diff --git a/app/code/Magento/AdvancedPricingImportExport/Test/Unit/Model/Export/AdvancedPricingTest.php b/app/code/Magento/AdvancedPricingImportExport/Test/Unit/Model/Export/AdvancedPricingTest.php
index 48b4c58918740..17e7ffc20c5e9 100644
--- a/app/code/Magento/AdvancedPricingImportExport/Test/Unit/Model/Export/AdvancedPricingTest.php
+++ b/app/code/Magento/AdvancedPricingImportExport/Test/Unit/Model/Export/AdvancedPricingTest.php
@@ -213,7 +213,7 @@ protected function setUp()
             '_getCustomerGroupById',
             'correctExportData'
         ]);
-        $this->advancedPricing = $this->getMockbuilder(
+        $this->advancedPricing = $this->getMockBuilder(
             \Magento\AdvancedPricingImportExport\Model\Export\AdvancedPricing::class
         )
             ->setMethods($mockMethods)
diff --git a/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/AdditionalCommentTest.php b/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/AdditionalCommentTest.php
index cbf06264096ac..407e323aeaae6 100644
--- a/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/AdditionalCommentTest.php
+++ b/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/AdditionalCommentTest.php
@@ -65,11 +65,11 @@ public function testRender()
             ->method('getLabel')
             ->willReturn('Comment label');
         $html = $this->additionalComment->render($this->abstractElementMock);
-        $this->assertRegexp(
+        $this->assertRegExp(
             "/New comment/",
             $html
         );
-        $this->assertRegexp(
+        $this->assertRegExp(
             "/Comment label/",
             $html
         );
diff --git a/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/CollectionTimeLabelTest.php b/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/CollectionTimeLabelTest.php
index 462b3c909a7fd..d567d65882350 100644
--- a/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/CollectionTimeLabelTest.php
+++ b/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/CollectionTimeLabelTest.php
@@ -87,7 +87,7 @@ public function testRender()
         $this->localeResolver->expects($this->once())
             ->method('getLocale')
             ->willReturn('en_US');
-        $this->assertRegexp(
+        $this->assertRegExp(
             "/Eastern Standard Time \(America\/New_York\)/",
             $this->collectionTimeLabel->render($this->abstractElementMock)
         );
diff --git a/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/SubscriptionStatusLabelTest.php b/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/SubscriptionStatusLabelTest.php
index d643bc05cc615..78ff581f3de9d 100644
--- a/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/SubscriptionStatusLabelTest.php
+++ b/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/SubscriptionStatusLabelTest.php
@@ -74,7 +74,7 @@ public function testRender()
         $this->abstractElementMock->expects($this->any())
             ->method('getComment')
             ->willReturn('Subscription status: Enabled');
-        $this->assertRegexp(
+        $this->assertRegExp(
             "/Subscription status: Enabled/",
             $this->subscriptionStatusLabel->render($this->abstractElementMock)
         );
diff --git a/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/VerticalTest.php b/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/VerticalTest.php
index abce48c36c86a..6a0cecc781062 100644
--- a/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/VerticalTest.php
+++ b/app/code/Magento/Analytics/Test/Unit/Block/Adminhtml/System/Config/VerticalTest.php
@@ -65,7 +65,7 @@ public function testRender()
             ->method('getHint')
             ->willReturn('New hint');
         $html = $this->vertical->render($this->abstractElementMock);
-        $this->assertRegexp(
+        $this->assertRegExp(
             "/New comment/",
             $html
         );
diff --git a/app/code/Magento/Braintree/Gateway/Response/CardDetailsHandler.php b/app/code/Magento/Braintree/Gateway/Response/CardDetailsHandler.php
index e89e604867baa..32abeac4c8ffb 100644
--- a/app/code/Magento/Braintree/Gateway/Response/CardDetailsHandler.php
+++ b/app/code/Magento/Braintree/Gateway/Response/CardDetailsHandler.php
@@ -85,7 +85,7 @@ public function handle(array $handlingSubject, array $response)
     private function getCreditCardType($type)
     {
         $replaced = str_replace(' ', '-', strtolower($type));
-        $mapper = $this->config->getCctypesMapper();
+        $mapper = $this->config->getCcTypesMapper();
 
         return $mapper[$replaced];
     }
diff --git a/app/code/Magento/Braintree/Gateway/Response/VaultDetailsHandler.php b/app/code/Magento/Braintree/Gateway/Response/VaultDetailsHandler.php
index 7c307185b4c22..8880f9c1b1a3e 100644
--- a/app/code/Magento/Braintree/Gateway/Response/VaultDetailsHandler.php
+++ b/app/code/Magento/Braintree/Gateway/Response/VaultDetailsHandler.php
@@ -157,7 +157,7 @@ private function convertDetailsToJSON($details)
     private function getCreditCardType($type)
     {
         $replaced = str_replace(' ', '-', strtolower($type));
-        $mapper = $this->config->getCctypesMapper();
+        $mapper = $this->config->getCcTypesMapper();
 
