diff --git a/app/code/Magento/Weee/Test/Unit/App/Action/ContextPluginTest.php b/app/code/Magento/Weee/Test/Unit/App/Action/ContextPluginTest.php
index b28a223ef2dce..6bf9258f98fbe 100644
--- a/app/code/Magento/Weee/Test/Unit/App/Action/ContextPluginTest.php
+++ b/app/code/Magento/Weee/Test/Unit/App/Action/ContextPluginTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -92,7 +92,7 @@ class ContextPluginTest extends TestCase
      */
     protected $contextPlugin;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->objectManager = new ObjectManager($this);
 
diff --git a/app/code/Magento/Weee/Test/Unit/Block/Element/Weee/TaxTest.php b/app/code/Magento/Weee/Test/Unit/Block/Element/Weee/TaxTest.php
index 7145e56783c32..2b6e582174382 100644
--- a/app/code/Magento/Weee/Test/Unit/Block/Element/Weee/TaxTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Block/Element/Weee/TaxTest.php
@@ -1,33 +1,44 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Block\Element\Weee;
 
-class TaxTest extends \PHPUnit\Framework\TestCase
+use Magento\Catalog\Block\Adminhtml\Product\Helper\Form\Weight;
+use Magento\Framework\Data\Form\Element\CollectionFactory;
+use Magento\Framework\Data\Form\Element\Factory;
+use Magento\Framework\DataObject;
+use Magento\Framework\Locale\Currency;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Store\Model\Store;
+use Magento\Store\Model\StoreManager;
+use Magento\Weee\Block\Element\Weee\Tax;
+use PHPUnit\Framework\TestCase;
+
+class TaxTest extends TestCase
 {
     /**
-     * @var \Magento\Catalog\Block\Adminhtml\Product\Helper\Form\Weight
+     * @var Weight
      */
     protected $model;
 
     public function testGetEscapedValue()
     {
-        $objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+        $objectManager = new ObjectManager($this);
 
         $inputValue = [
             ['value' => '30000.4'],
         ];
 
         $collectionFactory = $this->createPartialMock(
-            \Magento\Framework\Data\Form\Element\CollectionFactory::class,
+            CollectionFactory::class,
             ['create']
         );
 
-        $storeManager = $this->createMock(\Magento\Store\Model\StoreManager::class);
+        $storeManager = $this->createMock(StoreManager::class);
 
-        $localeCurrency = $this->createMock(\Magento\Framework\Locale\Currency::class);
+        $localeCurrency = $this->createMock(Currency::class);
 
         $currency = $this->createMock(\Magento\Framework\Currency::class);
 
@@ -43,7 +54,7 @@ public function testGetEscapedValue()
             'getCurrency'
         )->willReturn($currency);
 
-        $store = $this->createMock(\Magento\Store\Model\Store::class);
+        $store = $this->createMock(Store::class);
 
         $storeManager->expects(
             $this->any()
@@ -51,10 +62,10 @@ public function testGetEscapedValue()
             'getStore'
         )->willReturn($store);
 
-        $factory = $this->createMock(\Magento\Framework\Data\Form\Element\Factory::class);
+        $factory = $this->createMock(Factory::class);
 
         $this->model = $objectManager->getObject(
-            \Magento\Weee\Block\Element\Weee\Tax::class,
+            Tax::class,
             [
                 'factoryElement' => $factory,
                 'factoryCollection' => $collectionFactory,
@@ -64,7 +75,7 @@ public function testGetEscapedValue()
         );
 
         $this->model->setValue($inputValue);
-        $this->model->setEntityAttribute(new \Magento\Framework\DataObject(['store_id' => 1]));
+        $this->model->setEntityAttribute(new DataObject(['store_id' => 1]));
 
         $return = $this->model->getEscapedValue();
         $this->assertEquals(
diff --git a/app/code/Magento/Weee/Test/Unit/Block/Item/Price/RendererTest.php b/app/code/Magento/Weee/Test/Unit/Block/Item/Price/RendererTest.php
index 8b770ea763cdd..2cf5e5cfb7107 100644
--- a/app/code/Magento/Weee/Test/Unit/Block/Item/Price/RendererTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Block/Item/Price/RendererTest.php
@@ -1,42 +1,49 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Block\Item\Price;
 
+use Magento\Directory\Model\PriceCurrency;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Quote\Model\Quote\Item;
+use Magento\Weee\Block\Item\Price\Renderer;
+use Magento\Weee\Helper\Data;
 use Magento\Weee\Model\Tax as WeeeDisplayConfig;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
 
-class RendererTest extends \PHPUnit\Framework\TestCase
+class RendererTest extends TestCase
 {
     /**
-     * @var \Magento\Weee\Block\Item\Price\Renderer
+     * @var Renderer
      */
     protected $renderer;
 
     /**
-     * @var \Magento\Weee\Helper\Data|\PHPUnit_Framework_MockObject_MockObject
+     * @var Data|MockObject
      */
     protected $weeeHelper;
 
     /**
-     * @var \Magento\Directory\Model\PriceCurrency|\PHPUnit_Framework_MockObject_MockObject
+     * @var PriceCurrency|MockObject
      */
     protected $priceCurrency;
 
     /**
-     * @var \Magento\Quote\Model\Quote\Item|\PHPUnit_Framework_MockObject_MockObject
+     * @var Item|MockObject
      */
     protected $item;
 
     const STORE_ID = 'store_id';
     const ZONE = 'zone';
 
-    protected function setUp()
+    protected function setUp(): void
     {
-        $objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+        $objectManager = new ObjectManager($this);
 
-        $this->weeeHelper = $this->getMockBuilder(\Magento\Weee\Helper\Data::class)
+        $this->weeeHelper = $this->getMockBuilder(Data::class)
             ->disableOriginalConstructor()
             ->setMethods([
                 'isEnabled',
@@ -48,12 +55,12 @@ protected function setUp()
             ])
             ->getMock();
 
-        $this->priceCurrency = $this->getMockBuilder(\Magento\Directory\Model\PriceCurrency::class)
+        $this->priceCurrency = $this->getMockBuilder(PriceCurrency::class)
             ->disableOriginalConstructor()
             ->setMethods(['format'])
             ->getMock();
 
-        $this->item = $this->getMockBuilder(\Magento\Quote\Model\Quote\Item::class)
+        $this->item = $this->getMockBuilder(Item::class)
             ->disableOriginalConstructor()
             ->setMethods([
                 '__wakeup',
@@ -80,7 +87,7 @@ protected function setUp()
             ->will($this->returnValue(self::STORE_ID));
 
         $this->renderer = $objectManager->getObject(
-            \Magento\Weee\Block\Item\Price\Renderer::class,
+            Renderer::class,
             [
                 'weeeHelper' => $this->weeeHelper,
                 'priceCurrency' => $this->priceCurrency,
diff --git a/app/code/Magento/Weee/Test/Unit/Helper/DataTest.php b/app/code/Magento/Weee/Test/Unit/Helper/DataTest.php
index 7d0f6723976be..30b5844786fa7 100644
--- a/app/code/Magento/Weee/Test/Unit/Helper/DataTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Helper/DataTest.php
@@ -1,17 +1,30 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Helper;
 
+use Magento\Bundle\Model\Product\Type;
+use Magento\Catalog\Model\Product;
+use Magento\Catalog\Model\Product\Type\Simple;
+use Magento\Framework\DataObject;
+use Magento\Framework\Registry;
+use Magento\Framework\Serialize\Serializer\Json;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Sales\Model\Order\Item;
+use Magento\Store\Model\Store;
 use Magento\Weee\Helper\Data as WeeeHelper;
+use Magento\Weee\Model\Config;
+use Magento\Weee\Model\Tax;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @SuppressWarnings(PHPMD.TooManyMethods)
  * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
-class DataTest extends \PHPUnit\Framework\TestCase
+class DataTest extends TestCase
 {
     const ROW_AMOUNT_INVOICED = '200';
     const BASE_ROW_AMOUNT_INVOICED = '400';
@@ -23,12 +36,12 @@ class DataTest extends \PHPUnit\Framework\TestCase
     const BASE_TAX_AMOUNT_REFUNDED = '21';
 
     /**
-     * @var \Magento\Catalog\Model\Product
+     * @var Product
      */
     protected $product;
 
     /**
-     * @var \Magento\Weee\Model\Tax
+     * @var Tax
      */
     protected $weeeTax;
 
@@ -42,23 +55,23 @@ class DataTest extends \PHPUnit\Framework\TestCase
      */
     protected $helperData;
 
-    /** @var \Magento\Framework\Serialize\Serializer\Json|\PHPUnit_Framework_MockObject_MockObject */
+    /** @var Json|MockObject */
     private $serializerMock;
 
-    protected function setUp()
+    protected function setUp(): void
     {
-        $this->product = $this->createMock(\Magento\Catalog\Model\Product::class);
-        $weeeConfig = $this->createMock(\Magento\Weee\Model\Config::class);
+        $this->product = $this->createMock(Product::class);
+        $weeeConfig = $this->createMock(Config::class);
         $weeeConfig->expects($this->any())->method('isEnabled')->will($this->returnValue(true));
         $weeeConfig->expects($this->any())->method('getListPriceDisplayType')->will($this->returnValue(1));
-        $this->weeeTax = $this->createMock(\Magento\Weee\Model\Tax::class);
+        $this->weeeTax = $this->createMock(Tax::class);
         $this->weeeTax->expects($this->any())->method('getWeeeAmount')->will($this->returnValue('11.26'));
         $this->taxData = $this->createPartialMock(
             \Magento\Tax\Helper\Data::class,
             ['getPriceDisplayType', 'priceIncludesTax']
         );
 
-        $this->serializerMock = $this->getMockBuilder(\Magento\Framework\Serialize\Serializer\Json::class)->getMock();
+        $this->serializerMock = $this->getMockBuilder(Json::class)->getMock();
 
         $arguments = [
             'weeeConfig' => $weeeConfig,
@@ -66,7 +79,7 @@ protected function setUp()
             'taxData' => $this->taxData,
             'serializer'  => $this->serializerMock
         ];
-        $helper = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+        $helper = new ObjectManager($this);
         $this->helperData = $helper->getObject(\Magento\Weee\Helper\Data::class, $arguments);
     }
 
@@ -79,11 +92,11 @@ public function testGetAmount()
     }
 
     /**
-     * @return \Magento\Sales\Model\Order\Item|\PHPUnit_Framework_MockObject_MockObject
+     * @return Item|MockObject
      */
     private function setupOrderItem()
     {
-        $orderItem = $this->getMockBuilder(\Magento\Sales\Model\Order\Item::class)
+        $orderItem = $this->getMockBuilder(Item::class)
             ->disableOriginalConstructor()
             ->setMethods(['__wakeup'])
             ->getMock();
@@ -192,7 +205,7 @@ public function testGetWeeeAttributesForBundle($priceDisplay, $priceIncludesTax,
         $fptCode1 = 'fpt' . $prodId1;
         $fptCode2 = 'fpt' . $prodId2;
 
-        $weeeObject1 = new \Magento\Framework\DataObject(
+        $weeeObject1 = new DataObject(
             [
                 'code' => $fptCode1,
                 'amount' => '15',
@@ -200,7 +213,7 @@ public function testGetWeeeAttributesForBundle($priceDisplay, $priceIncludesTax,
                 'tax_amount' => '1'
             ]
         );
-        $weeeObject2 = new \Magento\Framework\DataObject(
+        $weeeObject2 = new DataObject(
             [
                 'code' => $fptCode2,
                 'amount' => '10',
@@ -208,7 +221,7 @@ public function testGetWeeeAttributesForBundle($priceDisplay, $priceIncludesTax,
                 'tax_amount' => '5'
             ]
         );
-        $expectedObject1 = new \Magento\Framework\DataObject(
+        $expectedObject1 = new DataObject(
             [
                 'code' => $fptCode1,
                 'amount' => $expectedAmount[0],
@@ -216,7 +229,7 @@ public function testGetWeeeAttributesForBundle($priceDisplay, $priceIncludesTax,
                 'tax_amount' => '1'
             ]
         );
-        $expectedObject2 = new \Magento\Framework\DataObject(
+        $expectedObject2 = new DataObject(
             [
                 'code' => $fptCode2,
                 'amount' => $expectedAmount[1],
@@ -236,7 +249,7 @@ public function testGetWeeeAttributesForBundle($priceDisplay, $priceIncludesTax,
             ->method('priceIncludesTax')
             ->willReturn($priceIncludesTax);
 
-        $productSimple = $this->createPartialMock(\Magento\Catalog\Model\Product\Type\Simple::class, ['getId']);
+        $productSimple = $this->createPartialMock(Simple::class, ['getId']);
         $productSimple->expects($this->at(0))
             ->method('getId')
             ->will($this->returnValue($prodId1));
@@ -244,15 +257,15 @@ public function testGetWeeeAttributesForBundle($priceDisplay, $priceIncludesTax,
             ->method('getId')
             ->will($this->returnValue($prodId2));
 
-        $productInstance = $this->createMock(\Magento\Bundle\Model\Product\Type::class);
+        $productInstance = $this->createMock(Type::class);
         $productInstance->expects($this->any())
             ->method('getSelectionsCollection')
             ->will($this->returnValue([$productSimple]));
 
-        $store=$this->createMock(\Magento\Store\Model\Store::class);
-        /** @var \Magento\Catalog\Model\Product $product */
+        $store=$this->createMock(Store::class);
+        /** @var Product $product */
         $product = $this->createPartialMock(
-            \Magento\Catalog\Model\Product::class,
+            Product::class,
             ['getTypeInstance', 'getStoreId', 'getStore', 'getTypeId']
         );
         $product->expects($this->any())
@@ -268,7 +281,7 @@ public function testGetWeeeAttributesForBundle($priceDisplay, $priceIncludesTax,
             ->method('getTypeId')
             ->will($this->returnValue('bundle'));
 
-        $registry=$this->createMock(\Magento\Framework\Registry::class);
+        $registry=$this->createMock(Registry::class);
         $registry->expects($this->any())
             ->method('registry')
             ->with('current_product')
@@ -431,7 +444,7 @@ public function testGetRecursiveAmountBundle()
 
     public function testGetProductWeeeAttributesForDisplay()
     {
-        $store = $this->createMock(\Magento\Store\Model\Store::class);
+        $store = $this->createMock(Store::class);
         $this->product->expects($this->any())
             ->method('getStore')
             ->will($this->returnValue($store));
@@ -448,7 +461,7 @@ public function testGetTaxDisplayConfig()
         $arguments = [
             'taxData' => $taxData,
         ];
-        $helper = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+        $helper = new ObjectManager($this);
         $helperData = $helper->getObject(\Magento\Weee\Helper\Data::class, $arguments);
 
         $this->assertEquals($expected, $helperData->getTaxDisplayConfig());
diff --git a/app/code/Magento/Weee/Test/Unit/Model/Attribute/Backend/Weee/TaxTest.php b/app/code/Magento/Weee/Test/Unit/Model/Attribute/Backend/Weee/TaxTest.php
index 7170969f5953e..804d686a8075a 100644
--- a/app/code/Magento/Weee/Test/Unit/Model/Attribute/Backend/Weee/TaxTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Model/Attribute/Backend/Weee/TaxTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -9,16 +9,20 @@
  */
 namespace Magento\Weee\Test\Unit\Model\Attribute\Backend\Weee;
 
+use Magento\Catalog\Model\Product;
+use Magento\Eav\Model\Attribute;
 use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Weee\Model\Attribute\Backend\Weee\Tax;
+use PHPUnit\Framework\TestCase;
 
-class TaxTest extends \PHPUnit\Framework\TestCase
+class TaxTest extends TestCase
 {
     /**
      * @var ObjectManager
      */
     protected $objectManager;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->objectManager = new ObjectManager($this);
     }
@@ -26,8 +30,8 @@ protected function setUp()
     public function testGetBackendModelName()
     {
         $this->assertEquals(
-            \Magento\Weee\Model\Attribute\Backend\Weee\Tax::class,
-            \Magento\Weee\Model\Attribute\Backend\Weee\Tax::getBackendModelName()
+            Tax::class,
+            Tax::getBackendModelName()
         );
     }
 
@@ -38,7 +42,7 @@ public function testGetBackendModelName()
      */
     public function testValidate($data, $expected)
     {
-        $attributeMock = $this->getMockBuilder(\Magento\Eav\Model\Attribute::class)
+        $attributeMock = $this->getMockBuilder(Attribute::class)
             ->setMethods(['getName'])
             ->disableOriginalConstructor()
             ->getMock();
@@ -47,7 +51,7 @@ public function testValidate($data, $expected)
             ->method('getName')
             ->will($this->returnValue('weeeTax'));
 
