diff --git a/app/code/Magento/AdvancedPricingImportExport/Model/Import/AdvancedPricing.php b/app/code/Magento/AdvancedPricingImportExport/Model/Import/AdvancedPricing.php
index 23829d3725119..0e8acb37104e6 100644
--- a/app/code/Magento/AdvancedPricingImportExport/Model/Import/AdvancedPricing.php
+++ b/app/code/Magento/AdvancedPricingImportExport/Model/Import/AdvancedPricing.php
@@ -394,7 +394,7 @@ protected function saveAndReplaceAdvancedPrices()
                             ? $rowData[self::COL_TIER_PRICE] : 0,
                         'percentage_value' => $rowData[self::COL_TIER_PRICE_TYPE] === self::TIER_PRICE_TYPE_PERCENT
                             ? $rowData[self::COL_TIER_PRICE] : null,
-                        'website_id' => $this->getWebsiteId($rowData[self::COL_TIER_PRICE_WEBSITE])
+                        'website_id' => $this->getWebSiteId($rowData[self::COL_TIER_PRICE_WEBSITE])
                     ];
                 }
             }
diff --git a/app/code/Magento/AdvancedPricingImportExport/Test/Unit/Model/Import/AdvancedPricing/Validator/WebsiteTest.php b/app/code/Magento/AdvancedPricingImportExport/Test/Unit/Model/Import/AdvancedPricing/Validator/WebsiteTest.php
index 5111b4932d7a8..9a380ff75da24 100644
--- a/app/code/Magento/AdvancedPricingImportExport/Test/Unit/Model/Import/AdvancedPricing/Validator/WebsiteTest.php
+++ b/app/code/Magento/AdvancedPricingImportExport/Test/Unit/Model/Import/AdvancedPricing/Validator/WebsiteTest.php
@@ -27,7 +27,7 @@ class WebsiteTest extends \PHPUnit\Framework\TestCase
 
     protected function setUp()
     {
-        $this->webSiteModel = $this->getMockBuilder(\Magento\Store\Model\WebSite::class)
+        $this->webSiteModel = $this->getMockBuilder(\Magento\Store\Model\Website::class)
             ->setMethods(['getBaseCurrency'])
             ->disableOriginalConstructor()
             ->getMock();
diff --git a/app/code/Magento/Backend/Block/System/Store/Edit/AbstractForm.php b/app/code/Magento/Backend/Block/System/Store/Edit/AbstractForm.php
index f19799d2e4939..034887c67d1ee 100644
--- a/app/code/Magento/Backend/Block/System/Store/Edit/AbstractForm.php
+++ b/app/code/Magento/Backend/Block/System/Store/Edit/AbstractForm.php
@@ -37,7 +37,7 @@ protected function _prepareForm()
             ['data' => ['id' => 'edit_form', 'action' => $this->getData('action'), 'method' => 'post']]
         );
 
-        $this->_prepareStoreFieldSet($form);
+        $this->_prepareStoreFieldset($form);
 
         $form->addField(
             'store_type',
diff --git a/app/code/Magento/Backend/Controller/Adminhtml/System/Account/Save.php b/app/code/Magento/Backend/Controller/Adminhtml/System/Account/Save.php
index c9bce1cbf3888..421885a0c32a3 100644
--- a/app/code/Magento/Backend/Controller/Adminhtml/System/Account/Save.php
+++ b/app/code/Magento/Backend/Controller/Adminhtml/System/Account/Save.php
@@ -54,9 +54,9 @@ public function execute()
         $user = $this->_objectManager->create(\Magento\User\Model\User::class)->load($userId);
 
         $user->setId($userId)
-            ->setUsername($this->getRequest()->getParam('username', false))
-            ->setFirstname($this->getRequest()->getParam('firstname', false))
-            ->setLastname($this->getRequest()->getParam('lastname', false))
+            ->setUserName($this->getRequest()->getParam('username', false))
+            ->setFirstName($this->getRequest()->getParam('firstname', false))
+            ->setLastName($this->getRequest()->getParam('lastname', false))
             ->setEmail(strtolower($this->getRequest()->getParam('email', false)));
 
         if ($this->_objectManager->get(\Magento\Framework\Validator\Locale::class)->isValid($interfaceLocale)) {
diff --git a/app/code/Magento/Backend/Test/Unit/Block/Widget/Grid/ColumnSetTest.php b/app/code/Magento/Backend/Test/Unit/Block/Widget/Grid/ColumnSetTest.php
index be171a8ed40bf..df242a4cf6129 100644
--- a/app/code/Magento/Backend/Test/Unit/Block/Widget/Grid/ColumnSetTest.php
+++ b/app/code/Magento/Backend/Test/Unit/Block/Widget/Grid/ColumnSetTest.php
@@ -117,7 +117,7 @@ public function testSetFilterTypePropagatesFilterTypeToColumns()
 