         return $mapper[$replaced];
     }
diff --git a/app/code/Magento/Braintree/Model/Ui/ConfigProvider.php b/app/code/Magento/Braintree/Model/Ui/ConfigProvider.php
index fe30e790de07c..928769498a035 100644
--- a/app/code/Magento/Braintree/Model/Ui/ConfigProvider.php
+++ b/app/code/Magento/Braintree/Model/Ui/ConfigProvider.php
@@ -70,7 +70,7 @@ public function getConfig()
                 self::CODE => [
                     'isActive' => $this->config->isActive($storeId),
                     'clientToken' => $this->getClientToken(),
-                    'ccTypesMapper' => $this->config->getCctypesMapper(),
+                    'ccTypesMapper' => $this->config->getCcTypesMapper(),
                     'sdkUrl' => $this->config->getSdkUrl(),
                     'countrySpecificCardTypes' => $this->config->getCountrySpecificCardTypeConfig($storeId),
                     'availableCardTypes' => $this->config->getAvailableCardTypes($storeId),
diff --git a/app/code/Magento/Braintree/Test/Unit/Gateway/Config/ConfigTest.php b/app/code/Magento/Braintree/Test/Unit/Gateway/Config/ConfigTest.php
index 7b9d59a5bc482..36ea3aea465dd 100644
--- a/app/code/Magento/Braintree/Test/Unit/Gateway/Config/ConfigTest.php
+++ b/app/code/Magento/Braintree/Test/Unit/Gateway/Config/ConfigTest.php
@@ -142,7 +142,7 @@ public function testGetCcTypesMapper($value, $expected)
 
         static::assertEquals(
             $expected,
-            $this->model->getCctypesMapper()
+            $this->model->getCcTypesMapper()
         );
     }
 
diff --git a/app/code/Magento/Catalog/Test/Unit/Controller/Adminhtml/Product/ShowUpdateResultTest.php b/app/code/Magento/Catalog/Test/Unit/Controller/Adminhtml/Product/ShowUpdateResultTest.php
index ba716fdb53c89..47a60a1916142 100644
--- a/app/code/Magento/Catalog/Test/Unit/Controller/Adminhtml/Product/ShowUpdateResultTest.php
+++ b/app/code/Magento/Catalog/Test/Unit/Controller/Adminhtml/Product/ShowUpdateResultTest.php
@@ -58,7 +58,7 @@ protected function getContext()
         $objectManagerMock = $this->getMockForAbstractClass(\Magento\Framework\ObjectManagerInterface::class);
         $objectManagerMock->expects($this->any())
             ->method('get')
-            ->willreturn($productActionMock);
+            ->willReturn($productActionMock);
 
         $eventManager = $this->getMockBuilder(\Magento\Framework\Event\Manager::class)
             ->setMethods(['dispatch'])
diff --git a/app/code/Magento/Checkout/Setup/Patch/Data/PrepareInitialCheckoutConfiguration.php b/app/code/Magento/Checkout/Setup/Patch/Data/PrepareInitialCheckoutConfiguration.php
index bc38809d070b2..47a19fb3234fd 100644
--- a/app/code/Magento/Checkout/Setup/Patch/Data/PrepareInitialCheckoutConfiguration.php
+++ b/app/code/Magento/Checkout/Setup/Patch/Data/PrepareInitialCheckoutConfiguration.php
@@ -817,7 +817,7 @@ public function apply()
 