-        $modelMock = $this->getMockBuilder(\Magento\Weee\Model\Attribute\Backend\Weee\Tax::class)
+        $modelMock = $this->getMockBuilder(Tax::class)
             ->setMethods(['getAttribute'])
             ->disableOriginalConstructor()
             ->getMock();
@@ -57,7 +61,7 @@ public function testValidate($data, $expected)
             ->will($this->returnValue($attributeMock));
 
         $taxes = [reset($data)];
-        $productMock = $this->getMockBuilder(\Magento\Catalog\Model\Product::class)
+        $productMock = $this->getMockBuilder(Product::class)
             ->setMethods(['getData'])
             ->disableOriginalConstructor()
             ->getMock();
@@ -70,7 +74,7 @@ public function testValidate($data, $expected)
         $modelMock->validate($productMock);
 
         $taxes = $data;
-        $productMock = $this->getMockBuilder(\Magento\Catalog\Model\Product::class)
+        $productMock = $this->getMockBuilder(Product::class)
             ->setMethods(['getData'])
             ->disableOriginalConstructor()
             ->getMock();
@@ -117,7 +121,7 @@ public function testAfterLoad()
             ->method('loadProductData')
             ->will($this->returnValue($data));
 
-        $attributeMock = $this->getMockBuilder(\Magento\Eav\Model\Attribute::class)
+        $attributeMock = $this->getMockBuilder(Attribute::class)
             ->setMethods(['getName'])
             ->disableOriginalConstructor()
             ->getMock();
@@ -127,7 +131,7 @@ public function testAfterLoad()
             ->will($this->returnValue('weeeTax'));
 
         $model = $this->objectManager->getObject(
-            \Magento\Weee\Model\Attribute\Backend\Weee\Tax::class,
+            Tax::class,
             [
                 'attributeTax' => $attributeTaxMock,
                 '_attribute' => $attributeMock
@@ -135,7 +139,7 @@ public function testAfterLoad()
         );
 
         $model->setAttribute($attributeMock);
-        $productMock = $this->getMockBuilder(\Magento\Catalog\Model\Product::class)
+        $productMock = $this->getMockBuilder(Product::class)
             ->setMethods(['setData'])
             ->disableOriginalConstructor()
             ->getMock();
@@ -154,7 +158,7 @@ public function testAfterLoad()
      */
     public function testAfterSaveWithRegion($origData, $currentData, $expectedData)
     {
-        $productMock = $this->getMockBuilder(\Magento\Catalog\Model\Product::class)
+        $productMock = $this->getMockBuilder(Product::class)
             ->setMethods(['getOrigData', 'getData'])
             ->disableOriginalConstructor()
             ->getMock();
@@ -182,7 +186,7 @@ public function testAfterSaveWithRegion($origData, $currentData, $expectedData)
             ->with($productMock, $expectedData)
             ->will($this->returnValue(null));
 
-        $attributeMock = $this->getMockBuilder(\Magento\Eav\Model\Attribute::class)
+        $attributeMock = $this->getMockBuilder(Attribute::class)
             ->setMethods(['getName', 'getId'])
             ->disableOriginalConstructor()
             ->getMock();
@@ -196,7 +200,7 @@ public function testAfterSaveWithRegion($origData, $currentData, $expectedData)
             ->will($this->returnValue(1));
 
         $model = $this->objectManager->getObject(
-            \Magento\Weee\Model\Attribute\Backend\Weee\Tax::class,
+            Tax::class,
             [
                 'attributeTax' => $attributeTaxMock,
                 '_attribute' => $attributeMock
@@ -239,7 +243,7 @@ public function testAfterDelete()
             ->will($this->returnValue(null));
 
         $model = $this->objectManager->getObject(
-            \Magento\Weee\Model\Attribute\Backend\Weee\Tax::class,
+            Tax::class,
             [
                 'attributeTax' => $attributeTaxMock,
             ]
@@ -261,7 +265,7 @@ public function testGetTable()
             ->will($this->returnValue(null));
 
         $model = $this->objectManager->getObject(
-            \Magento\Weee\Model\Attribute\Backend\Weee\Tax::class,
+            Tax::class,
             [
                 'attributeTax' => $attributeTaxMock,
             ]
@@ -288,7 +292,7 @@ public function testGetEntityIdField() : void
             ->willReturn(null);
 
         $model = $this->objectManager->getObject(
-            \Magento\Weee\Model\Attribute\Backend\Weee\Tax::class,
+            Tax::class,
             [
                 'attributeTax' => $attributeTaxMock,
             ]
diff --git a/app/code/Magento/Weee/Test/Unit/Model/ConfigTest.php b/app/code/Magento/Weee/Test/Unit/Model/ConfigTest.php
index a5663ec35e59c..52ad266c31ea3 100644
--- a/app/code/Magento/Weee/Test/Unit/Model/ConfigTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Model/ConfigTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -9,9 +9,13 @@
  */
 namespace Magento\Weee\Test\Unit\Model;
 
-use \Magento\Weee\Model\Config;
+use Magento\Framework\App\Config\ScopeConfigInterface;
+use Magento\Store\Model\ScopeInterface;
+use Magento\Tax\Helper\Data;
+use Magento\Weee\Model\Config;
+use PHPUnit\Framework\TestCase;
 
-class ConfigTest extends \PHPUnit\Framework\TestCase
+class ConfigTest extends TestCase
 {
     /**
      * Tests the methods that rely on the ScopeConfigInterface object to provide their return values
@@ -24,19 +28,19 @@ class ConfigTest extends \PHPUnit\Framework\TestCase
      */
     public function testScopeConfigMethods($method, $path, $configValue, $expectedValue)
     {
-        $scopeConfigMock = $this->getMockForAbstractClass(\Magento\Framework\App\Config\ScopeConfigInterface::class);
+        $scopeConfigMock = $this->getMockForAbstractClass(ScopeConfigInterface::class);
         $scopeConfigMock->expects($this->any())
             ->method('getValue')
-            ->with($path, \Magento\Store\Model\ScopeInterface::SCOPE_STORE, null)
+            ->with($path, ScopeInterface::SCOPE_STORE, null)
             ->will($this->returnValue($configValue));
         $scopeConfigMock->expects($this->any())
             ->method('isSetFlag')
-            ->with($path, \Magento\Store\Model\ScopeInterface::SCOPE_STORE, null)
+            ->with($path, ScopeInterface::SCOPE_STORE, null)
             ->will($this->returnValue($configValue));
 
-        $taxData = $this->createMock(\Magento\Tax\Helper\Data::class);
+        $taxData = $this->createMock(Data::class);
 
-        /** @var \Magento\Weee\Model\Config */
+        /** @var Config */
         $model = new Config($scopeConfigMock, $taxData);
         $this->assertEquals($expectedValue, $model->{$method}());
     }
diff --git a/app/code/Magento/Weee/Test/Unit/Model/ResourceModel/Attribute/Backend/Weee/TaxTest.php b/app/code/Magento/Weee/Test/Unit/Model/ResourceModel/Attribute/Backend/Weee/TaxTest.php
index 01de2b8f7934e..b954d648532c2 100644
--- a/app/code/Magento/Weee/Test/Unit/Model/ResourceModel/Attribute/Backend/Weee/TaxTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Model/ResourceModel/Attribute/Backend/Weee/TaxTest.php
@@ -1,38 +1,47 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Model\ResourceModel\Attribute\Backend\Weee;
 
-class TaxTest extends \PHPUnit\Framework\TestCase
+use Magento\Catalog\Model\Product;
+use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use Magento\Framework\Model\ResourceModel\Db\Context;
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\Weee\Model\ResourceModel\Attribute\Backend\Weee\Tax;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+
+class TaxTest extends TestCase
 {
     /**
-     * @var \Magento\Weee\Model\ResourceModel\Attribute\Backend\Weee\Tax
+     * @var Tax
      */
     protected $model;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $resourceMock;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $storeManagerMock;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $connectionMock;
 
-    protected function setUp()
+    protected function setUp(): void
     {
-        $this->storeManagerMock = $this->createMock(\Magento\Store\Model\StoreManagerInterface::class);
-        $this->connectionMock = $this->createMock(\Magento\Framework\DB\Adapter\AdapterInterface::class);
+        $this->storeManagerMock = $this->createMock(StoreManagerInterface::class);
+        $this->connectionMock = $this->createMock(AdapterInterface::class);
 
-        $this->resourceMock = $this->createMock(\Magento\Framework\App\ResourceConnection::class);
+        $this->resourceMock = $this->createMock(ResourceConnection::class);
         $this->resourceMock->expects($this->once())
             ->method('getConnection')
             ->willReturn($this->connectionMock);
@@ -41,10 +50,10 @@ protected function setUp()
             ->method('getTableName')
             ->willReturn('table_name');
 
-        $contextMock = $this->createMock(\Magento\Framework\Model\ResourceModel\Db\Context::class);
+        $contextMock = $this->createMock(Context::class);
         $contextMock->expects($this->once())->method('getResources')->willReturn($this->resourceMock);
 
-        $this->model = new \Magento\Weee\Model\ResourceModel\Attribute\Backend\Weee\Tax(
+        $this->model = new Tax(
             $contextMock,
             $this->storeManagerMock
         );
@@ -53,7 +62,7 @@ protected function setUp()
     public function testInsertProductData()
     {
         $productId = 100;
-        $productMock = $this->createPartialMock(\Magento\Catalog\Model\Product::class, ['getId']);
+        $productMock = $this->createPartialMock(Product::class, ['getId']);
         $productMock->expects($this->once())->method('getId')->willReturn($productId);
 
         $this->connectionMock->expects($this->once())
diff --git a/app/code/Magento/Weee/Test/Unit/Model/ResourceModel/TaxTest.php b/app/code/Magento/Weee/Test/Unit/Model/ResourceModel/TaxTest.php
index abb2e3f1e2438..3744fd2876114 100644
--- a/app/code/Magento/Weee/Test/Unit/Model/ResourceModel/TaxTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Model/ResourceModel/TaxTest.php
@@ -1,51 +1,61 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Model\ResourceModel;
 
-class TaxTest extends \PHPUnit\Framework\TestCase
+use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use Magento\Framework\DB\Select;
+use Magento\Framework\Model\ResourceModel\Db\Context;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\Weee\Model\ResourceModel\Tax;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+
+class TaxTest extends TestCase
 {
     /**
-     * @var \Magento\Weee\Model\ResourceModel\Tax
+     * @var Tax
      */
     protected $model;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $resourceMock;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $storeManagerMock;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $connectionMock;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $selectMock;
 
-    protected function setUp()
+    protected function setUp(): void
     {
-        $this->objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+        $objectManager = new ObjectManager($this);
 
-        $this->storeManagerMock = $this->createMock(\Magento\Store\Model\StoreManagerInterface::class);
+        $this->storeManagerMock = $this->createMock(StoreManagerInterface::class);
 
-        $this->selectMock = $this->createMock(\Magento\Framework\DB\Select::class);
+        $this->selectMock = $this->createMock(Select::class);
 
-        $this->connectionMock = $this->createMock(\Magento\Framework\DB\Adapter\AdapterInterface::class);
+        $this->connectionMock = $this->createMock(AdapterInterface::class);
         $this->connectionMock->expects($this->once())
             ->method('select')
             ->willReturn($this->selectMock);
 
-        $this->resourceMock = $this->createMock(\Magento\Framework\App\ResourceConnection::class);
+        $this->resourceMock = $this->createMock(ResourceConnection::class);
         $this->resourceMock->expects($this->any())
             ->method('getConnection')
             ->willReturn($this->connectionMock);
@@ -54,11 +64,11 @@ protected function setUp()
             ->method('getTableName')
             ->willReturn('table_name');
 
-        $contextMock = $this->createMock(\Magento\Framework\Model\ResourceModel\Db\Context::class);
+        $contextMock = $this->createMock(Context::class);
         $contextMock->expects($this->any())->method('getResources')->willReturn($this->resourceMock);
 
-        $this->model = $this->objectManager->getObject(
-            \Magento\Weee\Model\ResourceModel\Tax::class,
+        $this->model = $objectManager->getObject(
+            Tax::class,
             [
                 'context' => $contextMock,
             ]
diff --git a/app/code/Magento/Weee/Test/Unit/Model/TaxTest.php b/app/code/Magento/Weee/Test/Unit/Model/TaxTest.php
index ac90dfade07e2..9377da2ec65b8 100644
--- a/app/code/Magento/Weee/Test/Unit/Model/TaxTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Model/TaxTest.php
@@ -1,115 +1,136 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Model;
 
+use Magento\Catalog\Model\Product;
+use Magento\Customer\Api\AccountManagementInterface;
+use Magento\Customer\Model\Session;
+use Magento\Eav\Model\Entity\Attribute;
+use Magento\Eav\Model\Entity\AttributeFactory;
+use Magento\Framework\Data\Collection\AbstractDb;
+use Magento\Framework\DataObject;
+use Magento\Framework\Model\Context;
+use Magento\Framework\Pricing\PriceCurrencyInterface;
+use Magento\Framework\Registry;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Store\Model\Group;
+use Magento\Store\Model\Store;
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\Store\Model\Website;
+use Magento\Tax\Helper\Data;
+use Magento\Tax\Model\Calculation;
+use Magento\Tax\Model\CalculationFactory;
+use Magento\Weee\Model\Config;
+use Magento\Weee\Model\Tax;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+
 /**
- * Class TaxTest
- *
  * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
-class TaxTest extends \PHPUnit\Framework\TestCase
+class TaxTest extends TestCase
 {
     /**
-     * @var \Magento\Weee\Model\Tax
+     * @var Tax
      */
     protected $model;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $context;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $registry;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $attributeFactory;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $storeManager;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $calculationFactory;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $customerSession;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $accountManagement;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $taxData;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $resource;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $weeeConfig;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $priceCurrency;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $resourceCollection;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $data;
 
     /**
-     * @var \Magento\Framework\TestFramework\Unit\Helper\ObjectManager
+     * @var ObjectManager
      */
     protected $objectManager;
 
     /**
      * Setup the test
      */
-    protected function setUp()
+    protected function setUp(): void
     {
-        $this->objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+        $this->objectManager = new ObjectManager($this);
 
-        $className = \Magento\Framework\Model\Context::class;
+        $className = Context::class;
         $this->context = $this->createMock($className);
 
-        $className = \Magento\Framework\Registry::class;
+        $className = Registry::class;
         $this->registry = $this->createMock($className);
 
-        $className = \Magento\Eav\Model\Entity\AttributeFactory::class;
+        $className = AttributeFactory::class;
         $this->attributeFactory = $this->createPartialMock($className, ['create']);
 
-        $className = \Magento\Store\Model\StoreManagerInterface::class;
+        $className = StoreManagerInterface::class;
         $this->storeManager = $this->createMock($className);
 
-        $className = \Magento\Tax\Model\CalculationFactory::class;
+        $className = CalculationFactory::class;
         $this->calculationFactory = $this->createPartialMock($className, ['create']);
 
-        $className = \Magento\Customer\Model\Session::class;
+        $className = Session::class;
         $this->customerSession = $this->createPartialMock(
             $className,
             ['getCustomerId', 'getDefaultTaxShippingAddress', 'getDefaultTaxBillingAddress', 'getCustomerTaxClassId']
@@ -119,26 +140,26 @@ protected function setUp()
         $this->customerSession->expects($this->any())->method('getDefaultTaxBillingAddress')->willReturn(null);
         $this->customerSession->expects($this->any())->method('getCustomerTaxClassId')->willReturn(null);
 
-        $className = \Magento\Customer\Api\AccountManagementInterface::class;
+        $className = AccountManagementInterface::class;
         $this->accountManagement = $this->createMock($className);
 
-        $className = \Magento\Tax\Helper\Data::class;
+        $className = Data::class;
         $this->taxData = $this->createMock($className);
 
         $className = \Magento\Weee\Model\ResourceModel\Tax::class;
         $this->resource = $this->createMock($className);
 
-        $className = \Magento\Weee\Model\Config::class;
+        $className = Config::class;
         $this->weeeConfig = $this->createMock($className);
 
-        $className = \Magento\Framework\Pricing\PriceCurrencyInterface::class;
+        $className = PriceCurrencyInterface::class;
         $this->priceCurrency = $this->createMock($className);
 
-        $className = \Magento\Framework\Data\Collection\AbstractDb::class;
+        $className = AbstractDb::class;
         $this->resourceCollection = $this->createMock($className);
 
