Format refund amount in the base currency

Author: kassner

app/code/Magento/Sales/Model/Order.php

@@ -1784,6 +1784,17 @@ public function formatBasePricePrecision($price, $precision)
         return $this->getBaseCurrency()->formatPrecision($price, $precision);
     }
 
+    /**
+     * Retrieve text formatted base price value
+     *
+     * @param float $price
+     * @return string
+     */
+    public function formatBasePriceTxt($price)
+    {
+        return $this->getBaseCurrency()->formatTxt($price);
+    }
+
     /**
      * Is currency different
      *

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

@@ -202,7 +202,7 @@ protected function validateForRefund(\Magento\Sales\Api\Data\CreditmemoInterface
             throw new \Magento\Framework\Exception\LocalizedException(
                 __(
                     'The most money available to refund is %1.',
-                    $creditmemo->getOrder()->formatPriceTxt($baseAvailableRefund)
+                    $creditmemo->getOrder()->formatBasePriceTxt($baseAvailableRefund)
                 )
             );
         }

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

@@ -351,7 +351,7 @@ public function testRefundExpectsMoneyAvailableToReturn()
         $order->method('getBaseTotalPaid')
             ->willReturn($baseTotalPaid);
         $baseAvailableRefund = $baseTotalPaid - $baseTotalRefunded;
-        $order->method('formatPriceTxt')
+        $order->method('formatBasePriceTxt')
             ->with($baseAvailableRefund)
             ->willReturn($baseAvailableRefund);
         $this->creditmemoService->refund($creditMemo, true);
@@ -369,4 +369,51 @@ public function testRefundDoNotExpectsId()
         $creditMemoMock->expects($this->once())->method('getId')->willReturn(444);
         $this->creditmemoService->refund($creditMemoMock, true);
     }
+
+    /**
+     * @expectedExceptionMessage The most money available to refund is $1.00.
+     * @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);
+        $baseAvailableRefund = $baseTotalPaid - $baseTotalRefunded;
+        $order->method('formatBasePriceTxt')
+            ->with($baseAvailableRefund)
+            ->willReturn(sprintf('$%.2f', $baseAvailableRefund));
+        $this->creditmemoService->refund($creditMemo, true);
+    }
 }