                 $connection->commit();
             } catch (\Exception $e) {
-                $connection->rollback();
+                $connection->rollBack();
                 throw $e;
             }
         }
diff --git a/app/code/Magento/Customer/Test/Unit/Model/Customer/DataProviderTest.php b/app/code/Magento/Customer/Test/Unit/Model/Customer/DataProviderTest.php
index 029949c5f35b0..71b99586f6fb4 100644
--- a/app/code/Magento/Customer/Test/Unit/Model/Customer/DataProviderTest.php
+++ b/app/code/Magento/Customer/Test/Unit/Model/Customer/DataProviderTest.php
@@ -1266,7 +1266,7 @@ public function testGetDataWithVisibleAttributesWithAccountEdit()
         $helper = new ObjectManager($this);
         $context = $this->getMockBuilder(\Magento\Framework\View\Element\UiComponent\ContextInterface::class)
             ->setMethods(['getRequestParam'])
-            ->getMockforAbstractClass();
+            ->getMockForAbstractClass();
         $context->expects($this->any())
             ->method('getRequestParam')
             ->with('request-field-name')
diff --git a/app/code/Magento/Eav/Test/Unit/Model/ResourceModel/Attribute/CollectionTest.php b/app/code/Magento/Eav/Test/Unit/Model/ResourceModel/Attribute/CollectionTest.php
index d988dfc63c959..a9aead6325c39 100644
--- a/app/code/Magento/Eav/Test/Unit/Model/ResourceModel/Attribute/CollectionTest.php
+++ b/app/code/Magento/Eav/Test/Unit/Model/ResourceModel/Attribute/CollectionTest.php
@@ -115,7 +115,7 @@ protected function setUp()
         $this->connectionMock->expects($this->any())->method('quoteIdentifier')->will($this->returnArgument(0));
         $this->connectionMock->expects($this->any())
             ->method('describeTable')
-            ->will($this->returnvalueMap(
+            ->will($this->returnValueMap(
                 [
                     [
                         'some_main_table',
diff --git a/app/code/Magento/Newsletter/Model/ResourceModel/Problem/Collection.php b/app/code/Magento/Newsletter/Model/ResourceModel/Problem/Collection.php
index c0c5dfef277b8..0d7ebd74f724f 100644
--- a/app/code/Magento/Newsletter/Model/ResourceModel/Problem/Collection.php
+++ b/app/code/Magento/Newsletter/Model/ResourceModel/Problem/Collection.php
@@ -165,8 +165,8 @@ protected function _addCustomersData()
                     $customerName = $this->_customerView->getCustomerName($customer);
                     foreach ($problems as $problem) {
                         $problem->setCustomerName($customerName)
-                            ->setCustomerFirstName($customer->getFirstName())
-                            ->setCustomerLastName($customer->getLastName());
+                            ->setCustomerFirstName($customer->getFirstname())
+                            ->setCustomerLastName($customer->getLastname());
                     }
                 } catch (NoSuchEntityException $e) {
                     // do nothing if customer is not found by id
diff --git a/app/code/Magento/Newsletter/Model/ResourceModel/Queue/Collection.php b/app/code/Magento/Newsletter/Model/ResourceModel/Queue/Collection.php
index 9e98998f7f6ec..189549d2a73d2 100644
--- a/app/code/Magento/Newsletter/Model/ResourceModel/Queue/Collection.php
+++ b/app/code/Magento/Newsletter/Model/ResourceModel/Queue/Collection.php
@@ -221,7 +221,7 @@ public function addOnlyForSendingFilter()
             [\Magento\Newsletter\Model\Queue::STATUS_SENDING, \Magento\Newsletter\Model\Queue::STATUS_NEVER]
         )->where(
             'main_table.queue_start_at < ?',
-            $this->_date->gmtdate()
+            $this->_date->gmtDate()
         )->where(
             'main_table.queue_start_at IS NOT NULL'
         );
diff --git a/app/code/Magento/OfflineShipping/Model/ResourceModel/Carrier/Tablerate.php b/app/code/Magento/OfflineShipping/Model/ResourceModel/Carrier/Tablerate.php
index fc36eaf6a97db..0c4718245928b 100644
--- a/app/code/Magento/OfflineShipping/Model/ResourceModel/Carrier/Tablerate.php
+++ b/app/code/Magento/OfflineShipping/Model/ResourceModel/Carrier/Tablerate.php
@@ -320,7 +320,7 @@ public function getConditionName(\Magento\Framework\DataObject $object)
      */
     private function getCsvFile($filePath)
     {
-        $pathInfo = pathInfo($filePath);
+        $pathInfo = pathinfo($filePath);
         $dirName = isset($pathInfo['dirname']) ? $pathInfo['dirname'] : '';
         $fileName = isset($pathInfo['basename']) ? $pathInfo['basename'] : '';
 
diff --git a/app/code/Magento/Quote/Test/Unit/Model/GuestCart/GuestCartManagementTest.php b/app/code/Magento/Quote/Test/Unit/Model/GuestCart/GuestCartManagementTest.php
index ee0ffd3bcc666..73ed2e65b41a9 100644
--- a/app/code/Magento/Quote/Test/Unit/Model/GuestCart/GuestCartManagementTest.php
+++ b/app/code/Magento/Quote/Test/Unit/Model/GuestCart/GuestCartManagementTest.php
@@ -94,7 +94,7 @@ public function testCreateEmptyCart()
         $cartId = 1;
         $this->quoteIdMaskMock->expects($this->once())->method('setQuoteId')->with($cartId)->willReturnSelf();
         $this->quoteIdMaskMock->expects($this->once())->method('save')->willReturnSelf();
-        $this->quoteIdMaskMock->expects($this->once())->method('getMaskedId')->willreturn($maskedCartId);
+        $this->quoteIdMaskMock->expects($this->once())->method('getMaskedId')->willReturn($maskedCartId);
         $this->quoteIdMaskFactoryMock->expects($this->once())->method('create')->willReturn($this->quoteIdMaskMock);
         $this->quoteManagementMock->expects($this->once())->method('createEmptyCart')->willReturn($cartId);
 