         $this->model = $this->objectManager->getObject(
-            \Magento\Weee\Model\Tax::class,
+            Tax::class,
             [
                 'context' => $this->context,
                 'registry' => $this->registry,
@@ -168,15 +189,15 @@ public function testGetProductWeeeAttributes(
         $websitePassed,
         string $expectedFptLabel
     ): void {
-        $product = $this->createMock(\Magento\Catalog\Model\Product::class);
-        $website = $this->createMock(\Magento\Store\Model\Website::class);
-        $store = $this->createMock(\Magento\Store\Model\Store::class);
-        $group = $this->createMock(\Magento\Store\Model\Group::class);
+        $product = $this->createMock(Product::class);
+        $website = $this->createMock(Website::class);
+        $store = $this->createMock(Store::class);
+        $group = $this->createMock(Group::class);
 
-        $attribute = $this->createMock(\Magento\Eav\Model\Entity\Attribute::class);
-        $calculation = $this->createMock(\Magento\Tax\Model\Calculation::class);
+        $attribute = $this->createMock(Attribute::class);
+        $calculation = $this->createMock(Calculation::class);
 
-        $obj = new \Magento\Framework\DataObject(['country' => 'US', 'region' => 'TX']);
+        $obj = new DataObject(['country' => 'US', 'region' => 'TX']);
         $calculation->expects($this->once())
             ->method('getRateRequest')
             ->willReturn($obj);
@@ -270,19 +291,19 @@ public function testGetProductWeeeAttributes(
      */
     public function testGetWeeeAmountExclTax($productTypeId, $productPriceType)
     {
-        $product = $this->getMockBuilder(\Magento\Catalog\Model\Product::class)
+        $product = $this->getMockBuilder(Product::class)
             ->disableOriginalConstructor()
             ->setMethods(['getTypeId', 'getPriceType'])
             ->getMock();
         $product->expects($this->any())->method('getTypeId')->willReturn($productTypeId);
         $product->expects($this->any())->method('getPriceType')->willReturn($productPriceType);
-        $weeeDataHelper = $this->getMockBuilder(\Magento\Framework\DataObject::class)
+        $weeeDataHelper = $this->getMockBuilder(DataObject::class)
             ->disableOriginalConstructor()
             ->setMethods(['getAmountExclTax'])
             ->getMock();
         $weeeDataHelper->expects($this->at(0))->method('getAmountExclTax')->willReturn(10);
         $weeeDataHelper->expects($this->at(1))->method('getAmountExclTax')->willReturn(30);
-        $tax = $this->getMockBuilder(\Magento\Weee\Model\Tax::class)
+        $tax = $this->getMockBuilder(Tax::class)
             ->disableOriginalConstructor()
             ->setMethods(['getProductWeeeAttributes'])
             ->getMock();
@@ -296,16 +317,16 @@ public function testGetWeeeAmountExclTax($productTypeId, $productPriceType)
      */
     public function testGetWeeeAmountExclTaxForDynamicBundleProduct()
     {
-        $product = $this->getMockBuilder(\Magento\Catalog\Model\Product::class)
+        $product = $this->getMockBuilder(Product::class)
             ->disableOriginalConstructor()
             ->setMethods(['getTypeId', 'getPriceType'])
             ->getMock();
         $product->expects($this->once())->method('getTypeId')->willReturn('bundle');
         $product->expects($this->once())->method('getPriceType')->willReturn(0);
-        $weeeDataHelper = $this->getMockBuilder(\Magento\Framework\DataObject::class)
+        $weeeDataHelper = $this->getMockBuilder(DataObject::class)
             ->disableOriginalConstructor()
             ->getMock();
-        $tax = $this->getMockBuilder(\Magento\Weee\Model\Tax::class)
+        $tax = $this->getMockBuilder(Tax::class)
             ->disableOriginalConstructor()
             ->setMethods(['getProductWeeeAttributes'])
             ->getMock();
diff --git a/app/code/Magento/Weee/Test/Unit/Model/Total/Creditmemo/WeeeTest.php b/app/code/Magento/Weee/Test/Unit/Model/Total/Creditmemo/WeeeTest.php
index 409dd93cb2050..d0824a662598f 100644
--- a/app/code/Magento/Weee/Test/Unit/Model/Total/Creditmemo/WeeeTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Model/Total/Creditmemo/WeeeTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -6,42 +6,52 @@
 namespace Magento\Weee\Test\Unit\Model\Total\Creditmemo;
 
 use Magento\Framework\Serialize\Serializer\Json;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Sales\Model\Order;
+use Magento\Sales\Model\Order\Creditmemo;
+use Magento\Sales\Model\Order\Invoice;
+use Magento\Sales\Model\Order\Invoice\Item;
+use Magento\Sales\Model\Order\Invoice\Total\Tax;
+use Magento\Weee\Helper\Data;
+use Magento\Weee\Model\Total\Creditmemo\Weee;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
 
-class WeeeTest extends \PHPUnit\Framework\TestCase
+class WeeeTest extends TestCase
 {
     /**
-     * @var \Magento\Weee\Model\Total\Creditmemo\Weee
+     * @var Weee
      */
     protected $model;
 
     /**
-     * @var \Magento\Sales\Model\Order|\PHPUnit_Framework_MockObject_MockObject
+     * @var Order|MockObject
      */
     protected $order;
 
     /**
-     * @var  \Magento\Framework\TestFramework\Unit\Helper\ObjectManager
+     * @var  ObjectManager
      */
     protected $objectManager;
 
     /**
-     * @var \Magento\Sales\Model\Order\Creditmemo|\PHPUnit_Framework_MockObject_MockObject
+     * @var Creditmemo|MockObject
      */
     protected $creditmemo;
 
     /**
-     * @var \Magento\Sales\Model\Order\Invoice|\PHPUnit_Framework_MockObject_MockObject
+     * @var Invoice|MockObject
      */
     protected $invoice;
 
     /**
-     * @var \Magento\Weee\Helper\Data|\PHPUnit_Framework_MockObject_MockObject
+     * @var Data|MockObject
      */
     protected $weeeData;
 
-    protected function setUp()
+    protected function setUp(): void
     {
-        $this->weeeData = $this->getMockBuilder(\Magento\Weee\Helper\Data::class)
+        $this->weeeData = $this->getMockBuilder(Data::class)
             ->setMethods(
                 [
                     'getRowWeeeTaxInclTax',
@@ -61,22 +71,22 @@ protected function setUp()
             )->disableOriginalConstructor()
             ->getMock();
 
-        $this->objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+        $this->objectManager = new ObjectManager($this);
         $serializer = $this->objectManager->getObject(Json::class);
-        /** @var \Magento\Sales\Model\Order\Invoice\Total\Tax $model */
+        /** @var Tax $model */
         $this->model = $this->objectManager->getObject(
-            \Magento\Weee\Model\Total\Creditmemo\Weee::class,
+            Weee::class,
             [
                 'weeeData' => $this->weeeData,
                 'serializer' => $serializer
             ]
         );
 
-        $this->order = $this->createPartialMock(\Magento\Sales\Model\Order::class, [
+        $this->order = $this->createPartialMock(Order::class, [
                 '__wakeup'
             ]);
 
-        $this->creditmemo = $this->createPartialMock(\Magento\Sales\Model\Order\Creditmemo::class, [
+        $this->creditmemo = $this->createPartialMock(Creditmemo::class, [
                 'getAllItems',
                 'getInvoice',
                 'roundPrice',
@@ -100,7 +110,7 @@ public function testCollect($creditmemoData, $expectedResults)
             ->will($this->returnValue($creditmemoData['include_in_subtotal']));
 
         //Set up invoice mock
-        /** @var \Magento\Sales\Model\Order\Invoice\Item[] $creditmemoItems */
+        /** @var Item[] $creditmemoItems */
         $creditmemoItems = [];
         foreach ($creditmemoData['items'] as $itemKey => $creditmemoItemData) {
             $creditmemoItems[$itemKey] = $this->getInvoiceItem($creditmemoItemData);
@@ -132,7 +142,7 @@ function ($price, $type) use (&$roundingDelta) {
             $this->assertEquals(
                 $value,
                 $this->creditmemo->getData($key),
-                'Creditmemo data field '.$key.' is incorrect'
+                'Creditmemo data field ' . $key . ' is incorrect'
             );
         }
         //verify invoice item data
@@ -146,7 +156,7 @@ function ($price, $type) use (&$roundingDelta) {
                     $this->assertEquals(
                         $value,
                         $creditmemoItem->getData($key),
-                        'Creditmemo item field '.$key.' is incorrect'
+                        'Creditmemo item field ' . $key . ' is incorrect'
                     );
                 }
             }
@@ -485,11 +495,11 @@ public function collectDataProvider()
 
     /**
      * @param $creditmemoItemData array
-     * @return \Magento\Sales\Model\Order\Creditmemo\Item|\PHPUnit_Framework_MockObject_MockObject
+     * @return \Magento\Sales\Model\Order\Creditmemo\Item|MockObject
      */
     protected function getInvoiceItem($creditmemoItemData)
     {
-        /** @var \Magento\Sales\Model\Order\Item|\PHPUnit_Framework_MockObject_MockObject $orderItem */
+        /** @var \Magento\Sales\Model\Order\Item|MockObject $orderItem */
         $orderItem = $this->createPartialMock(\Magento\Sales\Model\Order\Item::class, [
                 'isDummy',
                 '__wakeup'
@@ -539,8 +549,8 @@ protected function getInvoiceItem($creditmemoItemData)
             ->with($orderItem)
             ->will($this->returnValue($orderItem->getBaseWeeeTaxAmountRefunded()));
 
-        /** @var \Magento\Sales\Model\Order\Invoice\Item|\PHPUnit_Framework_MockObject_MockObject $invoiceItem */
-        $invoiceItem = $this->createPartialMock(\Magento\Sales\Model\Order\Invoice\Item::class, [
+        /** @var Item|MockObject $invoiceItem */
+        $invoiceItem = $this->createPartialMock(Item::class, [
                 'getOrderItem',
                 'isLast',
                 '__wakeup'
diff --git a/app/code/Magento/Weee/Test/Unit/Model/Total/Invoice/WeeeTest.php b/app/code/Magento/Weee/Test/Unit/Model/Total/Invoice/WeeeTest.php
index 22d673e0c8b26..8d3b334b5125c 100644
--- a/app/code/Magento/Weee/Test/Unit/Model/Total/Invoice/WeeeTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Model/Total/Invoice/WeeeTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -6,37 +6,46 @@
 namespace Magento\Weee\Test\Unit\Model\Total\Invoice;
 
 use Magento\Framework\Serialize\Serializer\Json;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Sales\Model\Order;
+use Magento\Sales\Model\Order\Invoice;
+use Magento\Sales\Model\Order\Invoice\Item;
+use Magento\Sales\Model\Order\Invoice\Total\Tax;
+use Magento\Weee\Helper\Data;
+use Magento\Weee\Model\Total\Invoice\Weee;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
 
-class WeeeTest extends \PHPUnit\Framework\TestCase
+class WeeeTest extends TestCase
 {
     /**
-     * @var \Magento\Weee\Model\Total\Invoice\Weee
+     * @var Weee
      */
     protected $model;
 
     /**
-     * @var \Magento\Sales\Model\Order|\PHPUnit_Framework_MockObject_MockObject
+     * @var Order|MockObject
      */
     protected $order;
 
     /**
-     * @var  \Magento\Framework\TestFramework\Unit\Helper\ObjectManager
+     * @var  ObjectManager
      */
     protected $objectManager;
 
     /**
-     * @var \Magento\Sales\Model\Order\Invoice|\PHPUnit_Framework_MockObject_MockObject
+     * @var Invoice|MockObject
      */
     protected $invoice;
 
     /**
-     * @var \Magento\Weee\Helper\Data|\PHPUnit_Framework_MockObject_MockObject
+     * @var Data|MockObject
      */
     protected $weeeData;
 
-    protected function setUp()
+    protected function setUp(): void
     {
-        $this->weeeData = $this->getMockBuilder(\Magento\Weee\Helper\Data::class)
+        $this->weeeData = $this->getMockBuilder(Data::class)
             ->setMethods(
                 [
                     'getRowWeeeTaxInclTax',
@@ -52,22 +61,22 @@ protected function setUp()
             )->disableOriginalConstructor()
             ->getMock();
 
-        $this->objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+        $this->objectManager = new ObjectManager($this);
         $serializer = $this->objectManager->getObject(Json::class);
-        /** @var \Magento\Sales\Model\Order\Invoice\Total\Tax $model */
+        /** @var Tax $model */
         $this->model = $this->objectManager->getObject(
-            \Magento\Weee\Model\Total\Invoice\Weee::class,
+            Weee::class,
             [
                 'weeeData' => $this->weeeData,
                 'serializer' => $serializer
             ]
         );
 
-        $this->order = $this->createPartialMock(\Magento\Sales\Model\Order::class, [
+        $this->order = $this->createPartialMock(Order::class, [
                 '__wakeup'
             ]);
 
-        $this->invoice = $this->createPartialMock(\Magento\Sales\Model\Order\Invoice::class, [
+        $this->invoice = $this->createPartialMock(Invoice::class, [
                 'getAllItems',
                 'getOrder',
                 'roundPrice',
@@ -107,7 +116,7 @@ public function testCollect($orderData, $invoiceData, $expectedResults)
             ->will($this->returnValue($invoiceData['include_in_subtotal']));
 
         //Set up invoice mock
-        /** @var \Magento\Sales\Model\Order\Invoice\Item[] $invoiceItems */
+        /** @var Item[] $invoiceItems */
         $invoiceItems = [];
         foreach ($invoiceData['items'] as $itemKey => $invoiceItemData) {
             $invoiceItems[$itemKey] = $this->getInvoiceItem($invoiceItemData);
@@ -139,7 +148,7 @@ function ($price, $type) use (&$roundingDelta) {
 
         //verify invoice data
         foreach ($expectedResults['invoice_data'] as $key => $value) {
-            $this->assertEquals($value, $this->invoice->getData($key), 'Invoice data field '.$key.' is incorrect');
+            $this->assertEquals($value, $this->invoice->getData($key), 'Invoice data field ' . $key . ' is incorrect');
         }
         //verify invoice item data
         foreach ($expectedResults['invoice_items'] as $itemKey => $itemData) {
@@ -152,7 +161,7 @@ function ($price, $type) use (&$roundingDelta) {
                     $this->assertEquals(
                         $value,
                         $invoiceItem->getData($key),
-                        'Invoice item field '.$key.' is incorrect'
+                        'Invoice item field ' . $key . ' is incorrect'
                     );
                 }
             }
@@ -671,11 +680,11 @@ public function collectDataProvider()
 
     /**
      * @param $invoiceItemData array
-     * @return \Magento\Sales\Model\Order\Invoice\Item|\PHPUnit_Framework_MockObject_MockObject
+     * @return Item|MockObject
      */
     protected function getInvoiceItem($invoiceItemData)
     {
-        /** @var \Magento\Sales\Model\Order\Item|\PHPUnit_Framework_MockObject_MockObject $orderItem */
+        /** @var \Magento\Sales\Model\Order\Item|MockObject $orderItem */
         $orderItem = $this->createPartialMock(\Magento\Sales\Model\Order\Item::class, [
                 'isDummy',
                 '__wakeup'
@@ -710,8 +719,8 @@ protected function getInvoiceItem($invoiceItemData)
                 ->with($orderItem)
                 ->will($this->returnValue($orderItem->getBaseWeeeTaxAmountInvoiced()));
         }
-        /** @var \Magento\Sales\Model\Order\Invoice\Item|\PHPUnit_Framework_MockObject_MockObject $invoiceItem */
-        $invoiceItem = $this->createPartialMock(\Magento\Sales\Model\Order\Invoice\Item::class, [
+        /** @var Item|MockObject $invoiceItem */
+        $invoiceItem = $this->createPartialMock(Item::class, [
                 'getOrderItem',
                 'isLast',
                 '__wakeup'
diff --git a/app/code/Magento/Weee/Test/Unit/Model/Total/Quote/WeeeTaxTest.php b/app/code/Magento/Weee/Test/Unit/Model/Total/Quote/WeeeTaxTest.php
index 51cba29199abb..abb242cc9db6c 100644
--- a/app/code/Magento/Weee/Test/Unit/Model/Total/Quote/WeeeTaxTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Model/Total/Quote/WeeeTaxTest.php
@@ -1,17 +1,30 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Model\Total\Quote;
 
