MAGETWO-33665 : Refactor Quote module to use mutable data object interfaces

 -- fixes from code review
 -- fixes to testcases

Author: Robert He

app/code/Magento/Quote/Api/Data/PaymentInterface.php

@@ -143,8 +143,8 @@ public function getAdditionalData();
     /**
      * Set payment additional details
      *
-     * @param string[] $additionalData
+     * @param string $additionalData
      * @return $this
      */
-    public function setAdditionalData(array $additionalData = null);
+    public function setAdditionalData($additionalData);
 }

app/code/Magento/Quote/Model/Cart/ShippingMethod.php

@@ -28,6 +28,7 @@ public function getCarrierCode()
     /**
      * Sets the shipping carrier code.
      *
+     * @param string $carrierCode
      * @return $this
      */
     public function setCarrierCode($carrierCode)
@@ -48,6 +49,7 @@ public function getMethodCode()
     /**
      * Sets the shipping method code.
      *
+     * @param string $methodCode
      * @return $this
      */
     public function setMethodCode($methodCode)
@@ -68,6 +70,7 @@ public function getCarrierTitle()
     /**
      * Sets the shipping carrier title.
      *
+     * @param string $carrierTitle
      * @return $this
      */
     public function setCarrierTitle($carrierTitle)
@@ -88,6 +91,7 @@ public function getMethodTitle()
     /**
      * Sets the shipping method title.
      *
+     * @param string $methodTitle
      * @return $this
      */
     public function setMethodTitle($methodTitle)
@@ -108,6 +112,7 @@ public function getAmount()
     /**
      * Sets the shipping amount in store currency.
      *
+     * @param float $amount
      * @return $this
      */
     public function setAmount($amount)
@@ -128,6 +133,7 @@ public function getBaseAmount()
     /**
      * Sets the shipping amount in base currency.
      *
+     * @param float $baseAmount
      * @return $this
      */
     public function setBaseAmount($baseAmount)
@@ -149,6 +155,7 @@ public function getAvailable()
     /**
      * Sets the value of the availability flag for the current shipping method.
      *
+     * @param bool $available
      * @return $this
      */
     public function setAvailable($available)

app/code/Magento/Quote/Model/Quote/Payment.php

@@ -404,10 +404,10 @@ public function getAdditionalData()
     /**
      * Set payment additional details
      *
-     * @param string[] $additionalData
+     * @param string $additionalData
      * @return $this
      */
-    public function setAdditionalData(array $additionalData = null)
+    public function setAdditionalData($additionalData)
     {
         return $this->setData(self::KEY_ADDITIONAL_DATA, $additionalData);
     }

dev/tests/api-functional/testsuite/Magento/Sales/Service/V1/OrderCreateTest.php

@@ -57,7 +57,7 @@ protected function prepareOrder()
         $orderItem->setSku('sku#1');
         if (TESTS_WEB_API_ADAPTER == self::ADAPTER_SOAP) {
             $orderItem->setData('parent_item', $orderItem->getData() + ['parent_item' => null]);
-            $orderItem->setAdditionalData(['test']);
+            $orderItem->setAdditionalData('test');
         } else {
             $orderItem->setData('parent_item', ['weight' => 1]);
         }

dev/tests/integration/testsuite/Magento/Checkout/_files/quote_with_payment_saved.php

@@ -22,6 +22,6 @@
     ->setCcType('visa')
     ->setCcExpYear(2014)
     ->setCcExpMonth(1)
-    ->setAdditionalData($paymentDetails);
+    ->setAdditionalData(serialize($paymentDetails));
 
 $quote->collectTotals()->save();