public function testForNonCallableService()
+    {
+        $instance = InvalidListenerException::forNonCallableService($this);
+        $this->assertInstanceOf(InvalidListenerException::class, $instance);
+        $this->assertContains('type "object" is invalid; must be a PHP callable', $instance->getMessage());
+    }
+
+    public function testForNonCallableInstance()
+    {
+        $instance = InvalidListenerException::forNonCallableInstance($this);
+        $this->assertInstanceOf(InvalidListenerException::class, $instance);
+        $this->assertContains('type "' . __CLASS__ . '" is invalid; must be a callable', $instance->getMessage());
+    }
+}