Merge pull request #187 from magento-fearless-kiwis/FearlessKiwis-MAGETWO-45566-Credit-Memo-Divide-By-Zero

[FearlessKiwis] MAGETWO-45566 credit memo divide by zero

Author: Tang, Yu(ytang1)

app/code/Magento/Sales/Model/Order/Creditmemo/Total/Discount.php

@@ -25,7 +25,7 @@ public function collect(\Magento\Sales\Model\Order\Creditmemo $creditmemo)
          * Calculate how much shipping discount should be applied
          * basing on how much shipping should be refunded.
          */
-        $baseShippingAmount = $creditmemo->getBaseShippingAmount();
+        $baseShippingAmount = (float)$creditmemo->getBaseShippingAmount();
         if ($baseShippingAmount) {
             $baseShippingDiscount = $baseShippingAmount *
                 $order->getBaseShippingDiscountAmount() /

app/code/Magento/Sales/Test/Unit/Model/Order/Creditmemo/Total/DiscountTest.php

@@ -143,4 +143,71 @@ public function testCollect()
             );
         $this->assertEquals($this->total, $this->total->collect($this->creditmemoMock));
     }
+
+    public function testCollectZeroShipping()
+    {
+        $this->creditmemoMock->expects($this->exactly(2))
+            ->method('setDiscountAmount')
+            ->willReturnSelf();
+        $this->creditmemoMock->expects($this->exactly(2))
+            ->method('setBaseDiscountAmount')
+            ->willReturnSelf();
+        $this->creditmemoMock->expects($this->once())
+            ->method('getOrder')
+            ->willReturn($this->orderMock);
+        $this->creditmemoMock->expects($this->once())
+            ->method('getBaseShippingAmount')
+            ->willReturn('0.0000');
+        $this->orderMock->expects($this->never())
+            ->method('getBaseShippingDiscountAmount');
+        $this->orderMock->expects($this->never())
+            ->method('getBaseShippingAmount');
+        $this->orderMock->expects($this->never())
+            ->method('getShippingAmount');
+        $this->creditmemoMock->expects($this->once())
+            ->method('getAllItems')
+            ->willReturn([$this->creditmemoItemMock]);
+        $this->creditmemoItemMock->expects($this->atLeastOnce())
+            ->method('getOrderItem')
+            ->willReturn($this->orderItemMock);
+        $this->orderItemMock->expects($this->once())
+            ->method('isDummy')
+            ->willReturn(false);
+        $this->orderItemMock->expects($this->once())
+            ->method('getDiscountInvoiced')
+            ->willReturn(1);
+        $this->orderItemMock->expects($this->once())
+            ->method('getBaseDiscountInvoiced')
+            ->willReturn(1);
+        $this->orderItemMock->expects($this->once())
+            ->method('getQtyInvoiced')
+            ->willReturn(1);
+        $this->orderItemMock->expects($this->once())
+            ->method('getDiscountRefunded')
+            ->willReturn(1);
+        $this->orderItemMock->expects($this->once())
+            ->method('getQtyRefunded')
+            ->willReturn(0);
+        $this->creditmemoItemMock->expects($this->once())
+            ->method('isLast')
+            ->willReturn(false);
+        $this->creditmemoItemMock->expects($this->atLeastOnce())
+            ->method('getQty')
+            ->willReturn(1);
+        $this->creditmemoItemMock->expects($this->exactly(1))
+            ->method('setDiscountAmount')
+            ->willReturnSelf();
+        $this->creditmemoItemMock->expects($this->exactly(1))
+            ->method('setBaseDiscountAmount')
+            ->willReturnSelf();
+        $this->creditmemoMock->expects($this->exactly(2))
+            ->method('roundPrice')
+            ->willReturnMap(
+                [
+                    [1, 'regular', true, 1],
+                    [1, 'base', true, 1]
+                ]
+            );
+        $this->assertEquals($this->total, $this->total->collect($this->creditmemoMock));
+    }
 }