MAGETWO-72775: is_subscribed extended attribute isn't returned in REST customer calls

Author: StasKozar

app/code/Magento/Newsletter/Model/Plugin/CustomerPlugin.php

@@ -83,9 +83,9 @@ public function afterSave(CustomerRepository $subject, CustomerInterface $result
         if ($newExtensionAttributes
             && $initialExtensionAttributes->getIsSubscribed() !== $newExtensionAttributes->getIsSubscribed()
         ) {
-            if ($newExtensionAttributes->getIsSubscribed() === true) {
+            if ($newExtensionAttributes->getIsSubscribed()) {
                 $subscriber->subscribeCustomerById($resultId);
-            } elseif ($newExtensionAttributes->getIsSubscribed() === false) {
+            } else {
                 $subscriber->unsubscribeCustomerById($resultId);
             }
         }

app/code/Magento/Newsletter/Test/Unit/Model/Plugin/CustomerPluginTest.php

@@ -68,7 +68,7 @@ protected function setUp()
                     'updateSubscription',
                     'subscribeCustomerById',
                     'unsubscribeCustomerById',
-                    'isSubscribed'
+                    'isSubscribed',
                 ]
             )->disableOriginalConstructor()
             ->getMock();
@@ -77,14 +77,14 @@ protected function setUp()
             ->setMethods(['create'])
             ->getMock();
         $this->customerExtensionMock = $this->getMockBuilder(CustomerExtensionInterface::class)
-            ->setMethods(["getIsSubscribed", "setIsSubscribed"])
+            ->setMethods(['getIsSubscribed', 'setIsSubscribed'])
             ->disableOriginalConstructor()
             ->getMockForAbstractClass();
         $this->subscriberResourceMock = $this->getMockBuilder(Subscriber::class)
             ->disableOriginalConstructor()
             ->getMock();
         $this->customerMock = $this->getMockBuilder(CustomerInterface::class)
-            ->setMethods(["getExtensionAttributes"])
+            ->setMethods(['getExtensionAttributes'])
             ->disableOriginalConstructor()
             ->getMockForAbstractClass();
         $this->subscriberFactory->expects($this->any())->method('create')->willReturn($this->subscriber);
@@ -104,6 +104,7 @@ protected function setUp()
      * @param bool $subscriptionOriginalValue
      * @param bool $subscriptionNewValue
      * @dataProvider afterSaveDataProvider
+     * @return void
      */
     public function testAfterSave($subscriptionOriginalValue, $subscriptionNewValue)
     {
@@ -137,9 +138,9 @@ public function testAfterSave($subscriptionOriginalValue, $subscriptionNewValue)
             ->willReturn($subscriptionNewValue);
 
         if ($subscriptionOriginalValue !== $subscriptionNewValue) {
-            if ($subscriptionNewValue === true) {
+            if ($subscriptionNewValue) {
                 $this->subscriber->expects($this->once())->method('subscribeCustomerById')->with($customerId);
-            } elseif ($subscriptionNewValue === false) {
+            } else {
                 $this->subscriber->expects($this->once())->method('unsubscribeCustomerById')->with($customerId);
             }
             $this->subscriber->expects($this->once())->method('isSubscribed')->willReturn($subscriptionNewValue);
@@ -196,6 +197,7 @@ public function testAroundDeleteById()
      * @param int|null $subscriberStatusValue
      * @param bool $isSubscribed
      * @dataProvider afterGetByIdDataProvider
+     * @return void
      */
     public function testAfterGetByIdCreatesExtensionAttributesIfItIsNotSet(
         $subscriberStatusKey,