upd: Improve error handling, combine similar response classes into one

src/Message/AuthorizeRequest.php

@@ -159,8 +159,8 @@ public function getData(): array
         ];
     }
 
-    protected function createResponse($data, int $statusCode): AuthorizeResponse
+    protected function createResponse($data, int $statusCode): TransactionResponse
     {
-        return $this->response = new AuthorizeResponse($this, $data, $statusCode);
+        return $this->response = new TransactionResponse($this, $data, $statusCode);
     }
 }

src/Message/PurchaseRequest.php

@@ -160,8 +160,8 @@ public function getData(): array
         ];
     }
 
-    protected function createResponse($data, int $statusCode): PurchaseResponse
+    protected function createResponse($data, int $statusCode): TransactionResponse
     {
-        return $this->response = new PurchaseResponse($this, $data, $statusCode);
+        return $this->response = new TransactionResponse($this, $data, $statusCode);
     }
 }

src/Message/AuthorizeResponse.php → src/Message/TransactionResponse.php

@@ -2,7 +2,7 @@
 
 namespace Ampeco\OmnipayMonri\Message;
 
-class AuthorizeResponse extends AbstractResponse
+class TransactionResponse extends AbstractResponse
 {
     public function isSuccessful(): bool
     {
@@ -16,6 +16,10 @@ public function getTransactionReference()
 
     public function getMessage(): ?string
     {
-        return isset($this->data['errors']) ? current($this->data['errors']) : null;
+        if (isset($this->data['errors'])) {
+            return current($this->data['errors']);
+        }
+
+        return $this->data['transaction']['response_message'] ?? null;
     }
-}
+}