Update Transaction model and docs

README.md

@@ -124,6 +124,18 @@ $subscriber->addListener(MessageFailedEvent::class, function (MessageFailedEvent
 
 ### Transaction
 
+Transaction Middleware accepts three function arguments, each for every stage of the transaction: begin, commit, and rollback. 
+Going with this approach allows you to use any ORM you prefer or even using the native \PDO object to interact with your persistence layer.
+```php
+$pdo = new \PDO('{connection_dsn}')
+
+$transaction = new \SasaB\MessageBus\Middleware\TransactionMiddleware(
+    fn(): void => $pdo->beginTransaction();,
+    fn(): void => $pdo->commit();,
+    fn(\Throwable $error): void => $pdo->rollBack();,
+);
+```
+
 ### Response Types
 
 Library wraps the Handler return values into __Response value objects__ to provide a consistent API and so that you can
@@ -139,6 +151,8 @@ All Response value objects extend the `SasaB\MessageBus\Response` abstract class
 2. `SasaB\MessageBus\Response\Delegated` which wraps objects and delegates calls to properties and methods to the underlying object
 3. `SasaB\MessageBus\Response\Collection` and `SasaB\MessageBus\Response\Map` which wrap number indexed arrays (lists) and string indexed arrays (maps) and implement `\Countable`, `\ArrayAccess` and `\IteratorAggregate` interfaces
 
+You can also add your own custom Response value objects by extending the abstract class `SasaB\MessageBus\Response` and returning them in the appropriate handler.
+
 ## Getting Started
 
 ### Stand-alone usage

src/Middleware/TransactionMiddleware.php

@@ -29,7 +29,7 @@ public function __invoke(Message $message, \Closure $next): mixed
         try {
             $result = $next($message);
         } catch (\Exception $e) {
-            $this->rollback->call($this);
+            $this->rollback->call($this, $e);
             throw MiddlewareException::handler(handler: __CLASS__, error: $e);
         }
         $this->commit->call($this);

tests/Unit/MiddlewareTest.php

@@ -112,7 +112,7 @@ function () {
     public function test_it_rollbacks_transaction_on_error(): void
     {
         $this->expectOutputString(
-            "Begin|Rollback"
+            "Begin|Rollback Command Fails"
         );
 
         $transactionMiddleware = new TransactionMiddleware(
@@ -122,8 +122,8 @@ function () {
             function () {
                 echo "|Commit";
             },
-            function () {
-                echo "Rollback";
+            function (\Throwable $throwable) {
+                echo "Rollback ".$throwable->getMessage();
             },
         );