+use Magento\Catalog\Model\Product;
+use Magento\Framework\Serialize\Serializer\Json;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Quote\Api\Data\ShippingAssignmentInterface;
+use Magento\Quote\Api\Data\ShippingInterface;
+use Magento\Quote\Model\Quote;
+use Magento\Quote\Model\Quote\Address;
+use Magento\Quote\Model\Quote\Address\Total;
+use Magento\Quote\Model\Quote\Item;
+use Magento\Tax\Helper\Data;
 use Magento\Tax\Model\Calculation;
 use Magento\Tax\Model\Sales\Total\Quote\CommonTaxCollector as CTC;
+use Magento\Weee\Model\Total\Quote\WeeeTax;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
-class WeeeTaxTest extends \PHPUnit\Framework\TestCase
+class WeeeTaxTest extends TestCase
 {
     /**#@+
      * Constants for array keys
@@ -19,14 +32,13 @@ class WeeeTaxTest extends \PHPUnit\Framework\TestCase
     const KEY_WEEE_TOTALS = 'weee_total_excl_tax';
     const KEY_WEEE_BASE_TOTALS = 'weee_base_total_excl_tax';
     /**#@-*/
-
     /**
-     * @var \Magento\Weee\Model\Total\Quote\WeeeTax
+     * @var WeeeTax
      */
     protected $weeeCollector;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject | \Magento\Quote\Model\Quote
+     * @var MockObject|Quote
      */
     protected $quoteMock;
 
@@ -35,21 +47,21 @@ class WeeeTaxTest extends \PHPUnit\Framework\TestCase
      */
     protected $objectManagerHelper;
 
-    protected function setUp()
+    protected function setUp(): void
     {
-        $this->objectManagerHelper = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
-        $this->quoteMock = $this->createMock(\Magento\Quote\Model\Quote::class);
+        $this->objectManagerHelper = new ObjectManager($this);
+        $this->quoteMock = $this->createMock(Quote::class);
     }
 
     /**
      * Setup tax helper with an array of methodName, returnValue
      *
      * @param array $taxConfig
-     * @return \PHPUnit_Framework_MockObject_MockObject|\Magento\Tax\Helper\Data
+     * @return MockObject|\Magento\Tax\Helper\Data
      */
     protected function setupTaxHelper($taxConfig)
     {
-        $taxHelper = $this->createMock(\Magento\Tax\Helper\Data::class);
+        $taxHelper = $this->createMock(Data::class);
 
         foreach ($taxConfig as $method => $value) {
             $taxHelper->expects($this->any())->method($method)->will($this->returnValue($value));
@@ -62,7 +74,7 @@ protected function setupTaxHelper($taxConfig)
      * Setup weee helper with an array of methodName, returnValue
      *
      * @param array $weeeConfig
-     * @return \PHPUnit_Framework_MockObject_MockObject|\Magento\Weee\Helper\Data
+     * @return MockObject|\Magento\Weee\Helper\Data
      */
     protected function setupWeeeHelper($weeeConfig)
     {
@@ -79,11 +91,11 @@ protected function setupWeeeHelper($weeeConfig)
      * Setup an item mock
      *
      * @param float $itemQty
-     * @return \PHPUnit_Framework_MockObject_MockObject|\Magento\Quote\Model\Quote\Item
+     * @return MockObject|Item
      */
     protected function setupItemMock($itemQty)
     {
-        $itemMock = $this->createPartialMock(\Magento\Quote\Model\Quote\Item::class, [
+        $itemMock = $this->createPartialMock(Item::class, [
                 'getProduct',
                 'getQuote',
                 'getAddress',
@@ -91,7 +103,7 @@ protected function setupItemMock($itemQty)
                 '__wakeup',
             ]);
 
-        $productMock = $this->createMock(\Magento\Catalog\Model\Product::class);
+        $productMock = $this->createMock(Product::class);
         $itemMock->expects($this->any())->method('getProduct')->will($this->returnValue($productMock));
         $itemMock->expects($this->any())->method('getTotalQty')->will($this->returnValue($itemQty));
 
@@ -101,15 +113,15 @@ protected function setupItemMock($itemQty)
     /**
      * Setup address mock
      *
-     * @param \PHPUnit_Framework_MockObject_MockObject|\Magento\Quote\Model\Quote\Item $itemMock
+     * @param MockObject|Item $itemMock
      * @param boolean $isWeeeTaxable
      * @param array   $itemWeeeTaxDetails
      * @param array   $addressData
-     * @return \PHPUnit_Framework_MockObject_MockObject
+     * @return MockObject
      */
     protected function setupTotalMock($itemMock, $isWeeeTaxable, $itemWeeeTaxDetails, $addressData)
     {
-        $totalMock = $this->createPartialMock(\Magento\Quote\Model\Quote\Address\Total::class, [
+        $totalMock = $this->createPartialMock(Total::class, [
                 '__wakeup',
                 'getWeeeCodeToItemMap',
                 'getExtraTaxableDetails',
@@ -125,24 +137,21 @@ protected function setupTotalMock($itemMock, $isWeeeTaxable, $itemWeeeTaxDetails
         if ($isWeeeTaxable) {
             $i = 1;
             $weeeTaxDetails = [];
-            foreach ($itemWeeeTaxDetails as $itemData) {
-                $code = 'weee' . $i++ . '-myWeeeCode';
+            foreach ($itemWeeeTaxDetails as $data) {
+                $code = 'weee' . ($i++) . '-myWeeeCode';
                 $map[$code] = $itemMock;
                 $weeeTaxDetails[] = [
                     CTC::KEY_TAX_DETAILS_TYPE => 'weee',
                     CTC::KEY_TAX_DETAILS_CODE => $code,
-                    CTC::KEY_TAX_DETAILS_PRICE_EXCL_TAX => $itemData['weee_tax_applied_amount'],
-                    CTC::KEY_TAX_DETAILS_BASE_PRICE_EXCL_TAX => $itemData['base_weee_tax_applied_amount'],
-                    CTC::KEY_TAX_DETAILS_PRICE_INCL_TAX => $itemData['weee_tax_applied_amount_incl_tax'],
-                    CTC::KEY_TAX_DETAILS_BASE_PRICE_INCL_TAX =>
-                        $itemData['base_weee_tax_applied_amount_incl_tax'],
-                    CTC::KEY_TAX_DETAILS_ROW_TOTAL => $itemData['weee_tax_applied_row_amount'],
-                    CTC::KEY_TAX_DETAILS_BASE_ROW_TOTAL => $itemData['base_weee_tax_applied_row_amnt'],
-                    CTC::KEY_TAX_DETAILS_ROW_TOTAL_INCL_TAX =>
-                        $itemData['weee_tax_applied_row_amount_incl_tax'],
-                    CTC::KEY_TAX_DETAILS_BASE_ROW_TOTAL_INCL_TAX =>
-                        $itemData['base_weee_tax_applied_row_amnt_incl_tax'],
-                    ];
+                    CTC::KEY_TAX_DETAILS_PRICE_EXCL_TAX => $data['weee_tax_applied_amount'],
+                    CTC::KEY_TAX_DETAILS_BASE_PRICE_EXCL_TAX => $data['base_weee_tax_applied_amount'],
+                    CTC::KEY_TAX_DETAILS_PRICE_INCL_TAX => $data['weee_tax_applied_amount_incl_tax'],
+                    CTC::KEY_TAX_DETAILS_BASE_PRICE_INCL_TAX => $data['base_weee_tax_applied_amount_incl_tax'],
+                    CTC::KEY_TAX_DETAILS_ROW_TOTAL => $data['weee_tax_applied_row_amount'],
+                    CTC::KEY_TAX_DETAILS_BASE_ROW_TOTAL => $data['base_weee_tax_applied_row_amnt'],
+                    CTC::KEY_TAX_DETAILS_ROW_TOTAL_INCL_TAX => $data['weee_tax_applied_row_amount_incl_tax'],
+                    CTC::KEY_TAX_DETAILS_BASE_ROW_TOTAL_INCL_TAX => $data['base_weee_tax_applied_row_amnt_incl_tax'],
+                ];
             }
             $extraDetails = [
                 'weee' => [
@@ -174,15 +183,15 @@ protected function setupTotalMock($itemMock, $isWeeeTaxable, $itemWeeeTaxDetails
 
     /**
      * Setup shipping assignment mock.
-     * @param \PHPUnit_Framework_MockObject_MockObject $addressMock
-     * @param \PHPUnit_Framework_MockObject_MockObject $itemMock
-     * @return \PHPUnit_Framework_MockObject_MockObject
+     * @param MockObject $addressMock
+     * @param MockObject $itemMock
+     * @return MockObject
      */
     protected function setupShippingAssignmentMock($addressMock, $itemMock)
     {
-        $shippingMock = $this->createMock(\Magento\Quote\Api\Data\ShippingInterface::class);
+        $shippingMock = $this->createMock(ShippingInterface::class);
         $shippingMock->expects($this->any())->method('getAddress')->willReturn($addressMock);
-        $shippingAssignmentMock = $this->createMock(\Magento\Quote\Api\Data\ShippingAssignmentInterface::class);
+        $shippingAssignmentMock = $this->createMock(ShippingAssignmentInterface::class);
         $itemMock = $itemMock ? [$itemMock] : [];
         $shippingAssignmentMock->expects($this->any())->method('getItems')->willReturn($itemMock);
         $shippingAssignmentMock->expects($this->any())->method('getShipping')->willReturn($shippingMock);
@@ -193,7 +202,7 @@ protected function setupShippingAssignmentMock($addressMock, $itemMock)
     /**
      * Verify that correct fields of item has been set
      *
-     * @param \PHPUnit_Framework_MockObject_MockObject|null $item
+     * @param MockObject|null $item
      * @param array $itemData
      */
     public function verifyItem($item, $itemData)
@@ -209,7 +218,7 @@ public function verifyItem($item, $itemData)
     /**
      * Verify that correct fields of address has been set
      *
-     * @param \PHPUnit_Framework_MockObject_MockObject|\Magento\Quote\Model\Quote\Address $address
+     * @param MockObject|Address $address
      * @param array $addressData
      */
     public function verifyTotals($address, $addressData)
@@ -224,16 +233,16 @@ public function verifyTotals($address, $addressData)
 
     public function testFetch()
     {
-        $serializerMock = $this->getMockBuilder(\Magento\Framework\Serialize\Serializer\Json::class)->getMock();
+        $serializerMock = $this->getMockBuilder(Json::class)->getMock();
         $weeeTotal = 17;
-        $totalMock = new \Magento\Quote\Model\Quote\Address\Total(
+        $totalMock = new Total(
             [],
             $serializerMock
         );
         $taxHelper = $this->setupTaxHelper([]);
         $weeeHelper = $this->setupWeeeHelper(['getTotalAmounts' => $weeeTotal]);
         $this->weeeCollector = $this->objectManagerHelper->getObject(
-            \Magento\Weee\Model\Total\Quote\WeeeTax::class,
+            WeeeTax::class,
             ['taxData' => $taxHelper, 'weeeData' => $weeeHelper]
         );
         $expectedResult = [
@@ -248,15 +257,15 @@ public function testFetch()
 
     public function testFetchWithZeroAmounts()
     {
-        $serializerMock = $this->getMockBuilder(\Magento\Framework\Serialize\Serializer\Json::class)->getMock();
-        $totalMock = new \Magento\Quote\Model\Quote\Address\Total(
+        $serializerMock = $this->getMockBuilder(Json::class)->getMock();
+        $totalMock = new Total(
             [],
             $serializerMock
         );
         $taxHelper = $this->setupTaxHelper([]);
         $weeeHelper = $this->setupWeeeHelper(['getTotalAmounts' => null]);
         $this->weeeCollector = $this->objectManagerHelper->getObject(
-            \Magento\Weee\Model\Total\Quote\WeeeTax::class,
+            WeeeTax::class,
             ['taxData' => $taxHelper, 'weeeData' => $weeeHelper]
         );
 
@@ -282,7 +291,7 @@ public function testCollect($taxConfig, $weeeConfig, $itemWeeeTaxDetails, $itemQ
             $itemMock = null;
         }
         $totalMock = $this->setupTotalMock($itemMock, $weeeConfig['isTaxable'], $itemWeeeTaxDetails, $addressData);
-        $addressMock = $this->createMock(\Magento\Quote\Model\Quote\Address::class);
+        $addressMock = $this->createMock(Address::class);
         $shippingAssignmentMock = $this->setupShippingAssignmentMock($addressMock, $itemMock);
 
         $taxHelper = $this->setupTaxHelper($taxConfig);
@@ -294,7 +303,7 @@ public function testCollect($taxConfig, $weeeConfig, $itemWeeeTaxDetails, $itemQ
         ];
 
         $this->weeeCollector = $this->objectManagerHelper->getObject(
-            \Magento\Weee\Model\Total\Quote\WeeeTax::class,
+            WeeeTax::class,
             $arguments
         );
 
diff --git a/app/code/Magento/Weee/Test/Unit/Model/Total/Quote/WeeeTest.php b/app/code/Magento/Weee/Test/Unit/Model/Total/Quote/WeeeTest.php
index 91cb2b5745bac..9c74ffae26993 100644
--- a/app/code/Magento/Weee/Test/Unit/Model/Total/Quote/WeeeTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Model/Total/Quote/WeeeTest.php
@@ -1,19 +1,35 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Model\Total\Quote;
 
+use Magento\Catalog\Model\Product;
+use Magento\Framework\DataObject;
+use Magento\Framework\Pricing\PriceCurrencyInterface;
+use Magento\Framework\Serialize\Serializer\Json;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Quote\Api\Data\ShippingAssignmentInterface;
+use Magento\Quote\Api\Data\ShippingInterface;
+use Magento\Quote\Model\Quote;
+use Magento\Quote\Model\Quote\Address;
+use Magento\Quote\Model\Quote\Address\Total;
+use Magento\Quote\Model\Quote\Item;
+use Magento\Store\Model\Store;
+use Magento\Tax\Helper\Data;
 use Magento\Tax\Model\Calculation;
+use Magento\Weee\Model\Total\Quote\Weee;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
-class WeeeTest extends \PHPUnit\Framework\TestCase
+class WeeeTest extends TestCase
 {
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject|\Magento\Framework\Pricing\PriceCurrencyInterface
+     * @var MockObject|PriceCurrencyInterface
      */
     protected $priceCurrency;
 
@@ -28,11 +44,11 @@ class WeeeTest extends \PHPUnit\Framework\TestCase
      * Setup tax helper with an array of methodName, returnValue
      *
      * @param array $taxConfig
-     * @return \PHPUnit_Framework_MockObject_MockObject|\Magento\Tax\Helper\Data
+     * @return MockObject|\Magento\Tax\Helper\Data
      */
     protected function setupTaxHelper($taxConfig)
     {
-        $taxHelper = $this->createMock(\Magento\Tax\Helper\Data::class);
+        $taxHelper = $this->createMock(Data::class);
 
         foreach ($taxConfig as $method => $value) {
             $taxHelper->expects($this->any())->method($method)->will($this->returnValue($value));
@@ -45,7 +61,7 @@ protected function setupTaxHelper($taxConfig)
      * Setup calculator to return tax rates
      *
      * @param array $taxRates
-     * @return \PHPUnit_Framework_MockObject_MockObject|\Magento\Tax\Model\Calculation
+     * @return MockObject|Calculation
      */
     protected function setupTaxCalculation($taxRates)
     {
@@ -53,12 +69,12 @@ protected function setupTaxCalculation($taxRates)
         $customerTaxRate = $taxRates['customer_tax_rate'];
 
         $taxCalculation = $this->createPartialMock(
-            \Magento\Tax\Model\Calculation::class,
+            Calculation::class,
             ['getRateOriginRequest', 'getRateRequest', 'getRate']
         );
 
-        $rateRequest = new \Magento\Framework\DataObject();
-        $defaultRateRequest = new \Magento\Framework\DataObject();
+        $rateRequest = new DataObject();
+        $defaultRateRequest = new DataObject();
 
         $taxCalculation->expects($this->any())->method('getRateRequest')->will($this->returnValue($rateRequest));
         $taxCalculation
@@ -78,11 +94,11 @@ protected function setupTaxCalculation($taxRates)
      * Setup weee helper with an array of methodName, returnValue
      *
      * @param array $weeeConfig
-     * @return \PHPUnit_Framework_MockObject_MockObject|\Magento\Weee\Helper\Data
+     * @return MockObject|\Magento\Weee\Helper\Data
      */
     protected function setupWeeeHelper($weeeConfig)
     {
-        $this->serializerMock = $this->getMockBuilder(\Magento\Framework\Serialize\Serializer\Json::class)->getMock();
+        $this->serializerMock = $this->getMockBuilder(Json::class)->getMock();
 
