Merge pull request #16 from sabbelasichon/add-event-middleware

FEATURE: Add EventMiddleware

Classes/Middleware/Event/CommandEventInterface.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the "t3_tactician" Extension for TYPO3 CMS.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ */
+
+namespace Ssch\T3Tactician\Middleware\Event;
+
+interface CommandEventInterface
+{
+    public function getCommand(): object;
+
+    public function getName(): string;
+}

Classes/Middleware/Event/CommandFailed.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the "t3_tactician" Extension for TYPO3 CMS.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ */
+
+namespace Ssch\T3Tactician\Middleware\Event;
+
+final class CommandFailed implements CommandEventInterface
+{
+    private object $command;
+
+    private \Exception $exception;
+
+    private bool $exceptionCaught = false;
+
+    public function __construct(object $command, \Exception $exception)
+    {
+        $this->command = $command;
+        $this->exception = $exception;
+    }
+
+    public function getException(): \Exception
+    {
+        return $this->exception;
+    }
+
+    public function catchException(): void
+    {
+        $this->exceptionCaught = true;
+    }
+
+    public function getCommand(): object
+    {
+        return $this->command;
+    }
+
+    public function getName(): string
+    {
+        return 'command.failed';
+    }
+
+    public function isExceptionCaught(): bool
+    {
+        return $this->exceptionCaught;
+    }
+}

Classes/Middleware/Event/CommandHandled.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the "t3_tactician" Extension for TYPO3 CMS.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ */
+
+namespace Ssch\T3Tactician\Middleware\Event;
+
+final class CommandHandled implements CommandEventInterface
+{
+    private object $command;
+
+    public function __construct(object $command)
+    {
+        $this->command = $command;
+    }
+
+    public function getCommand(): object
+    {
+        return $this->command;
+    }
+
+    public function getName(): string
+    {
+        return 'command.received';
+    }
+}

Classes/Middleware/Event/CommandReceived.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the "t3_tactician" Extension for TYPO3 CMS.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ */
+
+namespace Ssch\T3Tactician\Middleware\Event;
+
+final class CommandReceived implements CommandEventInterface
+{
+    private object $command;
+
+    public function __construct(object $command)
+    {
+        $this->command = $command;
+    }
+
+    public function getCommand(): object
+    {
+        return $this->command;
+    }
+
+    public function getName(): string
+    {
+        return 'command.handled';
+    }
+}

Classes/Middleware/EventMiddleware.php

@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the "t3_tactician" Extension for TYPO3 CMS.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ */
+
+namespace Ssch\T3Tactician\Middleware;
+
+use League\Tactician\Middleware;
+use Psr\EventDispatcher\EventDispatcherInterface;
+use Ssch\T3Tactician\Middleware\Event\CommandFailed;
+use Ssch\T3Tactician\Middleware\Event\CommandHandled;
+use Ssch\T3Tactician\Middleware\Event\CommandReceived;
+
+final class EventMiddleware implements Middleware
+{
+    private EventDispatcherInterface $eventDispatcher;
+
+    public function __construct(EventDispatcherInterface $eventDispatcher)
+    {
+        $this->eventDispatcher = $eventDispatcher;
+    }
+
+    public function execute($command, callable $next)
+    {
+        try {
+            $this->eventDispatcher->dispatch(new CommandReceived($command));
+
+            $returnValue = $next($command);
+
+            $this->eventDispatcher->dispatch(new CommandHandled($command));
+
+            return $returnValue;
+        } catch (\Exception $e) {
+            $event = new CommandFailed($command, $e);
+            $this->eventDispatcher->dispatch($event);
+
+            if (! $event->isExceptionCaught()) {
+                throw $e;
+            }
+
+            return null;
+        }
+    }
+}

Tests/Functional/Fixtures/Extensions/t3_tactician_test/Configuration/CommandBus.php

@@ -12,6 +12,7 @@
 use League\Tactician\Handler\CommandHandlerMiddleware;
 use League\Tactician\Handler\MethodNameInflector\ClassNameInflector;
 use League\Tactician\Handler\MethodNameInflector\InvokeInflector;
+use Ssch\T3Tactician\Middleware\EventMiddleware;
 use Ssch\T3Tactician\Middleware\ValidatorMiddleware;
 
 return [
@@ -22,7 +23,11 @@
         ],
         'foo' => [
             'method_inflector' => ClassNameInflector::class,
-            'middleware' => [ValidatorMiddleware::class, 'tactician.commandbus.foo.middleware.command_handler'],
+            'middleware' => [
+                EventMiddleware::class,
+                ValidatorMiddleware::class,
+                'tactician.commandbus.foo.middleware.command_handler',
+            ],
         ],
         'bar' => [
             'middleware' => [ValidatorMiddleware::class, CommandHandlerMiddleware::class],

Tests/Unit/Middleware/EventMiddlewareTest.php

@@ -0,0 +1,97 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the "t3_tactician" Extension for TYPO3 CMS.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ */
+
+namespace Ssch\T3Tactician\Tests\Unit\Middleware;
+
+use PHPUnit\Framework\TestCase;
+use Prophecy\PhpUnit\ProphecyTrait;
+use Psr\EventDispatcher\EventDispatcherInterface;
+use Ssch\T3Tactician\Middleware\Event\CommandFailed;
+use Ssch\T3Tactician\Middleware\EventMiddleware;
+use Ssch\T3Tactician\Tests\Unit\Fixtures\FakeCommand;
+
+final class EventMiddlewareTest extends TestCase
+{
+    use ProphecyTrait;
+
+    public function testThatEventsAreCalledSuccessfully(): void
+    {
+        // Arrange
+        $eventDispatcher = new class() implements EventDispatcherInterface {
+            public array $firedEvents = [];
+
+            public function dispatch(object $event): object
+            {
+                $this->firedEvents[] = $event;
+
+                return $event;
+            }
+        };
+
+        $subject = new EventMiddleware($eventDispatcher);
+
+        // Act
+        $subject->execute(new FakeCommand(), function () {
+        });
+
+        // Assert
+        self::assertCount(2, $eventDispatcher->firedEvents);
+    }
+
+    public function testThatFailingCommandFiresEventButThrowsExceptionInTheEnd(): void
+    {
+        // Assert
+        $this->expectException(\Exception::class);
+
+        // Arrange
+        $eventDispatcher = new class() implements EventDispatcherInterface {
+            public function dispatch(object $event): object
+            {
+                return $event;
+            }
+        };
+
+        $subject = new EventMiddleware($eventDispatcher);
+
+        // Act
+        $subject->execute(new FakeCommand(), function () {
+            throw new \Exception('Some deep failure is thrown in your application');
+        });
+    }
+
+    public function testThatFailingCommandFiresEventAndCatchesException(): void
+    {
+        $eventDispatcher = new class() implements EventDispatcherInterface {
+            public array $firedEvents = [];
+
+            public function dispatch(object $event): object
+            {
+                if ($event instanceof CommandFailed) {
+                    $event->catchException();
+                }
+
+                $this->firedEvents[] = $event;
+
+                return $event;
+            }
+        };
+
+        $subject = new EventMiddleware($eventDispatcher);
+
+        // Act
+        $subject->execute(new FakeCommand(), function () {
+            throw new \Exception('Some deep failure is thrown in your application');
+        });
+
+        // Assert
+        self::assertCount(2, $eventDispatcher->firedEvents);
+    }
+}