diff --git a/app/code/Magento/Sales/Controller/Adminhtml/Order/Unhold.php b/app/code/Magento/Sales/Controller/Adminhtml/Order/Unhold.php
index 752ab088689c8..fa9676856a442 100644
--- a/app/code/Magento/Sales/Controller/Adminhtml/Order/Unhold.php
+++ b/app/code/Magento/Sales/Controller/Adminhtml/Order/Unhold.php
@@ -32,7 +32,7 @@ public function execute()
                 if (!$order->canUnhold()) {
                     throw new \Magento\Framework\Exception\LocalizedException(__('Can\'t unhold order.'));
                 }
-                $this->orderManagement->unhold($order->getEntityId());
+                $this->orderManagement->unHold($order->getEntityId());
                 $this->messageManager->addSuccess(__('You released the order from holding status.'));
             } catch (\Magento\Framework\Exception\LocalizedException $e) {
                 $this->messageManager->addError($e->getMessage());
diff --git a/app/code/Magento/Sales/Test/Unit/Block/Order/Create/TotalsTest.php b/app/code/Magento/Sales/Test/Unit/Block/Order/Create/TotalsTest.php
index 2a839dd018dba..492cfee5f5d83 100644
--- a/app/code/Magento/Sales/Test/Unit/Block/Order/Create/TotalsTest.php
+++ b/app/code/Magento/Sales/Test/Unit/Block/Order/Create/TotalsTest.php
@@ -70,10 +70,10 @@ protected function setUp()
 
         $this->quoteMock->expects($this->any())
             ->method('getBillingAddress')
-            ->willreturn($this->billingAddressMock);
+            ->willReturn($this->billingAddressMock);
         $this->quoteMock->expects($this->any())
             ->method('getShippingAddress')
-            ->willreturn($this->shippingAddressMock);
+            ->willReturn($this->shippingAddressMock);
         $this->sessionQuoteMock->expects($this->any())->method('getQuote')->willReturn($this->quoteMock);
         $this->totals = $this->helperManager->getObject(
             \Magento\Sales\Block\Adminhtml\Order\Create\Totals::class,
@@ -88,7 +88,7 @@ public function testGetTotals($isVirtual)
     {
         $expected = 'expected';
         $this->quoteMock->expects($this->at(1))->method('collectTotals');
-        $this->quoteMock->expects($this->once())->method('isVirtual')->willreturn($isVirtual);
+        $this->quoteMock->expects($this->once())->method('isVirtual')->willReturn($isVirtual);
         if ($isVirtual) {
             $this->billingAddressMock->expects($this->once())->method('getTotals')->willReturn($expected);
         } else {
diff --git a/app/code/Magento/SalesRule/Model/ResourceModel/Rule.php b/app/code/Magento/SalesRule/Model/ResourceModel/Rule.php
index 794fc94d6a2a8..3a5ed16fdd2fd 100644
--- a/app/code/Magento/SalesRule/Model/ResourceModel/Rule.php
+++ b/app/code/Magento/SalesRule/Model/ResourceModel/Rule.php
@@ -239,7 +239,7 @@ public function saveStoreLabels($ruleId, $labels)
                 $connection->delete($table, ['rule_id=?' => $ruleId, 'store_id IN (?)' => $deleteByStoreIds]);
             }
         } catch (\Exception $e) {
-            $connection->rollback();
+            $connection->rollBack();
             throw $e;
         }
         $connection->commit();
diff --git a/app/code/Magento/Shipping/Model/Shipping/Labels.php b/app/code/Magento/Shipping/Model/Shipping/Labels.php
index 5c796d9fa6897..08ce168567182 100644
--- a/app/code/Magento/Shipping/Model/Shipping/Labels.php
+++ b/app/code/Magento/Shipping/Model/Shipping/Labels.php
@@ -117,8 +117,8 @@ public function requestToShipment(Shipment $orderShipment)
             )
         );
 
-        if (!$admin->getFirstname()
-            || !$admin->getLastname()
+        if (!$admin->getFirstName()
+            || !$admin->getLastName()
             || !$storeInfo->getName()
             || !$storeInfo->getPhone()
             || !$originStreet1
@@ -188,8 +188,8 @@ protected function setShipperDetails(
         );
 