         $weeeHelper = $this->getMockBuilder(\Magento\Weee\Helper\Data::class)
             ->setConstructorArgs(['serializer'  => $this->serializerMock])
@@ -100,11 +116,11 @@ protected function setupWeeeHelper($weeeConfig)
      * Setup the basics of an item mock
      *
      * @param float $itemTotalQty
-     * @return \PHPUnit_Framework_MockObject_MockObject|\Magento\Quote\Model\Quote\Item
+     * @return MockObject|Item
      */
     protected function setupItemMockBasics($itemTotalQty)
     {
-        $itemMock = $this->createPartialMock(\Magento\Quote\Model\Quote\Item::class, [
+        $itemMock = $this->createPartialMock(Item::class, [
                 'getProduct',
                 'getQuote',
                 'getAddress',
@@ -116,7 +132,7 @@ protected function setupItemMockBasics($itemTotalQty)
                 '__wakeup',
             ]);
 
-        $productMock = $this->createMock(\Magento\Catalog\Model\Product::class);
+        $productMock = $this->createMock(Product::class);
         $itemMock->expects($this->any())->method('getProduct')->will($this->returnValue($productMock));
         $itemMock->expects($this->any())->method('getTotalQty')->will($this->returnValue($itemTotalQty));
 
@@ -127,7 +143,7 @@ protected function setupItemMockBasics($itemTotalQty)
      * Setup an item mock
      *
      * @param float $itemQty
-     * @return \PHPUnit_Framework_MockObject_MockObject|\Magento\Quote\Model\Quote\Item
+     * @return MockObject|Item
      */
     protected function setupItemMock($itemQty)
     {
@@ -146,7 +162,7 @@ protected function setupItemMock($itemQty)
      *
      * @param float $parentQty
      * @param float $itemQty
-     * @return \PHPUnit_Framework_MockObject_MockObject[]|\Magento\Quote\Model\Quote\Item[]
+     * @return MockObject[]|Item[]
      */
     protected function setupParentItemWithChildrenMock($parentQty, $itemQty)
     {
@@ -173,22 +189,22 @@ protected function setupParentItemWithChildrenMock($parentQty, $itemQty)
     /**
      * Setup address mock
      *
-     * @param \PHPUnit_Framework_MockObject_MockObject[]|\Magento\Quote\Model\Quote\Item[] $items
-     * @return \PHPUnit_Framework_MockObject_MockObject
+     * @param MockObject[]|Item[] $items
+     * @return MockObject
      */
     protected function setupAddressMock($items)
     {
-        $addressMock = $this->createPartialMock(\Magento\Quote\Model\Quote\Address::class, [
+        $addressMock = $this->createPartialMock(Address::class, [
                 '__wakeup',
                 'getAllItems',
                 'getQuote',
                 'getCustomAttributesCodes'
             ]);
 
-        $quoteMock = $this->createMock(\Magento\Quote\Model\Quote::class);
-        $storeMock = $this->createMock(\Magento\Store\Model\Store::class);
+        $quoteMock = $this->createMock(Quote::class);
+        $storeMock = $this->createMock(Store::class);
         $this->priceCurrency = $this->getMockBuilder(
-            \Magento\Framework\Pricing\PriceCurrencyInterface::class
+            PriceCurrencyInterface::class
         )->getMock();
         $this->priceCurrency->expects($this->any())->method('round')->willReturnArgument(0);
         $this->priceCurrency->expects($this->any())->method('convert')->willReturnArgument(0);
@@ -203,15 +219,15 @@ protected function setupAddressMock($items)
 
     /**
      * Setup shipping assignment mock.
-     * @param \PHPUnit_Framework_MockObject_MockObject $addressMock
-     * @param \PHPUnit_Framework_MockObject_MockObject $itemMock
-     * @return \PHPUnit_Framework_MockObject_MockObject
+     * @param MockObject $addressMock
+     * @param MockObject $itemMock
+     * @return MockObject
      */
     protected function setupShippingAssignmentMock($addressMock, $itemMock)
     {
-        $shippingMock = $this->createMock(\Magento\Quote\Api\Data\ShippingInterface::class);
+        $shippingMock = $this->createMock(ShippingInterface::class);
         $shippingMock->expects($this->any())->method('getAddress')->willReturn($addressMock);
-        $shippingAssignmentMock = $this->createMock(\Magento\Quote\Api\Data\ShippingAssignmentInterface::class);
+        $shippingAssignmentMock = $this->createMock(ShippingAssignmentInterface::class);
         $shippingAssignmentMock->expects($this->any())->method('getItems')->willReturn($itemMock);
         $shippingAssignmentMock->expects($this->any())->method('getShipping')->willReturn($shippingMock);
 
@@ -221,10 +237,10 @@ protected function setupShippingAssignmentMock($addressMock, $itemMock)
     /**
      * Verify that correct fields of item has been set
      *
-     * @param \PHPUnit_Framework_MockObject_MockObject|\Magento\Quote\Model\Quote\Item $item
+     * @param MockObject|Item $item
      * @param $itemData
      */
-    public function verifyItem(\Magento\Quote\Model\Quote\Item $item, $itemData)
+    public function verifyItem(Item $item, $itemData)
     {
         foreach ($itemData as $key => $value) {
             $this->assertEquals($value, $item->getData($key), 'item ' . $key . ' is incorrect');
@@ -234,7 +250,7 @@ public function verifyItem(\Magento\Quote\Model\Quote\Item $item, $itemData)
     /**
      * Verify that correct fields of address has been set
      *
-     * @param \PHPUnit_Framework_MockObject_MockObject|\Magento\Quote\Model\Quote\Address $address
+     * @param MockObject|Address $address
      * @param $addressData
      */
     public function verifyAddress($address, $addressData)
@@ -274,13 +290,13 @@ public function testCollect(
             $itemMock = $this->setupItemMock($itemQty);
             $items[] = $itemMock;
         }
-        $quoteMock = $this->createMock(\Magento\Quote\Model\Quote::class);
-        $storeMock = $this->createMock(\Magento\Store\Model\Store::class);
+        $quoteMock = $this->createMock(Quote::class);
+        $storeMock = $this->createMock(Store::class);
         $quoteMock->expects($this->any())->method('getStore')->will($this->returnValue($storeMock));
         $addressMock = $this->setupAddressMock($items);
-        $totalMock = new \Magento\Quote\Model\Quote\Address\Total(
+        $totalMock = new Total(
             [],
-            $this->getMockBuilder(\Magento\Framework\Serialize\Serializer\Json::class)->getMock()
+            $this->getMockBuilder(Json::class)->getMock()
         );
         $shippingAssignmentMock = $this->setupShippingAssignmentMock($addressMock, $items);
 
@@ -335,8 +351,8 @@ public function testCollect(
             'priceCurrency' => $this->priceCurrency
         ];
 
-        $helper = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
-        $this->weeeCollector = $helper->getObject(\Magento\Weee\Model\Total\Quote\Weee::class, $arguments);
+        $helper = new ObjectManager($this);
+        $this->weeeCollector = $helper->getObject(Weee::class, $arguments);
 
         $this->weeeCollector->collect($quoteMock, $shippingAssignmentMock, $totalMock);
 
@@ -371,7 +387,7 @@ public function collectDataProvider()
                 'isTaxable' => true,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
@@ -412,7 +428,7 @@ public function collectDataProvider()
                 'isTaxable' => true,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
@@ -453,7 +469,7 @@ public function collectDataProvider()
                 'isTaxable' => true,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
@@ -494,7 +510,7 @@ public function collectDataProvider()
                 'isTaxable' => false,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
@@ -537,7 +553,7 @@ public function collectDataProvider()
                 'isTaxable' => false,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
@@ -580,7 +596,7 @@ public function collectDataProvider()
                 'isTaxable' => true,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
@@ -621,7 +637,7 @@ public function collectDataProvider()
                 'isTaxable' => true,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
@@ -662,7 +678,7 @@ public function collectDataProvider()
                 'isTaxable' => false,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
@@ -705,7 +721,7 @@ public function collectDataProvider()
                 'isTaxable' => false,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
@@ -748,7 +764,7 @@ public function collectDataProvider()
                 'isTaxable' => false,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
@@ -791,7 +807,7 @@ public function collectDataProvider()
                 'isTaxable' => true,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
@@ -834,13 +850,13 @@ public function collectDataProvider()
                 'isTaxable' => false,
                 'getApplied' => [],
                 'getProductWeeeAttributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'Recycling Fee',
                             'amount' => 10,
                         ]
                     ),
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'name' => 'FPT Fee',
                             'amount' => 5,
diff --git a/app/code/Magento/Weee/Test/Unit/Model/WeeeConfigProviderTest.php b/app/code/Magento/Weee/Test/Unit/Model/WeeeConfigProviderTest.php
index d42d123f927c0..9d03cd7443b90 100644
--- a/app/code/Magento/Weee/Test/Unit/Model/WeeeConfigProviderTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Model/WeeeConfigProviderTest.php
@@ -1,47 +1,55 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Model;
 
-class WeeeConfigProviderTest extends \PHPUnit\Framework\TestCase
+use Magento\Store\Model\Store;
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\Weee\Helper\Data;
+use Magento\Weee\Model\Config;
+use Magento\Weee\Model\WeeeConfigProvider;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+
+class WeeeConfigProviderTest extends TestCase
 {
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $weeeHelperMock;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $weeeConfigMock;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $storeManagerMock;
 
     /**
-     * @var \PHPUnit_Framework_MockObject_MockObject
+     * @var MockObject
      */
     protected $storeMock;
 
     /**
-     * @var \Magento\Weee\Model\WeeeConfigProvider
+     * @var WeeeConfigProvider
      */
     protected $model;
 
-    protected function setUp()
+    protected function setUp(): void
     {
-        $this->weeeHelperMock = $this->createMock(\Magento\Weee\Helper\Data::class);
-        $this->weeeConfigMock = $this->createMock(\Magento\Weee\Model\Config::class);
-        $this->storeManagerMock = $this->createMock(\Magento\Store\Model\StoreManagerInterface::class);
-        $this->storeMock = $this->createMock(\Magento\Store\Model\Store::class);
+        $this->weeeHelperMock = $this->createMock(Data::class);
+        $this->weeeConfigMock = $this->createMock(Config::class);
+        $this->storeManagerMock = $this->createMock(StoreManagerInterface::class);
+        $this->storeMock = $this->createMock(Store::class);
 
         $this->storeManagerMock->expects($this->any())->method('getStore')->will($this->returnValue($this->storeMock));
 
-        $this->model = new \Magento\Weee\Model\WeeeConfigProvider(
+        $this->model = new WeeeConfigProvider(
             $this->weeeHelperMock,
             $this->storeManagerMock,
             $this->weeeConfigMock
diff --git a/app/code/Magento/Weee/Test/Unit/Observer/AddPaymentWeeeItemTest.php b/app/code/Magento/Weee/Test/Unit/Observer/AddPaymentWeeeItemTest.php
index dd0547354cfa4..d33474e05f86a 100644
--- a/app/code/Magento/Weee/Test/Unit/Observer/AddPaymentWeeeItemTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Observer/AddPaymentWeeeItemTest.php
@@ -17,12 +17,9 @@
 use Magento\Store\Model\StoreManagerInterface;
 use Magento\Weee\Helper\Data;
 use Magento\Weee\Observer\AddPaymentWeeeItem;
+use PHPUnit\Framework\MockObject\MockObject as MockObject;
 use PHPUnit\Framework\TestCase;
-use PHPUnit_Framework_MockObject_MockObject as MockObject;
 
-/**
- * Class AddPaymentWeeeItemTest
- */
 class AddPaymentWeeeItemTest extends TestCase
 {
     /**
@@ -45,7 +42,7 @@ class AddPaymentWeeeItemTest extends TestCase
     /**
      * Set Up
      */
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->weeeHelperMock = $this->createMock(Data::class);
         $this->storeManagerMock = $this->createMock(StoreManagerInterface::class);
diff --git a/app/code/Magento/Weee/Test/Unit/Observer/AfterAddressSaveTest.php b/app/code/Magento/Weee/Test/Unit/Observer/AfterAddressSaveTest.php
index 868d603f34b8c..7397728b30691 100644
--- a/app/code/Magento/Weee/Test/Unit/Observer/AfterAddressSaveTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Observer/AfterAddressSaveTest.php
@@ -1,18 +1,22 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Observer;
 
+use Magento\Customer\Model\Address;
+use Magento\Framework\Event\Observer;
+use Magento\Framework\Module\Manager;
 use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\PageCache\Model\Config;
 use Magento\Tax\Api\TaxAddressManagerInterface;
-use PHPUnit_Framework_MockObject_MockObject as MockObject;
+use Magento\Weee\Helper\Data;
+use Magento\Weee\Observer\AfterAddressSave;
+use PHPUnit\Framework\MockObject\MockObject as MockObject;
+use PHPUnit\Framework\TestCase;
 
-/**
- * After address save test.
- */
-class AfterAddressSaveTest extends \PHPUnit\Framework\TestCase
+class AfterAddressSaveTest extends TestCase
 {
     /**
      * @var ObjectManager
@@ -20,26 +24,26 @@ class AfterAddressSaveTest extends \PHPUnit\Framework\TestCase
     private $objectManager;
 
     /**
-     * @var \Magento\Framework\Event\Observer|\PHPUnit_Framework_MockObject_MockObject
+     * @var Observer|MockObject
      */
     private $observerMock;
 
     /**
      * Module manager
      *
-     * @var \Magento\Framework\Module\Manager|\PHPUnit_Framework_MockObject_MockObject
+     * @var Manager|MockObject
      */
     private $moduleManagerMock;
 
     /**
      * Cache config
      *
-     * @var \Magento\PageCache\Model\Config|\PHPUnit_Framework_MockObject_MockObject
+     * @var Config|MockObject
      */
     private $cacheConfigMock;
 
     /**
-     * @var \Magento\Weee\Helper\Data|\PHPUnit_Framework_MockObject_MockObject
+     * @var Data|MockObject
      */
     private $weeeHelperMock;
 
@@ -49,27 +53,27 @@ class AfterAddressSaveTest extends \PHPUnit\Framework\TestCase
     private $addressManagerMock;
 
     /**
-     * @var \Magento\Weee\Observer\AfterAddressSave
+     * @var AfterAddressSave
      */
     protected $session;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->objectManager = new ObjectManager($this);
-        $this->observerMock = $this->getMockBuilder(\Magento\Framework\Event\Observer::class)
+        $this->observerMock = $this->getMockBuilder(Observer::class)
             ->disableOriginalConstructor()
             ->setMethods(['getCustomerAddress'])
             ->getMock();
 
-        $this->moduleManagerMock = $this->getMockBuilder(\Magento\Framework\Module\Manager::class)
+        $this->moduleManagerMock = $this->getMockBuilder(Manager::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        $this->cacheConfigMock = $this->getMockBuilder(\Magento\PageCache\Model\Config::class)
+        $this->cacheConfigMock = $this->getMockBuilder(Config::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        $this->weeeHelperMock = $this->getMockBuilder(\Magento\Weee\Helper\Data::class)
+        $this->weeeHelperMock = $this->getMockBuilder(Data::class)
             ->disableOriginalConstructor()
             ->getMock();
 
@@ -79,7 +83,7 @@ protected function setUp()
             ->getMock();
 
         $this->session = $this->objectManager->getObject(
-            \Magento\Weee\Observer\AfterAddressSave::class,
+            AfterAddressSave::class,
             [
                 'weeeHelper' => $this->weeeHelperMock,
                 'moduleManager' => $this->moduleManagerMock,
@@ -117,8 +121,8 @@ public function testExecute(
             ->method('isEnabled')
             ->willReturn($isEnabledWeee);
 
-        /* @var \Magento\Customer\Model\Address|\PHPUnit_Framework_MockObject_MockObject $address */
-        $address = $this->getMockBuilder(\Magento\Customer\Model\Address::class)
+        /* @var \Magento\Customer\Model\Address|MockObject $address */
+        $address = $this->getMockBuilder(Address::class)
             ->disableOriginalConstructor()
             ->getMock();
 
diff --git a/app/code/Magento/Weee/Test/Unit/Observer/CustomerLoggedInTest.php b/app/code/Magento/Weee/Test/Unit/Observer/CustomerLoggedInTest.php
index af8c2e70a8ff6..59b3b3fe071f6 100644
--- a/app/code/Magento/Weee/Test/Unit/Observer/CustomerLoggedInTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Observer/CustomerLoggedInTest.php
@@ -1,39 +1,45 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Observer;
 