     public function testGetRowUrlIfUrlPathNotSet()
     {
-        $this->assertEquals('#', $this->_block->getRowUrl(new \StdClass()));
+        $this->assertEquals('#', $this->_block->getRowUrl(new \stdClass()));
     }
 
     public function testGetRowUrl()
diff --git a/app/code/Magento/Backend/Test/Unit/Block/Widget/Grid/ColumnTest.php b/app/code/Magento/Backend/Test/Unit/Block/Widget/Grid/ColumnTest.php
index da13af87b71ea..c5c56fd75fbe7 100644
--- a/app/code/Magento/Backend/Test/Unit/Block/Widget/Grid/ColumnTest.php
+++ b/app/code/Magento/Backend/Test/Unit/Block/Widget/Grid/ColumnTest.php
@@ -351,7 +351,7 @@ public function testSetGetGrid()
 
         $this->_block->setFilter('StdClass');
 
-        $grid = new \StdClass();
+        $grid = new \stdClass();
         $this->_block->setGrid($grid);
         $this->assertEquals($grid, $this->_block->getGrid());
     }
diff --git a/app/code/Magento/Backend/view/adminhtml/templates/page/header.phtml b/app/code/Magento/Backend/view/adminhtml/templates/page/header.phtml
index 40b7173f47417..8feccc9cf1b8f 100644
--- a/app/code/Magento/Backend/view/adminhtml/templates/page/header.phtml
+++ b/app/code/Magento/Backend/view/adminhtml/templates/page/header.phtml
@@ -29,7 +29,7 @@
                 data-mage-init='{"dropdown":{}}'
                 data-toggle="dropdown">
                 <span class="admin__action-dropdown-text">
-                    <span class="admin-user-account-text"><?= $block->escapeHtml($block->getUser()->getUsername()) ?></span>
+                    <span class="admin-user-account-text"><?= $block->escapeHtml($block->getUser()->getUserName()) ?></span>
                 </span>
             </a>
             <ul class="admin__action-dropdown-menu">
@@ -39,7 +39,7 @@
                         href="<?= /* @escapeNotVerified */ $block->getUrl('adminhtml/system_account/index') ?>"
                         <?= /* @escapeNotVerified */ $block->getUiId('user', 'account', 'settings') ?>
                         title="<?= $block->escapeHtml(__('Account Setting')) ?>">
-                        <?= /* @escapeNotVerified */ __('Account Setting') ?> (<span class="admin-user-name"><?= $block->escapeHtml($block->getUser()->getUsername()) ?></span>)
+                        <?= /* @escapeNotVerified */ __('Account Setting') ?> (<span class="admin-user-name"><?= $block->escapeHtml($block->getUser()->getUserName()) ?></span>)
                     </a>
                 </li>
                 <?php endif; ?>
diff --git a/app/code/Magento/Backend/view/adminhtml/templates/system/search.phtml b/app/code/Magento/Backend/view/adminhtml/templates/system/search.phtml
index a528133b2bc3a..b50183ced29b4 100644
--- a/app/code/Magento/Backend/view/adminhtml/templates/system/search.phtml
+++ b/app/code/Magento/Backend/view/adminhtml/templates/system/search.phtml
@@ -28,16 +28,16 @@
     <script data-template="search-suggest" type="text/x-magento-template">
         <ul class="search-global-menu">
         <li class="item">
-            <a id="searchPreviewProducts" href="<?= /* @escapeNotVerified */ $block->getURL('catalog/product/index/') ?>?search=<%- data.term%>" class="title">"<%- data.term%>" in Products</a>
+            <a id="searchPreviewProducts" href="<?= /* @escapeNotVerified */ $block->getUrl('catalog/product/index/') ?>?search=<%- data.term%>" class="title">"<%- data.term%>" in Products</a>
         </li>
         <li class="item">
-            <a id="searchPreviewOrders" href="<?= /* @escapeNotVerified */ $block->getURL('sales/order/index/') ?>?search=<%- data.term%>" class="title">"<%- data.term%>" in Orders</a>
+            <a id="searchPreviewOrders" href="<?= /* @escapeNotVerified */ $block->getUrl('sales/order/index/') ?>?search=<%- data.term%>" class="title">"<%- data.term%>" in Orders</a>
         </li>
         <li class="item">
-            <a id="searchPreviewCustomers" href="<?= /* @escapeNotVerified */ $block->getURL('customer/index/index/') ?>?search=<%- data.term%>" class="title">"<%- data.term%>" in Customers</a>
+            <a id="searchPreviewCustomers" href="<?= /* @escapeNotVerified */ $block->getUrl('customer/index/index/') ?>?search=<%- data.term%>" class="title">"<%- data.term%>" in Customers</a>
         </li>
         <li class="item">
-            <a id="searchPreviewPages" href="<?= /* @escapeNotVerified */ $block->getURL('cms/page/index/') ?>?search=<%- data.term%>" class="title">"<%- data.term%>" in Pages</a>
+            <a id="searchPreviewPages" href="<?= /* @escapeNotVerified */ $block->getUrl('cms/page/index/') ?>?search=<%- data.term%>" class="title">"<%- data.term%>" in Pages</a>
         </li>
             <% if (data.items.length) { %>
             <% _.each(data.items, function(value){ %>
diff --git a/app/code/Magento/Backend/view/adminhtml/templates/widget/grid/extended.phtml b/app/code/Magento/Backend/view/adminhtml/templates/widget/grid/extended.phtml
index a31bf4d23abaa..f97db4ad993b1 100644
--- a/app/code/Magento/Backend/view/adminhtml/templates/widget/grid/extended.phtml
+++ b/app/code/Magento/Backend/view/adminhtml/templates/widget/grid/extended.phtml
@@ -72,7 +72,7 @@ $numColumns = sizeof($block->getColumns());
             <?php if ($block->getPagerVisibility()): ?>
                 <div class="admin__data-grid-pager-wrap">
                     <select name="<?= /* @escapeNotVerified */ $block->getVarNameLimit() ?>"
-                            id="<?= $block->escapeHTML($block->getHtmlId()) ?>_page-limit"
+                            id="<?= $block->escapeHtml($block->getHtmlId()) ?>_page-limit"
                             onchange="<?= /* @escapeNotVerified */ $block->getJsObjectName() ?>.loadByElement(this)"
                             class="admin__control-select">
                         <option value="20"<?php if ($block->getCollection()->getPageSize() == 20): ?>
@@ -91,7 +91,7 @@ $numColumns = sizeof($block->getColumns());
                             selected="selected"<?php endif; ?>>200
                         </option>
                     </select>
-                    <label for="<?= $block->escapeHTML($block->getHtmlId()) ?><?= $block->escapeHTML($block->getHtmlId()) ?>_page-limit"
+                    <label for="<?= $block->escapeHtml($block->getHtmlId()) ?><?= $block->escapeHtml($block->getHtmlId()) ?>_page-limit"
                         class="admin__control-support-text"><?= /* @escapeNotVerified */ __('per page') ?></label>
 
