qa: Move EventDispatcherFactory to correct location and test

This patch moves the `EventDispatcherFactory` to the root source
directory from within the `ListenerProvider` directory, and adds tests
for its behaviors.

Author: weierophinney

src/ListenerProvider/EventDispatcherFactory.php renamed to src/EventDispatcherFactory.php

@@ -0,0 +1,52 @@
+<?php
+/**
+ * @see       https://github.com/phly/phly-event-dispatcher for the canonical source repository
+ * @copyright Copyright (c) 2018 Matthew Weier O'Phinney (https:/mwop.net)
+ * @license   https://github.com/phly/phly-event-dispatcher/blob/master/LICENSE.md New BSD License
+ */
+
+declare(strict_types=1);
+
+namespace Phly\EventDispatcher;
+
+use Phly\EventDispatcher\ErrorEmittingDispatcher;
+use Phly\EventDispatcher\EventDispatcher;
+use Phly\EventDispatcher\EventDispatcherFactory;
+use PHPUnit\Framework\TestCase;
+use Psr\Container\ContainerInterface;
+use Psr\EventDispatcher\ListenerProviderInterface;
+use stdClass;
+use TypeError;
+
+class EventDispatcherFactoryTest extends TestCase
+{
+    public function setUp()
+    {
+        $this->provider  = $this->prophesize(ListenerProviderInterface::class)->reveal();
+        $this->container = $this->prophesize(ContainerInterface::class);
+        $this->container->get(ListenerProviderInterface::class)->willReturn($this->provider);
+        $this->factory = new EventDispatcherFactory();
+    }
+
+    public function testFactoryRaisesTypeErrorIfReturnedServiceIsNotAnEventDispatcher()
+    {
+        $this->expectException(TypeError::class);
+        ($this->factory)($this->container->reveal(), stdClass::class);
+    }
+
+    public function knownDispatcherTypes() : iterable
+    {
+        yield EventDispatcher::class => [EventDispatcher::class];
+        yield ErrorEmittingDispatcher::class => [ErrorEmittingDispatcher::class];
+    }
+
+    /**
+     * @dataProvider knownDispatcherTypes
+     */
+    public function testFactoryCanCreateEventDispatcher(string $type)
+    {
+        $dispatcher = ($this->factory)($this->container->reveal(), $type);
+        $this->assertInstanceOf($type, $dispatcher);
+        $this->assertAttributeSame($this->provider, 'listenerProvider', $dispatcher);
+    }
+}