         $request->setShipperContactPersonName($storeAdmin->getName());
-        $request->setShipperContactPersonFirstName($storeAdmin->getFirstname());
-        $request->setShipperContactPersonLastName($storeAdmin->getLastname());
+        $request->setShipperContactPersonFirstName($storeAdmin->getFirstName());
+        $request->setShipperContactPersonLastName($storeAdmin->getLastName());
         $request->setShipperContactCompanyName($store->getName());
         $request->setShipperContactPhoneNumber($store->getPhone());
         $request->setShipperEmail($storeAdmin->getEmail());
diff --git a/app/code/Magento/Tax/Test/Unit/Model/TaxClass/Type/CustomerTest.php b/app/code/Magento/Tax/Test/Unit/Model/TaxClass/Type/CustomerTest.php
index fc27e68c8e55b..707b999c5e467 100644
--- a/app/code/Magento/Tax/Test/Unit/Model/TaxClass/Type/CustomerTest.php
+++ b/app/code/Magento/Tax/Test/Unit/Model/TaxClass/Type/CustomerTest.php
@@ -26,9 +26,9 @@ public function testIsAssignedToObjects()
 
         $filterBuilder->expects($this->once())->method('setField')->with(
             \Magento\Customer\Api\Data\GroupInterface::TAX_CLASS_ID
-        )->willReturnself();
-        $filterBuilder->expects($this->once())->method('setValue')->willReturnself();
-        $filterBuilder->expects($this->once())->method('create')->willReturnself();
+        )->willReturnSelf();
+        $filterBuilder->expects($this->once())->method('setValue')->willReturnSelf();
+        $filterBuilder->expects($this->once())->method('create')->willReturnSelf();
 
         $filterGroupBuilder = $this->createMock(\Magento\Framework\Api\Search\FilterGroupBuilder::class);
         $searchCriteriaBuilder = $this->getMockBuilder(\Magento\Framework\Api\SearchCriteriaBuilder::class)
diff --git a/app/code/Magento/Theme/Test/Unit/Controller/Adminhtml/System/Design/Theme/UploadJsTest.php b/app/code/Magento/Theme/Test/Unit/Controller/Adminhtml/System/Design/Theme/UploadJsTest.php
index d5919db5edcba..bbcaa87acb9c3 100644
--- a/app/code/Magento/Theme/Test/Unit/Controller/Adminhtml/System/Design/Theme/UploadJsTest.php
+++ b/app/code/Magento/Theme/Test/Unit/Controller/Adminhtml/System/Design/Theme/UploadJsTest.php
@@ -63,22 +63,22 @@ public function testExecuteWithoutTheme()
             ->expects($this->at(0))
             ->method('get')
             ->with(\Magento\Theme\Model\Uploader\Service::class)
-            ->WillReturn($this->serviceModel);
+            ->willReturn($this->serviceModel);
         $this->_objectManagerMock
             ->expects($this->at(1))
             ->method('get')
             ->with(\Magento\Framework\View\Design\Theme\FlyweightFactory::class)
-            ->WillReturn($this->themeFactory);
+            ->willReturn($this->themeFactory);
         $this->_objectManagerMock
             ->expects($this->at(2))
             ->method('get')
             ->with(\Magento\Framework\View\Design\Theme\Customization\File\Js::class)
-            ->WillReturn($this->customizationJs);
+            ->willReturn($this->customizationJs);
         $this->_objectManagerMock
             ->expects($this->at(3))
             ->method('get')
             ->with(\Magento\Framework\Json\Helper\Data::class)
-            ->WillReturn($this->jsonHelper);
+            ->willReturn($this->jsonHelper);
 
         $this->themeFactory->expects($this->once())
             ->method('create')
@@ -107,21 +107,21 @@ public function testExecuteWithException()
         $this->_objectManagerMock->expects($this->at(0))
             ->method('get')
             ->with(\Magento\Theme\Model\Uploader\Service::class)
-            ->WillReturn($this->serviceModel);
+            ->willReturn($this->serviceModel);
         $this->_objectManagerMock->expects($this->at(1))
             ->method('get')
             ->with(\Magento\Framework\View\Design\Theme\FlyweightFactory::class)
-            ->WillReturn($this->themeFactory);
+            ->willReturn($this->themeFactory);
         $this->_objectManagerMock
             ->expects($this->at(2))
             ->method('get')
             ->with(\Magento\Framework\View\Design\Theme\Customization\File\Js::class)
-            ->WillReturn($this->customizationJs);
+            ->willReturn($this->customizationJs);
         $this->_objectManagerMock
             ->expects($this->at(4))
             ->method('get')
             ->with(\Magento\Framework\Json\Helper\Data::class)
-            ->WillReturn($this->jsonHelper);
+            ->willReturn($this->jsonHelper);
 