+use Magento\Customer\Api\Data\AddressInterface;
+use Magento\Customer\Model\Data\Customer;
+use Magento\Framework\Event\Observer;
+use Magento\Framework\Module\Manager;
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\PageCache\Model\Config;
 use Magento\Tax\Api\TaxAddressManagerInterface;
-use PHPUnit_Framework_MockObject_MockObject as MockObject;
+use Magento\Weee\Helper\Data;
+use Magento\Weee\Observer\CustomerLoggedIn;
+use PHPUnit\Framework\MockObject\MockObject as MockObject;
+use PHPUnit\Framework\TestCase;
 
-/**
- * Customer logged in test
- */
-class CustomerLoggedInTest extends \PHPUnit\Framework\TestCase
+class CustomerLoggedInTest extends TestCase
 {
     /**
-     * @var \Magento\Framework\Event\Observer
+     * @var Observer
      */
     protected $observerMock;
 
     /**
      * Module manager
      *
-     * @var \Magento\Framework\Module\Manager
+     * @var Manager
      */
     private $moduleManagerMock;
 
     /**
      * Cache config
      *
-     * @var \Magento\PageCache\Model\Config
+     * @var Config
      */
     private $cacheConfigMock;
 
     /**
-     * @var \Magento\Weee\Helper\Data
+     * @var Data
      */
     protected $weeeHelperMock;
 
@@ -43,14 +49,14 @@ class CustomerLoggedInTest extends \PHPUnit\Framework\TestCase
     private $addressManagerMock;
 
     /**
-     * @var \Magento\Weee\Observer\CustomerLoggedIn
+     * @var CustomerLoggedIn
      */
     protected $session;
 
-    protected function setUp()
+    protected function setUp(): void
     {
-        $objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
-        $this->observerMock = $this->getMockBuilder(\Magento\Framework\Event\Observer::class)
+        $objectManager = new ObjectManager($this);
+        $this->observerMock = $this->getMockBuilder(Observer::class)
             ->disableOriginalConstructor()
             ->setMethods(
                 [
@@ -59,15 +65,15 @@ protected function setUp()
             )
             ->getMock();
 
-        $this->moduleManagerMock = $this->getMockBuilder(\Magento\Framework\Module\Manager::class)
+        $this->moduleManagerMock = $this->getMockBuilder(Manager::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        $this->cacheConfigMock = $this->getMockBuilder(\Magento\PageCache\Model\Config::class)
+        $this->cacheConfigMock = $this->getMockBuilder(Config::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        $this->weeeHelperMock = $this->getMockBuilder(\Magento\Weee\Helper\Data::class)
+        $this->weeeHelperMock = $this->getMockBuilder(Data::class)
             ->disableOriginalConstructor()
             ->getMock();
 
@@ -77,7 +83,7 @@ protected function setUp()
             ->getMock();
 
         $this->session = $objectManager->getObject(
-            \Magento\Weee\Observer\CustomerLoggedIn::class,
+            CustomerLoggedIn::class,
             [
                 'weeeHelper' => $this->weeeHelperMock,
                 'moduleManager' => $this->moduleManagerMock,
@@ -105,12 +111,12 @@ public function testExecute()
             ->method('isEnabled')
             ->willReturn(true);
 
-        $customerMock = $this->getMockBuilder(\Magento\Customer\Model\Data\Customer::class)
+        $customerMock = $this->getMockBuilder(Customer::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        /* @var \Magento\Customer\Api\Data\AddressInterface|\PHPUnit_Framework_MockObject_MockObject $address */
-        $address = $this->getMockBuilder(\Magento\Customer\Api\Data\AddressInterface::class)
+        /* @var \Magento\Customer\Api\Data\AddressInterface|MockObject $address */
+        $address = $this->getMockBuilder(AddressInterface::class)
             ->disableOriginalConstructor()
             ->getMock();
 
diff --git a/app/code/Magento/Weee/Test/Unit/Observer/GetPriceConfigurationObserverTest.php b/app/code/Magento/Weee/Test/Unit/Observer/GetPriceConfigurationObserverTest.php
index 848f315f0cbd9..927e8d0b07bc7 100644
--- a/app/code/Magento/Weee/Test/Unit/Observer/GetPriceConfigurationObserverTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Observer/GetPriceConfigurationObserverTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -6,9 +6,17 @@
 
 namespace Magento\Weee\Test\Unit\Observer;
 
+use Magento\Bundle\Model\Product\Type;
+use Magento\Catalog\Model\Product\Type\Simple;
+use Magento\Framework\DataObject;
+use Magento\Framework\Event\Observer;
+use Magento\Framework\Registry;
 use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Weee\Helper\Data;
+use Magento\Weee\Observer\GetPriceConfigurationObserver;
+use PHPUnit\Framework\TestCase;
 
-class GetPriceConfigurationObserverTest extends \PHPUnit\Framework\TestCase
+class GetPriceConfigurationObserverTest extends TestCase
 {
     /**
      * Tests the methods that rely on the ScopeConfigInterface object to provide their return values
@@ -19,41 +27,41 @@ class GetPriceConfigurationObserverTest extends \PHPUnit\Framework\TestCase
      */
     public function testGetPriceConfiguration($hasWeeeAttributes, $testArray, $expectedArray)
     {
-        $configObj = new \Magento\Framework\DataObject(
+        $configObj = new DataObject(
             [
                 'config' => $testArray,
             ]
         );
 
-        $weeeObject1 = new \Magento\Framework\DataObject(
+        $weeeObject1 = new DataObject(
             [
                 'code' => 'fpt1',
                 'amount' => '15.0000',
             ]
         );
 
-        $weeeObject2 = new \Magento\Framework\DataObject(
+        $weeeObject2 = new DataObject(
             [
                 'code' => 'fpt2',
                 'amount' => '16.0000',
             ]
         );
 
-        $weeeHelper=$this->createMock(\Magento\Weee\Helper\Data::class);
+        $weeeHelper=$this->createMock(Data::class);
         $weeeHelper->expects($this->any())
             ->method('isEnabled')
             ->will($this->returnValue(true));
 
-        $observerObject=$this->createMock(\Magento\Framework\Event\Observer::class);
+        $observerObject=$this->createMock(Observer::class);
         $observerObject->expects($this->any())
             ->method('getData')
             ->with('configObj')
             ->will($this->returnValue($configObj));
 
-        $productInstance=$this->createMock(\Magento\Catalog\Model\Product\Type\Simple::class);
+        $productInstance=$this->createMock(Simple::class);
 
         $product = $this->createPartialMock(
-            \Magento\Bundle\Model\Product\Type::class,
+            Type::class,
             ['getTypeInstance', 'getTypeId', 'getStoreId']
         );
         $product->expects($this->any())
@@ -66,7 +74,7 @@ public function testGetPriceConfiguration($hasWeeeAttributes, $testArray, $expec
             ->method('getStoreId')
             ->will($this->returnValue(null));
 
-        $registry=$this->createMock(\Magento\Framework\Registry::class);
+        $registry=$this->createMock(Registry::class);
         $registry->expects($this->any())
             ->method('registry')
             ->with('current_product')
@@ -89,9 +97,9 @@ public function testGetPriceConfiguration($hasWeeeAttributes, $testArray, $expec
         }
 
         $objectManager = new ObjectManager($this);
-        /** @var \Magento\Weee\Observer\GetPriceConfigurationObserver $weeeObserverObject */
+        /** @var GetPriceConfigurationObserver $weeeObserverObject */
         $weeeObserverObject = $objectManager->getObject(
-            \Magento\Weee\Observer\GetPriceConfigurationObserver::class,
+            GetPriceConfigurationObserver::class,
             [
                 'weeeData' => $weeeHelper,
                 'registry' => $registry,
diff --git a/app/code/Magento/Weee/Test/Unit/Observer/SetWeeeRendererInFormObserverTest.php b/app/code/Magento/Weee/Test/Unit/Observer/SetWeeeRendererInFormObserverTest.php
index 188b42cb37906..b9d2098416592 100644
--- a/app/code/Magento/Weee/Test/Unit/Observer/SetWeeeRendererInFormObserverTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Observer/SetWeeeRendererInFormObserverTest.php
@@ -13,12 +13,9 @@
 use Magento\Framework\View\LayoutInterface;
 use Magento\Weee\Model\Tax;
 use Magento\Weee\Observer\SetWeeeRendererInFormObserver;
+use PHPUnit\Framework\MockObject\MockObject as MockObject;
 use PHPUnit\Framework\TestCase;
-use PHPUnit_Framework_MockObject_MockObject as MockObject;
 
-/**
- * Class AddPaymentWeeeItemTest
- */
 class SetWeeeRendererInFormObserverTest extends TestCase
 {
     /**
@@ -41,7 +38,7 @@ class SetWeeeRendererInFormObserverTest extends TestCase
     /**
      * Set Up
      */
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->layoutMock = $this->createMock(LayoutInterface::class);
         $this->taxModelMock = $this->createMock(Tax::class);
diff --git a/app/code/Magento/Weee/Test/Unit/Observer/UpdateProductOptionsObserverTest.php b/app/code/Magento/Weee/Test/Unit/Observer/UpdateProductOptionsObserverTest.php
index a3fa2ce474e0d..b997cf7c295f0 100644
--- a/app/code/Magento/Weee/Test/Unit/Observer/UpdateProductOptionsObserverTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Observer/UpdateProductOptionsObserverTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -6,11 +6,18 @@
 
 namespace Magento\Weee\Test\Unit\Observer;
 
+use Magento\Bundle\Model\Product\Type;
+use Magento\Framework\DataObject;
+use Magento\Framework\Event\Observer;
+use Magento\Framework\Registry;
 use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
-use Magento\Weee\Model\Tax as WeeeDisplayConfig;
 use Magento\Tax\Model\Config as TaxConfig;
+use Magento\Weee\Helper\Data;
+use Magento\Weee\Model\Tax as WeeeDisplayConfig;
+use Magento\Weee\Observer\UpdateProductOptionsObserver;
+use PHPUnit\Framework\TestCase;
 
-class UpdateProductOptionsObserverTest extends \PHPUnit\Framework\TestCase
+class UpdateProductOptionsObserverTest extends TestCase
 {
     /**
      * Tests the methods that rely on the ScopeConfigInterface object to provide their return values
@@ -25,27 +32,27 @@ class UpdateProductOptionsObserverTest extends \PHPUnit\Framework\TestCase
      */
     public function testUpdateProductOptions($initialArray, $weeeEnabled, $weeeDisplay, $priceDisplay, $expectedArray)
     {
-        $configObj = new \Magento\Framework\DataObject(
+        $configObj = new DataObject(
             [
                 'additional_options' => $initialArray,
             ]
         );
 
-        $weeeObject1 = new \Magento\Framework\DataObject(
+        $weeeObject1 = new DataObject(
             [
                 'code' => 'fpt1',
                 'amount' => '15.0000',
             ]
         );
 
-        $weeeObject2 = new \Magento\Framework\DataObject(
+        $weeeObject2 = new DataObject(
             [
                 'code' => 'fpt2',
                 'amount' => '7.0000',
             ]
         );
 
-        $weeeHelper=$this->createMock(\Magento\Weee\Helper\Data::class);
+        $weeeHelper=$this->createMock(Data::class);
         $weeeHelper->expects($this->any())
             ->method('isEnabled')
             ->will($this->returnValue($weeeEnabled));
@@ -70,17 +77,17 @@ public function testUpdateProductOptions($initialArray, $weeeEnabled, $weeeDispl
             ->method('priceIncludesTax')
             ->will($this->returnValue(true));
 
-        $responseObject=$this->createPartialMock(\Magento\Framework\Event\Observer::class, ['getResponseObject']);
+        $responseObject=$this->createPartialMock(Observer::class, ['getResponseObject']);
         $responseObject->expects($this->any())
             ->method('getResponseObject')
             ->will($this->returnValue($configObj));
 
-        $observerObject=$this->createPartialMock(\Magento\Framework\Event\Observer::class, ['getEvent']);
+        $observerObject=$this->createPartialMock(Observer::class, ['getEvent']);
         $observerObject->expects($this->any())
             ->method('getEvent')
             ->will($this->returnValue($responseObject));
 
-        $product = $this->createPartialMock(\Magento\Bundle\Model\Product\Type::class, ['getTypeId', 'getStoreId']);
+        $product = $this->createPartialMock(Type::class, ['getTypeId', 'getStoreId']);
         $product->expects($this->any())
             ->method('getStoreId')
             ->will($this->returnValue(1));
@@ -88,16 +95,16 @@ public function testUpdateProductOptions($initialArray, $weeeEnabled, $weeeDispl
             ->method('getTypeId')
             ->will($this->returnValue('bundle'));
 
-        $registry=$this->createMock(\Magento\Framework\Registry::class);
+        $registry=$this->createMock(Registry::class);
         $registry->expects($this->any())
             ->method('registry')
             ->with('current_product')
             ->will($this->returnValue($product));
 
         $objectManager = new ObjectManager($this);
-        /** @var \Magento\Weee\Observer\UpdateProductOptionsObserver $weeeObserverObject */
+        /** @var UpdateProductOptionsObserver $weeeObserverObject */
         $weeeObserverObject = $objectManager->getObject(
-            \Magento\Weee\Observer\UpdateProductOptionsObserver::class,
+            UpdateProductOptionsObserver::class,
             [
                 'weeeData' => $weeeHelper,
                 'taxData' => $taxHelper,
diff --git a/app/code/Magento/Weee/Test/Unit/Plugin/Catalog/Controller/Adminhtml/Product/Initialization/Helper/ProcessTaxAttributeTest.php b/app/code/Magento/Weee/Test/Unit/Plugin/Catalog/Controller/Adminhtml/Product/Initialization/Helper/ProcessTaxAttributeTest.php
index 2c88d3e0f0251..f809418853102 100644
--- a/app/code/Magento/Weee/Test/Unit/Plugin/Catalog/Controller/Adminhtml/Product/Initialization/Helper/ProcessTaxAttributeTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Plugin/Catalog/Controller/Adminhtml/Product/Initialization/Helper/ProcessTaxAttributeTest.php
@@ -61,7 +61,7 @@ class ProcessTaxAttributeTest extends TestCase
     /**
      * Prepare environment for test
      */
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->subjectMock = $this->createMock(Helper::class);
         $this->resultMock = $this->createMock(Product::class);
diff --git a/app/code/Magento/Weee/Test/Unit/Plugin/Ui/DataProvider/WeeeSettingsTest.php b/app/code/Magento/Weee/Test/Unit/Plugin/Ui/DataProvider/WeeeSettingsTest.php
index 0ac9c55313538..02e6b60616c99 100644
--- a/app/code/Magento/Weee/Test/Unit/Plugin/Ui/DataProvider/WeeeSettingsTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Plugin/Ui/DataProvider/WeeeSettingsTest.php
@@ -41,7 +41,7 @@ class WeeeSettingsTest extends TestCase
     /**
      * Prepare environment for test
      */
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->configMock = $this->createMock(Config::class);
         $this->subjectMock = $this->createMock(DataProvider::class);
diff --git a/app/code/Magento/Weee/Test/Unit/Pricing/AdjustmentTest.php b/app/code/Magento/Weee/Test/Unit/Pricing/AdjustmentTest.php
index a0d0b6486c7d9..2cf986dd08cc5 100644
--- a/app/code/Magento/Weee/Test/Unit/Pricing/AdjustmentTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Pricing/AdjustmentTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -6,12 +6,15 @@
 
 namespace Magento\Weee\Test\Unit\Pricing;
 
-use \Magento\Weee\Pricing\Adjustment;
-
+use Magento\Framework\Pricing\PriceCurrencyInterface;
 use Magento\Framework\Pricing\SaleableInterface;
-use Magento\Weee\Helper\Data as WeeeHelper;
+use Magento\Weee\Model\Tax;
+use Magento\Weee\Pricing\Adjustment;
+use PHPUnit\Framework\MockObject\MockObject;
+
+use PHPUnit\Framework\TestCase;
 
-class AdjustmentTest extends \PHPUnit\Framework\TestCase
+class AdjustmentTest extends TestCase
 {
     /**
      * @var Adjustment
@@ -19,12 +22,12 @@ class AdjustmentTest extends \PHPUnit\Framework\TestCase
     protected $adjustment;
 
     /**
-     * @var \Magento\Weee\Helper\Data | \PHPUnit_Framework_MockObject_MockObject
+     * @var \Magento\Weee\Helper\Data|MockObject
      */
     protected $weeeHelper;
 
     /**
-     * @var \Magento\Framework\Pricing\PriceCurrencyInterface|\PHPUnit_Framework_MockObject_MockObject
+     * @var PriceCurrencyInterface|MockObject
      */
     protected $priceCurrencyMock;
 