                     <div class="admin__data-grid-pager">
@@ -107,12 +107,12 @@ $numColumns = sizeof($block->getColumns());
                             <button type="button" class="action-previous disabled"><span><?= /* @escapeNotVerified */ __('Previous page') ?></span></button>
                         <?php endif; ?>
                         <input type="text"
-                               id="<?= $block->escapeHTML($block->getHtmlId()) ?>_page-current"
+                               id="<?= $block->escapeHtml($block->getHtmlId()) ?>_page-current"
                                name="<?= /* @escapeNotVerified */ $block->getVarNamePage() ?>"
                                value="<?= /* @escapeNotVerified */ $_curPage ?>"
                                class="admin__control-text"
                                onkeypress="<?= /* @escapeNotVerified */ $block->getJsObjectName() ?>.inputPage(event, '<?= /* @escapeNotVerified */ $_lastPage ?>')" <?= /* @escapeNotVerified */ $block->getUiId('current-page') ?> />
-                        <label class="admin__control-support-text" for="<?= $block->escapeHTML($block->getHtmlId()) ?>_page-current">
+                        <label class="admin__control-support-text" for="<?= $block->escapeHtml($block->getHtmlId()) ?>_page-current">
                             <?= /* @escapeNotVerified */ __('of %1', '<span>' . $block->getCollection()->getLastPageNumber() . '</span>') ?>
                         </label>
                         <?php if ($_curPage < $_lastPage): ?>
diff --git a/app/code/Magento/Catalog/Block/Product/View/Options/Type/Select.php b/app/code/Magento/Catalog/Block/Product/View/Options/Type/Select.php
index d546ef483132b..7df9b972e1501 100644
--- a/app/code/Magento/Catalog/Block/Product/View/Options/Type/Select.php
+++ b/app/code/Magento/Catalog/Block/Product/View/Options/Type/Select.php
@@ -44,9 +44,9 @@ public function getValuesHtml()
                 ]
             );
             if ($_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_DROP_DOWN) {
-                $select->setName('options[' . $_option->getid() . ']')->addOption('', __('-- Please Select --'));
+                $select->setName('options[' . $_option->getId() . ']')->addOption('', __('-- Please Select --'));
             } else {
-                $select->setName('options[' . $_option->getid() . '][]');
+                $select->setName('options[' . $_option->getId() . '][]');
                 $select->setClass('multiselect admin__control-multiselect' . $require . ' product-custom-option');
             }
             foreach ($_option->getValues() as $_value) {
diff --git a/app/code/Magento/Catalog/Test/Unit/Model/Product/Attribute/Backend/GroupPrice/AbstractTest.php b/app/code/Magento/Catalog/Test/Unit/Model/Product/Attribute/Backend/GroupPrice/AbstractTest.php
index 5963d8b161633..3003c2f8085e4 100644
--- a/app/code/Magento/Catalog/Test/Unit/Model/Product/Attribute/Backend/GroupPrice/AbstractTest.php
+++ b/app/code/Magento/Catalog/Test/Unit/Model/Product/Attribute/Backend/GroupPrice/AbstractTest.php
@@ -47,7 +47,7 @@ protected function setUp()
                 'scopeOverriddenValue' => $scopeOverriddenValue
             ]
         );
-        $resource = $this->createPartialMock(\StdClass::class, ['getMainTable']);
+        $resource = $this->createPartialMock(\stdClass::class, ['getMainTable']);
         $resource->expects($this->any())->method('getMainTable')->will($this->returnValue('table'));
 
