Show converted value for validateForRefund error message

Author: Rafael Kassner

app/code/Magento/Sales/Model/Service/CreditmemoService.php

@@ -196,13 +196,13 @@ protected function validateForRefund(\Magento\Sales\Api\Data\CreditmemoInterface
             $creditmemo->getOrder()->getBaseTotalRefunded() + $creditmemo->getBaseGrandTotal()
         );
         if ($baseOrderRefund > $this->priceCurrency->round($creditmemo->getOrder()->getBaseTotalPaid())) {
-            $baseAvailableRefund = $creditmemo->getOrder()->getBaseTotalPaid()
-                - $creditmemo->getOrder()->getBaseTotalRefunded();
+            $availableRefund = $creditmemo->getOrder()->getTotalPaid()
+                - $creditmemo->getOrder()->getTotalRefunded();
 
             throw new \Magento\Framework\Exception\LocalizedException(
                 __(
                     'The most money available to refund is %1.',
-                    $creditmemo->getOrder()->formatPriceTxt($baseAvailableRefund)
+                    $creditmemo->getOrder()->formatPriceTxt($availableRefund)
                 )
             );
         }

app/code/Magento/Sales/Test/Unit/Model/Service/CreditmemoServiceTest.php

@@ -343,20 +343,74 @@ public function testRefundExpectsMoneyAvailableToReturn()
             ->willReturn($order);
         $creditMemo->method('getBaseGrandTotal')
             ->willReturn($baseGrandTotal);
+        $creditMemo->method('getGrandTotal')
+            ->willReturn($baseGrandTotal);
         $order->method('getBaseTotalRefunded')
             ->willReturn($baseTotalRefunded);
+        $order->method('getTotalRefunded')
+            ->willReturn($baseTotalRefunded);
         $this->priceCurrency->method('round')
             ->withConsecutive([$baseTotalRefunded + $baseGrandTotal], [$baseTotalPaid])
             ->willReturnOnConsecutiveCalls($baseTotalRefunded + $baseGrandTotal, $baseTotalPaid);
         $order->method('getBaseTotalPaid')
             ->willReturn($baseTotalPaid);
+        $order->method('getTotalPaid')
+            ->willReturn($baseTotalPaid);
         $baseAvailableRefund = $baseTotalPaid - $baseTotalRefunded;
         $order->method('formatPriceTxt')
             ->with($baseAvailableRefund)
             ->willReturn($baseAvailableRefund);
         $this->creditmemoService->refund($creditMemo, true);
     }
 
+    /**
+     * @expectedExceptionMessage The most money available to refund is €0.88.
+     * @expectedException \Magento\Framework\Exception\LocalizedException
+     */
+    public function testMultiCurrencyRefundExpectsMoneyAvailableToReturn()
+    {
+        $baseGrandTotal = 10.00;
+        $baseTotalRefunded = 9.00;
+        $baseTotalPaid = 10;
+
+        $grandTotal = 8.81;
+        $totalRefunded = 7.929;
+        $totalPaid = 8.81;
+
+        /** @var CreditmemoInterface|MockObject $creditMemo */
+        $creditMemo = $this->getMockBuilder(CreditmemoInterface::class)
+            ->setMethods(['getId', 'getOrder'])
+            ->getMockForAbstractClass();
+        $creditMemo->method('getId')
+            ->willReturn(null);
+        /** @var Order|MockObject $order */
+        $order = $this->getMockBuilder(Order::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $creditMemo->method('getOrder')
+            ->willReturn($order);
+        $creditMemo->method('getBaseGrandTotal')
+            ->willReturn($baseGrandTotal);
+        $creditMemo->method('getGrandTotal')
+            ->willReturn($grandTotal);
+        $order->method('getBaseTotalRefunded')
+            ->willReturn($baseTotalRefunded);
+        $order->method('getTotalRefunded')
+            ->willReturn($totalRefunded);
+        $this->priceCurrency->method('round')
+            ->withConsecutive([$baseTotalRefunded + $baseGrandTotal], [$baseTotalPaid])
+            ->willReturnOnConsecutiveCalls($baseTotalRefunded + $baseGrandTotal, $baseTotalPaid);
+        $order->method('getBaseTotalPaid')
+            ->willReturn($baseTotalPaid);
+        $order->method('getTotalPaid')
+            ->willReturn($totalPaid);
+        $availableRefund = $totalPaid - $totalRefunded;
+        $order->method('formatPriceTxt')
+            ->with($availableRefund)
+            ->willReturn(sprintf('€%.2f', $availableRefund));
+        $this->creditmemoService->refund($creditMemo, true);
+    }
+
     /**
      * @expectedExceptionMessage We cannot register an existing credit memo.
      * @expectedException \Magento\Framework\Exception\LocalizedException