@@ -33,10 +36,10 @@ class AdjustmentTest extends \PHPUnit\Framework\TestCase
      */
     protected $sortOrder = 5;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->weeeHelper = $this->createMock(\Magento\Weee\Helper\Data::class);
-        $this->priceCurrencyMock = $this->createMock(\Magento\Framework\Pricing\PriceCurrencyInterface::class);
+        $this->priceCurrencyMock = $this->createMock(PriceCurrencyInterface::class);
         $this->priceCurrencyMock->expects($this->any())
             ->method('convertAndRound')
             ->will(
@@ -75,9 +78,9 @@ public function testIsIncludedInBasePrice()
     public function testIsIncludedInDisplayPrice($expectedResult)
     {
         $displayTypes = [
-            \Magento\Weee\Model\Tax::DISPLAY_INCL,
-            \Magento\Weee\Model\Tax::DISPLAY_INCL_DESCR,
-            \Magento\Weee\Model\Tax::DISPLAY_EXCL_DESCR_INCL,
+            Tax::DISPLAY_INCL,
+            Tax::DISPLAY_INCL_DESCR,
+            Tax::DISPLAY_EXCL_DESCR_INCL,
         ];
         $this->weeeHelper->expects($this->any())
             ->method('typeOfDisplay')
@@ -103,7 +106,7 @@ public function isIncludedInDisplayPriceDataProvider()
      */
     public function testApplyAdjustment($amount, $amountOld, $expectedResult)
     {
-        $object = $this->getMockForAbstractClass(\Magento\Framework\Pricing\SaleableInterface::class);
+        $object = $this->getMockForAbstractClass(SaleableInterface::class);
 
         $this->weeeHelper->expects($this->any())
             ->method('getAmountExclTax')
diff --git a/app/code/Magento/Weee/Test/Unit/Pricing/Render/AdjustmentTest.php b/app/code/Magento/Weee/Test/Unit/Pricing/Render/AdjustmentTest.php
index 2d18793de209b..251aacd5ff929 100644
--- a/app/code/Magento/Weee/Test/Unit/Pricing/Render/AdjustmentTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Pricing/Render/AdjustmentTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -6,17 +6,28 @@
 
 namespace Magento\Weee\Test\Unit\Pricing\Render;
 
+use Magento\Catalog\Model\Product;
+use Magento\Directory\Model\PriceCurrency;
+use Magento\Framework\App\Config\ScopeConfigInterface;
+use Magento\Framework\DataObject;
+use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\Pricing\Amount\Base;
+use Magento\Framework\Pricing\PriceCurrencyInterface;
+use Magento\Framework\Pricing\Render\Amount;
+use Magento\Framework\View\Element\Template\Context;
+use Magento\Weee\Helper\Data;
+use Magento\Weee\Model\Tax;
+use Magento\Weee\Pricing\Adjustment as PricingAdjustment;
 use Magento\Weee\Pricing\Render\Adjustment;
+use PHPUnit\Framework\TestCase;
 
 /**
- * Class AdjustmentTest for testing Adjustment class
- *
  * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
-class AdjustmentTest extends \PHPUnit\Framework\TestCase
+class AdjustmentTest extends TestCase
 {
     /**
-     * @var \Magento\Weee\Pricing\Render\Adjustment
+     * @var Adjustment
      */
     protected $model;
 
@@ -35,21 +46,21 @@ class AdjustmentTest extends \PHPUnit\Framework\TestCase
     /**
      * Price currency model mock
      *
-     * @var \Magento\Directory\Model\PriceCurrency
+     * @var PriceCurrency
      */
     protected $priceCurrencyMock;
 
     /**
      * Set up mocks for tested class
      */
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->contextMock = $this->createPartialMock(
-            \Magento\Framework\View\Element\Template\Context::class,
+            Context::class,
             ['getStoreConfig', 'getEventManager', 'getScopeConfig']
         );
         $this->priceCurrencyMock = $this->getMockForAbstractClass(
-            \Magento\Framework\Pricing\PriceCurrencyInterface::class,
+            PriceCurrencyInterface::class,
             [],
             '',
             true,
@@ -57,23 +68,16 @@ protected function setUp()
             true,
             []
         );
-        $this->weeeHelperMock = $this->createMock(\Magento\Weee\Helper\Data::class);
-        $eventManagerMock = $this->getMockBuilder(\Magento\Framework\Event\ManagerInterface::class)
+        $this->weeeHelperMock = $this->createMock(Data::class);
+        $eventManagerMock = $this->getMockBuilder(ManagerInterface::class)
             ->disableOriginalConstructor()
             ->getMockForAbstractClass();
 
-        $storeConfigMock = $this->getMockBuilder(\Magento\Store\Model\Store\Config::class)
-            ->disableOriginalConstructor()
-            ->getMock();
-
-        $scopeConfigMock = $this->getMockForAbstractClass(\Magento\Framework\App\Config\ScopeConfigInterface::class);
+        $scopeConfigMock = $this->getMockForAbstractClass(ScopeConfigInterface::class);
 
         $this->contextMock->expects($this->any())
             ->method('getEventManager')
             ->will($this->returnValue($eventManagerMock));
-        $this->contextMock->expects($this->any())
-            ->method('getStoreConfig')
-            ->will($this->returnValue($storeConfigMock));
         $this->contextMock->expects($this->any())
             ->method('getScopeConfig')
             ->will($this->returnValue($scopeConfigMock));
@@ -90,7 +94,7 @@ protected function setUp()
      */
     public function testGetAdjustmentCode()
     {
-        $this->assertEquals(\Magento\Weee\Pricing\Adjustment::ADJUSTMENT_CODE, $this->model->getAdjustmentCode());
+        $this->assertEquals(PricingAdjustment::ADJUSTMENT_CODE, $this->model->getAdjustmentCode());
     }
 
     /**
@@ -106,8 +110,8 @@ public function testGetFinalAmount()
         $displayValue = 10;
         $expectedValue = "$10.00";
         $typeOfDisplay = 1; //Just to set it to not false
-        /** @var \Magento\Framework\Pricing\Render\Amount $amountRender */
-        $amountRender = $this->getMockBuilder(\Magento\Framework\Pricing\Render\Amount::class)
+        /** @var Amount $amountRender */
+        $amountRender = $this->getMockBuilder(Amount::class)
             ->disableOriginalConstructor()
             ->setMethods(['getSaleableItem', 'getDisplayValue', 'getAmount'])
             ->getMock();
@@ -115,8 +119,8 @@ public function testGetFinalAmount()
             ->method('getDisplayValue')
             ->will($this->returnValue($displayValue));
         $this->weeeHelperMock->expects($this->any())->method('typeOfDisplay')->will($this->returnValue($typeOfDisplay));
-        /** @var \Magento\Framework\Pricing\Amount\Base $baseAmount */
-        $baseAmount = $this->getMockBuilder(\Magento\Framework\Pricing\Amount\Base::class)
+        /** @var Base $baseAmount */
+        $baseAmount = $this->getMockBuilder(Base::class)
             ->disableOriginalConstructor()
             ->setMethods(['getValue'])
             ->getMock();
@@ -137,18 +141,18 @@ public function testGetFinalAmount()
      */
     public function testShowInclDescr($typeOfDisplay, $amount, $expectedResult)
     {
-        /** @var \Magento\Framework\Pricing\Render\Amount $amountRender */
-        $amountRender = $this->getMockBuilder(\Magento\Framework\Pricing\Render\Amount::class)
+        /** @var Amount $amountRender */
+        $amountRender = $this->getMockBuilder(Amount::class)
             ->disableOriginalConstructor()
             ->setMethods(['getSaleableItem', 'getDisplayValue', 'getAmount'])
             ->getMock();
-        /** @var \Magento\Catalog\Model\Product $saleable */
-        $saleable = $this->getMockBuilder(\Magento\Catalog\Model\Product::class)
+        /** @var Product $saleable */
+        $saleable = $this->getMockBuilder(Product::class)
             ->disableOriginalConstructor()
             ->setMethods(['__wakeup'])
             ->getMock();
-        /** @var \Magento\Framework\Pricing\Amount\Base $baseAmount */
-        $baseAmount = $this->getMockBuilder(\Magento\Framework\Pricing\Amount\Base::class)
+        /** @var Base $baseAmount */
+        $baseAmount = $this->getMockBuilder(Base::class)
             ->disableOriginalConstructor()
             ->setMethods(['getValue'])
             ->getMock();
@@ -187,15 +191,15 @@ public function testShowInclDescr($typeOfDisplay, $amount, $expectedResult)
     public function showInclDescrDataProvider()
     {
         return [
-            [\Magento\Weee\Model\Tax::DISPLAY_INCL, 1.23, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_INCL_DESCR, 1.23, true],
-            [\Magento\Weee\Model\Tax::DISPLAY_EXCL_DESCR_INCL, 1.23, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_EXCL, 1.23, false],
+            [Tax::DISPLAY_INCL, 1.23, false],
+            [Tax::DISPLAY_INCL_DESCR, 1.23, true],
+            [Tax::DISPLAY_EXCL_DESCR_INCL, 1.23, false],
+            [Tax::DISPLAY_EXCL, 1.23, false],
             [4, 1.23, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_INCL, 0, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_INCL_DESCR, 0, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_EXCL_DESCR_INCL, 0, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_EXCL, 0, false],
+            [Tax::DISPLAY_INCL, 0, false],
+            [Tax::DISPLAY_INCL_DESCR, 0, false],
+            [Tax::DISPLAY_EXCL_DESCR_INCL, 0, false],
+            [Tax::DISPLAY_EXCL, 0, false],
             [4, 0, false],
         ];
     }
@@ -210,18 +214,18 @@ public function showInclDescrDataProvider()
      */
     public function testShowExclDescrIncl($typeOfDisplay, $amount, $expectedResult)
     {
-        /** @var \Magento\Framework\Pricing\Render\Amount $amountRender */
-        $amountRender = $this->getMockBuilder(\Magento\Framework\Pricing\Render\Amount::class)
+        /** @var Amount $amountRender */
+        $amountRender = $this->getMockBuilder(Amount::class)
             ->disableOriginalConstructor()
             ->setMethods(['getSaleableItem', 'getDisplayValue', 'getAmount'])
             ->getMock();
-        /** @var \Magento\Catalog\Model\Product $saleable */
-        $saleable = $this->getMockBuilder(\Magento\Catalog\Model\Product::class)
+        /** @var Product $saleable */
+        $saleable = $this->getMockBuilder(Product::class)
             ->disableOriginalConstructor()
             ->setMethods(['__wakeup'])
             ->getMock();
-        /** @var \Magento\Framework\Pricing\Amount\Base $baseAmount */
-        $baseAmount = $this->getMockBuilder(\Magento\Framework\Pricing\Amount\Base::class)
+        /** @var Base $baseAmount */
+        $baseAmount = $this->getMockBuilder(Base::class)
             ->disableOriginalConstructor()
             ->setMethods(['getValue'])
             ->getMock();
@@ -258,15 +262,15 @@ public function testShowExclDescrIncl($typeOfDisplay, $amount, $expectedResult)
     public function showExclDescrInclDataProvider()
     {
         return [
-            [\Magento\Weee\Model\Tax::DISPLAY_INCL, 1.23, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_INCL_DESCR, 1.23, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_EXCL_DESCR_INCL, 1.23, true],
-            [\Magento\Weee\Model\Tax::DISPLAY_EXCL, 1.23, false],
+            [Tax::DISPLAY_INCL, 1.23, false],
+            [Tax::DISPLAY_INCL_DESCR, 1.23, false],
+            [Tax::DISPLAY_EXCL_DESCR_INCL, 1.23, true],
+            [Tax::DISPLAY_EXCL, 1.23, false],
             [4, 1.23, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_INCL, 0, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_INCL_DESCR, 0, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_EXCL_DESCR_INCL, 0, false],
-            [\Magento\Weee\Model\Tax::DISPLAY_EXCL, 0, false],
+            [Tax::DISPLAY_INCL, 0, false],
+            [Tax::DISPLAY_INCL_DESCR, 0, false],
+            [Tax::DISPLAY_EXCL_DESCR_INCL, 0, false],
+            [Tax::DISPLAY_EXCL, 0, false],
             [4, 0, false],
         ];
     }
@@ -281,18 +285,18 @@ public function showExclDescrInclDataProvider()
      */
     public function testGetWeeeTaxAttributes($typeOfDisplay, $attributes, $expectedResult)
     {
-        /** @var \Magento\Framework\Pricing\Render\Amount $amountRender */
-        $amountRender = $this->getMockBuilder(\Magento\Framework\Pricing\Render\Amount::class)
+        /** @var Amount $amountRender */
+        $amountRender = $this->getMockBuilder(Amount::class)
             ->disableOriginalConstructor()
             ->setMethods(['getSaleableItem', 'getDisplayValue', 'getAmount'])
             ->getMock();
-        /** @var \Magento\Catalog\Model\Product $saleable */
-        $saleable = $this->getMockBuilder(\Magento\Catalog\Model\Product::class)
+        /** @var Product $saleable */
+        $saleable = $this->getMockBuilder(Product::class)
             ->disableOriginalConstructor()
             ->setMethods(['__wakeup'])
             ->getMock();
-        /** @var \Magento\Framework\Pricing\Amount\Base $baseAmount */
-        $baseAmount = $this->getMockBuilder(\Magento\Framework\Pricing\Amount\Base::class)
+        /** @var Base $baseAmount */
+        $baseAmount = $this->getMockBuilder(Base::class)
             ->disableOriginalConstructor()
             ->setMethods(['getValue'])
             ->getMock();
@@ -326,10 +330,10 @@ public function testGetWeeeTaxAttributes($typeOfDisplay, $attributes, $expectedR
     public function getWeeeTaxAttributesDataProvider()
     {
         return [
-            [\Magento\Weee\Model\Tax::DISPLAY_INCL, [1, 2, 3], []],
-            [\Magento\Weee\Model\Tax::DISPLAY_INCL_DESCR, [1, 2, 3], [1, 2, 3]],
-            [\Magento\Weee\Model\Tax::DISPLAY_EXCL_DESCR_INCL, [1, 2, 3], [1, 2, 3]],
-            [\Magento\Weee\Model\Tax::DISPLAY_EXCL, [1, 2, 3], []],
+            [Tax::DISPLAY_INCL, [1, 2, 3], []],
+            [Tax::DISPLAY_INCL_DESCR, [1, 2, 3], [1, 2, 3]],
+            [Tax::DISPLAY_EXCL_DESCR_INCL, [1, 2, 3], [1, 2, 3]],
+            [Tax::DISPLAY_EXCL, [1, 2, 3], []],
             [4, [1, 2, 3], []],
         ];
     }
@@ -337,7 +341,7 @@ public function getWeeeTaxAttributesDataProvider()
     /**
      * Test for method renderWeeeTaxAttribute
      *
-     * @param \Magento\Framework\DataObject $attribute
+     * @param DataObject $attribute
      * @param string $expectedResult
      * @dataProvider renderWeeeTaxAttributeAmountDataProvider
      */
@@ -357,15 +361,15 @@ public function testRenderWeeeTaxAttributeAmount($attribute, $expectedResult)
     public function renderWeeeTaxAttributeAmountDataProvider()
     {
         return [
-            [new \Magento\Framework\DataObject(['amount' => 51]), 51],
-            [new \Magento\Framework\DataObject(['amount' => false]), false],
+            [new DataObject(['amount' => 51]), 51],
+            [new DataObject(['amount' => false]), false],
         ];
     }
 
     /**
      * Test for method renderWeeeTaxAttributeName
      *
-     * @param \Magento\Framework\DataObject $attribute
+     * @param DataObject $attribute
      * @param string $expectedResult
      * @dataProvider renderWeeeTaxAttributeNameDataProvider
      */
@@ -385,15 +389,15 @@ public function testRenderWeeeTaxAttributeName($attribute, $expectedResult)
     public function renderWeeeTaxAttributeNameDataProvider()
     {
         return [
-            [new \Magento\Framework\DataObject(['name' => 51]), 51],
-            [new \Magento\Framework\DataObject(['name' => false]), false],
+            [new DataObject(['name' => 51]), 51],
+            [new DataObject(['name' => false]), false],
         ];
     }
 
