MC-20193: Invoice Sales Email not send

Author: StasKozar

app/code/Magento/Quote/Observer/SubmitObserver.php

@@ -10,6 +10,9 @@
 use Magento\Framework\Event\ObserverInterface;
 use Magento\Sales\Model\Order\Invoice;
 
+/**
+ * Class responsive for sending order and invoice emails when it's created through storefront.
+ */
 class SubmitObserver implements ObserverInterface
 {
     /**
@@ -30,6 +33,7 @@ class SubmitObserver implements ObserverInterface
     /**
      * @param \Psr\Log\LoggerInterface $logger
      * @param OrderSender $orderSender
+     * @param InvoiceSender $invoiceSender
      */
     public function __construct(
         \Psr\Log\LoggerInterface $logger,
@@ -42,6 +46,8 @@ public function __construct(
     }
 
     /**
+     * Send order and invoice email.
+     *
      * @param \Magento\Framework\Event\Observer $observer
      *
      * @return void

app/code/Magento/Quote/Test/Unit/Observer/SubmitObserverTest.php

@@ -10,6 +10,10 @@
 use Magento\Sales\Model\Order\Invoice;
 use Magento\Sales\Model\ResourceModel\Order\Invoice\Collection as InvoiceCollection;
 
+/**
+ * Test for \Magento\Quote\Observer\SubmitObserver class.
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
 class SubmitObserverTest extends \PHPUnit\Framework\TestCase
 {
     /**