         $this->themeFactory->expects($this->once())
             ->method('create')
@@ -172,19 +172,19 @@ public function testExecute()
         $this->_objectManagerMock->expects($this->at(0))
             ->method('get')
             ->with(\Magento\Theme\Model\Uploader\Service::class)
-            ->WillReturn($this->serviceModel);
+            ->willReturn($this->serviceModel);
         $this->_objectManagerMock->expects($this->at(1))
             ->method('get')
             ->with(\Magento\Framework\View\Design\Theme\FlyweightFactory::class)
-            ->WillReturn($this->themeFactory);
+            ->willReturn($this->themeFactory);
         $this->_objectManagerMock->expects($this->at(2))
             ->method('get')
             ->with(\Magento\Framework\View\Design\Theme\Customization\File\Js::class)
-            ->WillReturn($this->customizationJs);
+            ->willReturn($this->customizationJs);
         $this->_objectManagerMock->expects($this->at(4))
             ->method('get')
             ->with(\Magento\Framework\Json\Helper\Data::class)
-            ->WillReturn($this->jsonHelper);
+            ->willReturn($this->jsonHelper);
 
         $this->themeFactory->expects($this->once())
             ->method('create')
diff --git a/app/code/Magento/User/Test/Unit/Model/ResourceModel/UserTest.php b/app/code/Magento/User/Test/Unit/Model/ResourceModel/UserTest.php
index 16cde3cfe2c06..1cc0cd54c60eb 100644
--- a/app/code/Magento/User/Test/Unit/Model/ResourceModel/UserTest.php
+++ b/app/code/Magento/User/Test/Unit/Model/ResourceModel/UserTest.php
@@ -330,7 +330,7 @@ public function testDeleteFromRole()
         $roleId = 44;
         $methodUserMock->expects($this->once())->method('getUserId')->willReturn($uid);
         $this->resourceMock->expects($this->atLeastOnce())->method('getConnection')->willReturn($this->dbAdapterMock);
-        $methodUserMock->expects($this->atleastOnce())->method('getRoleId')->willReturn($roleId);
+        $methodUserMock->expects($this->atLeastOnce())->method('getRoleId')->willReturn($roleId);
         $this->dbAdapterMock->expects($this->once())->method('delete');
 
         $this->assertInstanceOf(
diff --git a/lib/internal/Magento/Framework/App/Test/Unit/BootstrapTest.php b/lib/internal/Magento/Framework/App/Test/Unit/BootstrapTest.php
index 1e2947084ee6b..4b04507dcedc0 100644
--- a/lib/internal/Magento/Framework/App/Test/Unit/BootstrapTest.php
+++ b/lib/internal/Magento/Framework/App/Test/Unit/BootstrapTest.php
@@ -135,7 +135,7 @@ public function testCreateFilesystemDriverPool()
         );
         /** @var \Magento\Framework\Filesystem\DriverPool $result */
         $this->assertInstanceOf(\Magento\Framework\Filesystem\DriverPool::class, $result);
-        $this->assertInstanceof($driverClass, $result->getDriver('custom'));
+        $this->assertInstanceOf($driverClass, $result->getDriver('custom'));
     }
 
     public function testGetParams()
diff --git a/lib/internal/Magento/Framework/Composer/Test/Unit/DependencyCheckerTest.php b/lib/internal/Magento/Framework/Composer/Test/Unit/DependencyCheckerTest.php
index 801d99373bc50..15ceb0c6c2755 100644
--- a/lib/internal/Magento/Framework/Composer/Test/Unit/DependencyCheckerTest.php
+++ b/lib/internal/Magento/Framework/Composer/Test/Unit/DependencyCheckerTest.php
@@ -69,7 +69,7 @@ function ($input, $buffer) {
                 $buffer->writeln($output);
             }
         );
-        $composerApp->Expects($this->at(6))->method('run')->willReturnCallback(
+        $composerApp->expects($this->at(6))->method('run')->willReturnCallback(
             function ($input, $buffer) {
                 $output = 'magento/package-d requires magento/package-c (1.0)' . PHP_EOL .
                     'magento/project-community-edition requires magento/package-a (1.0)' . PHP_EOL;
diff --git a/lib/internal/Magento/Framework/File/Size.php b/lib/internal/Magento/Framework/File/Size.php
index 6f48024f71c16..c259069637293 100644
--- a/lib/internal/Magento/Framework/File/Size.php
+++ b/lib/internal/Magento/Framework/File/Size.php
@@ -36,7 +36,7 @@ class Size
      */
     public function getPostMaxSize()
     {
-        return $this->_iniget('post_max_size');
+        return $this->_iniGet('post_max_size');
     }
 
     /**
@@ -46,7 +46,7 @@ public function getPostMaxSize()
      */
     public function getUploadMaxSize()
     {
-        return $this->_iniget('upload_max_filesize');
+        return $this->_iniGet('upload_max_filesize');
     }
 