     /**
      * Test for method renderWeeeTaxAttributeWithTax
      *
-     * @param \Magento\Framework\DataObject $attribute
+     * @param DataObject $attribute
      * @param string $expectedResult
      * @dataProvider renderWeeeTaxAttributeAmountWithTaxDataProvider
      */
@@ -413,8 +417,8 @@ public function testRenderWeeeTaxAttributeWithTax($attribute, $expectedResult)
     public function renderWeeeTaxAttributeAmountWithTaxDataProvider()
     {
         return [
-            [new \Magento\Framework\DataObject(['amount_excl_tax' => 50, 'tax_amount' => 5]), 55],
-            [new \Magento\Framework\DataObject(['amount_excl_tax' => false]), false],
+            [new DataObject(['amount_excl_tax' => 50, 'tax_amount' => 5]), 55],
+            [new DataObject(['amount_excl_tax' => false]), false],
         ];
     }
 }
diff --git a/app/code/Magento/Weee/Test/Unit/Pricing/Render/TaxAdjustmentTest.php b/app/code/Magento/Weee/Test/Unit/Pricing/Render/TaxAdjustmentTest.php
index 02c540fea7073..b247c0617d834 100644
--- a/app/code/Magento/Weee/Test/Unit/Pricing/Render/TaxAdjustmentTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Pricing/Render/TaxAdjustmentTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -6,7 +6,14 @@
 
 namespace Magento\Weee\Test\Unit\Pricing\Render;
 
-class TaxAdjustmentTest extends \PHPUnit\Framework\TestCase
+use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
+use Magento\Weee\Helper\Data;
+use Magento\Weee\Pricing\Adjustment;
+use Magento\Weee\Pricing\Render\TaxAdjustment;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+
+class TaxAdjustmentTest extends TestCase
 {
     /**
      * @var \Magento\Weee\Pricing\Render\TaxAdjustment
@@ -16,29 +23,29 @@ class TaxAdjustmentTest extends \PHPUnit\Framework\TestCase
     /**
      * Weee helper mock
      *
-     * @var \Magento\Weee\Helper\Data | \PHPUnit_Framework_MockObject_MockObject
+     * @var \Magento\Weee\Helper\Data|MockObject
      */
     protected $weeeHelperMock;
 
     /**
-     * @var \Magento\Framework\TestFramework\Unit\Helper\ObjectManager
+     * @var ObjectManager
      */
     protected $objectManager;
 
     /**
      * Init mocks and model
      */
-    protected function setUp()
+    protected function setUp(): void
     {
-        $this->objectManager = new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+        $this->objectManager = new ObjectManager($this);
 
         $this->weeeHelperMock = $this->createPartialMock(
-            \Magento\Weee\Helper\Data::class,
+            Data::class,
             ['typeOfDisplay', 'isTaxable']
         );
 
         $this->model = $this->objectManager->getObject(
-            \Magento\Weee\Pricing\Render\TaxAdjustment::class,
+            TaxAdjustment::class,
             [
                 'weeeHelper' => $this->weeeHelperMock,
             ]
@@ -62,7 +69,7 @@ public function testGetDefaultExclusions($weeeIsExcluded)
         $taxCode = $this->model->getAdjustmentCode(); // since Weee's TaxAdjustment is a subclass of Tax's Adjustment
         $this->assertContains($taxCode, $defaultExclusions);
 
-        $weeeCode = \Magento\Weee\Pricing\Adjustment::ADJUSTMENT_CODE;
+        $weeeCode = Adjustment::ADJUSTMENT_CODE;
         if ($weeeIsExcluded) {
             $this->assertContains($weeeCode, $defaultExclusions);
         } else {
diff --git a/app/code/Magento/Weee/Test/Unit/Pricing/TaxAdjustmentTest.php b/app/code/Magento/Weee/Test/Unit/Pricing/TaxAdjustmentTest.php
index 8abccdc181ad3..884706484ffd5 100644
--- a/app/code/Magento/Weee/Test/Unit/Pricing/TaxAdjustmentTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Pricing/TaxAdjustmentTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -6,9 +6,16 @@
 
 namespace Magento\Weee\Test\Unit\Pricing;
 
+use Magento\Framework\DataObject;
+use Magento\Framework\Pricing\PriceCurrencyInterface;
+use Magento\Framework\Pricing\SaleableInterface;
+use Magento\Weee\Helper\Data;
+use Magento\Weee\Model\Tax;
 use Magento\Weee\Pricing\TaxAdjustment;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
 
-class TaxAdjustmentTest extends \PHPUnit\Framework\TestCase
+class TaxAdjustmentTest extends TestCase
 {
     /**
      * @var TaxAdjustment
@@ -16,17 +23,17 @@ class TaxAdjustmentTest extends \PHPUnit\Framework\TestCase
     protected $adjustment;
 
     /**
-     * @var \Magento\Weee\Helper\Data | \PHPUnit_Framework_MockObject_MockObject
+     * @var Data|MockObject
      */
     protected $weeeHelperMock;
 
     /**
-     * @var \Magento\Tax\Helper\Data | \PHPUnit_Framework_MockObject_MockObject
+     * @var \Magento\Tax\Helper\Data|MockObject
      */
     protected $taxHelperMock;
 
     /**
-     * @var \Magento\Framework\Pricing\PriceCurrencyInterface|\PHPUnit_Framework_MockObject_MockObject
+     * @var PriceCurrencyInterface|MockObject
      */
     protected $priceCurrencyMock;
 
@@ -35,11 +42,11 @@ class TaxAdjustmentTest extends \PHPUnit\Framework\TestCase
      */
     protected $sortOrder = 5;
 
-    protected function setUp()
+    protected function setUp(): void
     {
-        $this->weeeHelperMock = $this->createMock(\Magento\Weee\Helper\Data::class);
+        $this->weeeHelperMock = $this->createMock(Data::class);
         $this->taxHelperMock = $this->createMock(\Magento\Tax\Helper\Data::class);
-        $this->priceCurrencyMock = $this->createMock(\Magento\Framework\Pricing\PriceCurrencyInterface::class);
+        $this->priceCurrencyMock = $this->createMock(PriceCurrencyInterface::class);
         $this->priceCurrencyMock->expects($this->any())
             ->method('convertAndRound')
             ->will(
@@ -101,7 +108,7 @@ public function testIsIncludedInDisplayPrice(
             ->willReturn($taxDisplayExclTax);
 
         $displayTypes = [
-            \Magento\Weee\Model\Tax::DISPLAY_EXCL,
+            Tax::DISPLAY_EXCL,
         ];
         $this->weeeHelperMock->expects($this->any())
             ->method('typeOfDisplay')
@@ -146,13 +153,13 @@ public function isIncludedInDisplayPriceDataProvider()
 
     /**
      * @param float $amount
-     * @param \Magento\Framework\DataObject[] $weeeAttributes
+     * @param DataObject[] $weeeAttributes
      * @param float $expectedResult
      * @dataProvider applyAdjustmentDataProvider
      */
     public function testApplyAdjustment($amount, $weeeAttributes, $expectedResult)
     {
-        $object = $this->getMockForAbstractClass(\Magento\Framework\Pricing\SaleableInterface::class);
+        $object = $this->getMockForAbstractClass(SaleableInterface::class);
 
         $this->weeeHelperMock->expects($this->any())
             ->method('getProductWeeeAttributes')
@@ -170,12 +177,12 @@ public function applyAdjustmentDataProvider()
             [
                 'amount' => 10,
                 'weee_attributes' => [
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'tax_amount' => 5,
                         ]
                     ),
-                    new \Magento\Framework\DataObject(
+                    new DataObject(
                         [
                             'tax_amount' => 2.5,
                         ]
diff --git a/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Form/Modifier/Manager/WebsiteTest.php b/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Form/Modifier/Manager/WebsiteTest.php
index 6671402d49d47..f58e974965959 100644
--- a/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Form/Modifier/Manager/WebsiteTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Form/Modifier/Manager/WebsiteTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
@@ -7,16 +7,15 @@
 
 use Magento\Catalog\Api\Data\ProductInterface;
 use Magento\Catalog\Model\Locator\LocatorInterface;
+use Magento\Catalog\Model\ResourceModel\Eav\Attribute as EavAttribute;
+use Magento\Directory\Helper\Data as DirectoryHelper;
 use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
 use Magento\Store\Model\StoreManagerInterface;
 use Magento\Weee\Ui\DataProvider\Product\Form\Modifier\Manager\Website;
-use Magento\Directory\Helper\Data as DirectoryHelper;
-use Magento\Catalog\Model\ResourceModel\Eav\Attribute as EavAttribute;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
 
-/**
- * Class WebsiteTest
- */
-class WebsiteTest extends \PHPUnit\Framework\TestCase
+class WebsiteTest extends TestCase
 {
     /**
      * @var ObjectManager
@@ -29,31 +28,31 @@ class WebsiteTest extends \PHPUnit\Framework\TestCase
     protected $model;
 
     /**
-     * @var LocatorInterface|\PHPUnit_Framework_MockObject_MockObject
+     * @var LocatorInterface|MockObject
      */
     protected $locatorMock;
 
     /**
-     * @var StoreManagerInterface|\PHPUnit_Framework_MockObject_MockObject
+     * @var StoreManagerInterface|MockObject
      */
     protected $storeManagerMock;
 
     /**
-     * @var DirectoryHelper|\PHPUnit_Framework_MockObject_MockObject
+     * @var DirectoryHelper|MockObject
      */
     protected $directoryHelperMock;
 
     /**
-     * @var EavAttribute|\PHPUnit_Framework_MockObject_MockObject
+     * @var EavAttribute|MockObject
      */
     protected $eavAttributeMock;
 
     /**
-     * @var ProductInterface|\PHPUnit_Framework_MockObject_MockObject
+     * @var ProductInterface|MockObject
      */
     protected $productMock;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->objectManager = new ObjectManager($this);
         $this->locatorMock = $this->getMockBuilder(LocatorInterface::class)
diff --git a/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Form/Modifier/WeeeTest.php b/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Form/Modifier/WeeeTest.php
index 8bd2d24fe160f..f3add900aa9da 100644
--- a/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Form/Modifier/WeeeTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Form/Modifier/WeeeTest.php
@@ -1,44 +1,41 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Ui\DataProvider\Product\Form\Modifier;
 
-use Magento\Catalog\Test\Unit\Ui\DataProvider\Product\Form\Modifier\AbstractModifierTest;
-use Magento\Weee\Ui\DataProvider\Product\Form\Modifier\Weee;
-use Magento\Directory\Model\Config\Source\Country as SourceCountry;
-use Magento\Store\Model\StoreManagerInterface;
 use Magento\Catalog\Model\ResourceModel\Eav\Attribute as EavAttribute;
 use Magento\Catalog\Model\ResourceModel\Eav\AttributeFactory as EavAttributeFactory;
+use Magento\Catalog\Test\Unit\Ui\DataProvider\Product\Form\Modifier\AbstractModifierTest;
+use Magento\Directory\Model\Config\Source\Country as SourceCountry;
 use Magento\Weee\Ui\DataProvider\Product\Form\Modifier\Manager\Website as WebsiteManager;
+use Magento\Weee\Ui\DataProvider\Product\Form\Modifier\Weee;
+use PHPUnit\Framework\MockObject\MockObject;
 
-/**
- * Class WeeeTest
- */
 class WeeeTest extends AbstractModifierTest
 {
     /**
-     * @var SourceCountry|\PHPUnit_Framework_MockObject_MockObject
+     * @var SourceCountry|MockObject
      */
     protected $sourceCountryMock;
 
     /**
-     * @var EavAttributeFactory|\PHPUnit_Framework_MockObject_MockObject
+     * @var EavAttributeFactory|MockObject
      */
     protected $eavAttributeFactoryMock;
 
     /**
-     * @var EavAttribute|\PHPUnit_Framework_MockObject_MockObject
+     * @var EavAttribute|MockObject
      */
     protected $eavAttributeMock;
 
     /**
-     * @var WebsiteManager|\PHPUnit_Framework_MockObject_MockObject
+     * @var WebsiteManager|MockObject
      */
     protected $websiteManagerMock;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         parent::setUp();
         $this->sourceCountryMock = $this->getMockBuilder(SourceCountry::class)
diff --git a/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Listing/Collector/WeeeTest.php b/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Listing/Collector/WeeeTest.php
index 266737089cd21..cf3012dbcc2b7 100644
--- a/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Listing/Collector/WeeeTest.php
+++ b/app/code/Magento/Weee/Test/Unit/Ui/DataProvider/Product/Listing/Collector/WeeeTest.php
@@ -1,55 +1,61 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
 namespace Magento\Weee\Test\Unit\Ui\DataProvider\Product\Listing\Collector;
 
+use Magento\Catalog\Api\Data\ProductRender\PriceInfoExtensionInterface;
 use Magento\Catalog\Api\Data\ProductRender\PriceInfoExtensionInterfaceFactory;
 use Magento\Catalog\Api\Data\ProductRenderInterface;
 use Magento\Catalog\Model\Product;
 use Magento\Catalog\Model\ProductRender\FormattedPriceInfoBuilder;
+use Magento\Catalog\Pricing\Price\FinalPrice;
 use Magento\Framework\Pricing\Amount\AmountInterface;
-use Magento\Catalog\Api\Data\ProductRender\PriceInfoExtensionInterface;
-use Magento\Weee\Api\Data\ProductRender\WeeeAdjustmentAttributeInterfaceFactory;
+use Magento\Framework\Pricing\PriceCurrencyInterface;
+use Magento\Framework\Pricing\PriceInfo\Base;
 use Magento\Weee\Api\Data\ProductRender\WeeeAdjustmentAttributeInterface;
+use Magento\Weee\Api\Data\ProductRender\WeeeAdjustmentAttributeInterfaceFactory;
+use Magento\Weee\Helper\Data;
 use Magento\Weee\Ui\DataProvider\Product\Listing\Collector\Weee;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
-class WeeeTest extends \PHPUnit\Framework\TestCase
+class WeeeTest extends TestCase
 {
     /** @var Weee */
     protected $model;
 
-    /** @var \Magento\Weee\Helper\Data|\PHPUnit_Framework_MockObject_MockObject */
+    /** @var Data|MockObject */
     protected $weeeHelperMock;
 
-    /** @var \Magento\Framework\Pricing\PriceCurrencyInterface|\PHPUnit_Framework_MockObject_MockObject */
+    /** @var PriceCurrencyInterface|MockObject */
     protected $priceCurrencyMock;
 
-    /** @var PriceInfoExtensionInterface|\PHPUnit_Framework_MockObject_MockObject */
+    /** @var PriceInfoExtensionInterface|MockObject */
     private $extensionAttributes;
 
-    /** @var WeeeAdjustmentAttributeInterfaceFactory|\PHPUnit_Framework_MockObject_MockObject */
+    /** @var WeeeAdjustmentAttributeInterfaceFactory|MockObject */
     private $weeeAdjustmentAttributeFactory;
 
-    /** @var PriceInfoExtensionInterfaceFactory|\PHPUnit_Framework_MockObject_MockObject */
+    /** @var PriceInfoExtensionInterfaceFactory|MockObject */
     private $priceInfoExtensionFactory;
 
-    /** @var FormattedPriceInfoBuilder|\PHPUnit_Framework_MockObject_MockObject */
+    /** @var FormattedPriceInfoBuilder|MockObject */
     private $formattedPriceInfoBuilder;
 
     /**
      * @return void
      */
-    protected function setUp()
+    protected function setUp(): void
     {
-        $this->weeeHelperMock = $this->getMockBuilder(\Magento\Weee\Helper\Data::class)
+        $this->weeeHelperMock = $this->getMockBuilder(Data::class)
             ->disableOriginalConstructor()
             ->getMock();
-        $this->priceCurrencyMock = $this->getMockBuilder(\Magento\Framework\Pricing\PriceCurrencyInterface::class)
+        $this->priceCurrencyMock = $this->getMockBuilder(PriceCurrencyInterface::class)
             ->getMockForAbstractClass();
 
         $this->weeeAdjustmentAttributeFactory = $this->getMockBuilder(WeeeAdjustmentAttributeInterfaceFactory::class)
@@ -96,11 +102,11 @@ public function testCollect()
         $this->weeeAdjustmentAttributeFactory->expects($this->atLeastOnce())
             ->method('create')
             ->willReturn($weeAttribute);
-        $priceInfo = $this->getMockBuilder(\Magento\Framework\Pricing\PriceInfo\Base::class)
+        $priceInfo = $this->getMockBuilder(Base::class)
             ->disableOriginalConstructor()
             ->setMethods(['getExtensionAttributes', 'getPrice', 'setExtensionAttributes'])
             ->getMock();
-        $price = $this->getMockBuilder(\Magento\Catalog\Pricing\Price\FinalPrice::class)
+        $price = $this->getMockBuilder(FinalPrice::class)
             ->disableOriginalConstructor()
             ->getMock();
         $weeAttribute->expects($this->once())