     /**
diff --git a/lib/internal/Magento/Framework/Image/Adapter/Gd2.php b/lib/internal/Magento/Framework/Image/Adapter/Gd2.php
index 93274b1d063bf..ea21faf3f340d 100644
--- a/lib/internal/Magento/Framework/Image/Adapter/Gd2.php
+++ b/lib/internal/Magento/Framework/Image/Adapter/Gd2.php
@@ -106,7 +106,7 @@ protected function _getImageNeedMemorySize($file)
         }
 
         return round(
-            ($imageInfo[0] * $imageInfo[1] * $imageInfo['bits'] * $imageInfo['channels'] / 8 + Pow(2, 16)) * 1.65
+            ($imageInfo[0] * $imageInfo[1] * $imageInfo['bits'] * $imageInfo['channels'] / 8 + pow(2, 16)) * 1.65
         );
     }
 
@@ -426,7 +426,7 @@ public function watermark($imagePath, $positionX = 0, $positionY = 0, $opacity =
             imagecolortransparent($newWatermark, $col);
             imagefilledrectangle($newWatermark, 0, 0, $this->getWatermarkWidth(), $this->getWatermarkHeight(), $col);
             imagealphablending($newWatermark, true);
-            imageSaveAlpha($newWatermark, true);
+            imagesavealpha($newWatermark, true);
             imagecopyresampled(
                 $newWatermark,
                 $watermark,
@@ -451,7 +451,7 @@ public function watermark($imagePath, $positionX = 0, $positionY = 0, $opacity =
             imagecolortransparent($newWatermark, $col);
             imagefilledrectangle($newWatermark, 0, 0, $this->_imageSrcWidth, $this->_imageSrcHeight, $col);
             imagealphablending($newWatermark, true);
-            imageSaveAlpha($newWatermark, true);
+            imagesavealpha($newWatermark, true);
             imagecopyresampled(
                 $newWatermark,
                 $watermark,
@@ -669,7 +669,7 @@ private function imageDestroy()
     private function _saveAlpha($imageHandler)
     {
         $background = imagecolorallocate($imageHandler, 0, 0, 0);
-        ImageColorTransparent($imageHandler, $background);
+        imagecolortransparent($imageHandler, $background);
         imagealphablending($imageHandler, false);
         imagesavealpha($imageHandler, true);
     }
diff --git a/lib/internal/Magento/Framework/Indexer/Action/Base.php b/lib/internal/Magento/Framework/Indexer/Action/Base.php
index 11cf1cec62636..636335192cbc5 100644
--- a/lib/internal/Magento/Framework/Indexer/Action/Base.php
+++ b/lib/internal/Magento/Framework/Indexer/Action/Base.php
@@ -221,7 +221,7 @@ protected function prepareDataSource(array $ids = [])
     {
         return !count($ids)
             ? $this->createResultCollection()
-            : $this->createResultCollection()->addFieldToFilter($this->getPrimaryResource()->getIdFieldname(), $ids);
+            : $this->createResultCollection()->addFieldToFilter($this->getPrimaryResource()->getIdFieldName(), $ids);
     }
 
     /**
diff --git a/lib/internal/Magento/Framework/RequireJs/Config.php b/lib/internal/Magento/Framework/RequireJs/Config.php
index 08131b2cccea3..ae45e29f38911 100644
--- a/lib/internal/Magento/Framework/RequireJs/Config.php
+++ b/lib/internal/Magento/Framework/RequireJs/Config.php
@@ -157,7 +157,7 @@ public function getConfig()
         $customConfigFiles = $this->fileSource->getFiles($this->design->getDesignTheme(), self::CONFIG_FILE_NAME);
         foreach ($customConfigFiles as $file) {
             /** @var $fileReader \Magento\Framework\Filesystem\File\Read */
-            $fileReader = $this->readFactory->create($file->getFileName(), DriverPool::FILE);
+            $fileReader = $this->readFactory->create($file->getFilename(), DriverPool::FILE);
             $config = $fileReader->readAll($file->getName());
             $distributedConfig .= str_replace(
                 ['%config%', '%context%'],
diff --git a/lib/internal/Magento/Framework/View/Element/UiComponent/Config/FileCollector/AggregatedFileCollector.php b/lib/internal/Magento/Framework/View/Element/UiComponent/Config/FileCollector/AggregatedFileCollector.php
index 17a320164dad3..9ba7833a355d7 100644
--- a/lib/internal/Magento/Framework/View/Element/UiComponent/Config/FileCollector/AggregatedFileCollector.php
+++ b/lib/internal/Magento/Framework/View/Element/UiComponent/Config/FileCollector/AggregatedFileCollector.php
@@ -75,7 +75,7 @@ public function collectFiles($searchPattern = null)
         }
         $files = $this->collectorAggregated->getFiles($this->design->getDesignTheme(), $searchPattern);
         foreach ($files as $file) {
-            $fullFileName = $file->getFileName();
+            $fullFileName = $file->getFilename();
             $fileDir = dirname($fullFileName);
             $fileName = basename($fullFileName);
             $dirRead = $this->readFactory->create($fileDir);
diff --git a/lib/internal/Magento/Framework/View/Model/Layout/Merge.php b/lib/internal/Magento/Framework/View/Model/Layout/Merge.php
index fe5c94ed21b30..5a19f4f0b9b58 100644
--- a/lib/internal/Magento/Framework/View/Model/Layout/Merge.php
+++ b/lib/internal/Magento/Framework/View/Model/Layout/Merge.php
@@ -672,7 +672,7 @@ public function getFileLayoutUpdatesXml()
             $result = $this->_loadXmlString($result);
         } else {
             $result = $this->_loadFileLayoutUpdatesXml();
-            $this->_saveCache($result->asXml(), $cacheId);
+            $this->_saveCache($result->asXML(), $cacheId);
         }
         $this->layoutUpdatesCache = $result;
         return $result;
diff --git a/lib/internal/Magento/Framework/View/Page/Config/Reader/Head.php b/lib/internal/Magento/Framework/View/Page/Config/Reader/Head.php
index 8328f03fd6db5..71a2951b40420 100644
--- a/lib/internal/Magento/Framework/View/Page/Config/Reader/Head.php
+++ b/lib/internal/Magento/Framework/View/Page/Config/Reader/Head.php
@@ -138,6 +138,6 @@ private function setMetadata($pageConfigStructure, $node)
             $metadataName = $node->getAttribute('name');
         }
 
-        $pageConfigStructure->setMetaData($metadataName, $node->getAttribute('content'));
+        $pageConfigStructure->setMetadata($metadataName, $node->getAttribute('content'));
     }
 }
diff --git a/lib/internal/Magento/Framework/View/Test/Unit/Element/Html/Link/CurrentTest.php b/lib/internal/Magento/Framework/View/Test/Unit/Element/Html/Link/CurrentTest.php
index 4515a29c65e4f..909748722a081 100644
--- a/lib/internal/Magento/Framework/View/Test/Unit/Element/Html/Link/CurrentTest.php
+++ b/lib/internal/Magento/Framework/View/Test/Unit/Element/Html/Link/CurrentTest.php
@@ -57,7 +57,7 @@ public function testIsCurrentIfIsset()
         /** @var \Magento\Framework\View\Element\Html\Link\Current $link */
         $link = $this->_objectManager->getObject(\Magento\Framework\View\Element\Html\Link\Current::class);
         $link->setCurrent(true);
-        $this->assertTrue($link->IsCurrent());
+        $this->assertTrue($link->isCurrent());
     }
 
     public function testIsCurrent()
diff --git a/lib/internal/Magento/Framework/View/Test/Unit/LayoutTest.php b/lib/internal/Magento/Framework/View/Test/Unit/LayoutTest.php
index c0300164e26fe..f8a8939bbfe36 100755
--- a/lib/internal/Magento/Framework/View/Test/Unit/LayoutTest.php
+++ b/lib/internal/Magento/Framework/View/Test/Unit/LayoutTest.php
@@ -273,7 +273,7 @@ public function testGenerateXml()
             ->with($this->equalTo([]))
             ->will($this->returnSelf());
         $this->assertSame($this->model, $this->model->generateXml());
-        $this->assertSame('<some_update>123</some_update>', $this->model->getNode('some_update')->asXml());
+        $this->assertSame('<some_update>123</some_update>', $this->model->getNode('some_update')->asXML());
     }
 
     public function testGetChildBlock()
diff --git a/setup/src/Magento/Setup/Model/PhpReadinessCheck.php b/setup/src/Magento/Setup/Model/PhpReadinessCheck.php
index c2bdafa8df82e..2c4967c4c2ffd 100644
--- a/setup/src/Magento/Setup/Model/PhpReadinessCheck.php
+++ b/setup/src/Magento/Setup/Model/PhpReadinessCheck.php
@@ -286,7 +286,7 @@ private function checkPopulateRawPostSetting()
 
         $data = [];
         $error = false;
-        $iniSetting = intVal(ini_get('always_populate_raw_post_data'));
+        $iniSetting = intval(ini_get('always_populate_raw_post_data'));
 
         $checkVersionConstraint = $this->versionParser->parseConstraints('~5.6.0');
         $normalizedPhpVersion = $this->getNormalizedCurrentPhpVersion(PHP_VERSION);
@@ -302,7 +302,7 @@ private function checkPopulateRawPostSetting()
 	        Please open your php.ini file and set always_populate_raw_post_data to -1.
  	        If you need more help please call your hosting provider.',
             PHP_VERSION,
-            intVal(ini_get('always_populate_raw_post_data'))
+            intval(ini_get('always_populate_raw_post_data'))
         );
 
         $data['always_populate_raw_post_data'] = [