         $this->_model->expects($this->any())->method('_getResource')->will($this->returnValue($resource));
diff --git a/app/code/Magento/Catalog/view/adminhtml/templates/catalog/product/tab/inventory.phtml b/app/code/Magento/Catalog/view/adminhtml/templates/catalog/product/tab/inventory.phtml
index 15c33c56e3ac6..2c62bbf8db3e9 100644
--- a/app/code/Magento/Catalog/view/adminhtml/templates/catalog/product/tab/inventory.phtml
+++ b/app/code/Magento/Catalog/view/adminhtml/templates/catalog/product/tab/inventory.phtml
@@ -27,7 +27,7 @@
             <option value="0"<?php if ($block->getFieldValue('manage_stock') == 0): ?> selected="selected"<?php endif; ?>><?= /* @escapeNotVerified */ __('No') ?></option>
         </select>
         <input type="hidden" id="inventory_manage_stock_default" value="<?= /* @escapeNotVerified */ $block->getDefaultConfigValue('manage_stock') ?>">
-        <?php $_checked = ($block->getFieldValue('use_config_manage_stock') || $block->IsNew()) ? 'checked="checked"' : '' ?>
+        <?php $_checked = ($block->getFieldValue('use_config_manage_stock') || $block->isNew()) ? 'checked="checked"' : '' ?>
         <input type="checkbox" id="inventory_use_config_manage_stock" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][use_config_manage_stock]" value="1" <?= /* @escapeNotVerified */ $_checked ?> onclick="toggleValueElements(this, this.parentNode);" <?= /* @escapeNotVerified */ $_readonly ?>>
         <label for="inventory_use_config_manage_stock"><?= /* @escapeNotVerified */ __('Use Config Settings') ?></label>
         <?php if (!$block->isReadonly()): ?>
@@ -67,7 +67,7 @@ toggleValueElements($('inventory_use_config_manage_stock'), $('inventory_use_con
         <input type="text" class="input-text validate-number" id="inventory_min_qty" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][min_qty]" value="<?= /* @escapeNotVerified */ $block->getFieldValue('min_qty') * 1 ?>" <?= /* @escapeNotVerified */ $_readonly ?>>
 
         <div class="control-inner-wrap">
-            <?php $_checked = ($block->getFieldValue('use_config_min_qty') || $block->IsNew()) ? 'checked="checked"' : '' ?>
+            <?php $_checked = ($block->getFieldValue('use_config_min_qty') || $block->isNew()) ? 'checked="checked"' : '' ?>
             <input type="checkbox" id="inventory_use_config_min_qty" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][use_config_min_qty]" value="1" <?= /* @escapeNotVerified */ $_checked ?> onclick="toggleValueElements(this, this.parentNode);" <?= /* @escapeNotVerified */ $_readonly ?>>
             <label for="inventory_use_config_min_qty"><?= /* @escapeNotVerified */ __('Use Config Settings') ?></label>
         </div>
@@ -94,7 +94,7 @@ toggleValueElements($('inventory_use_config_min_qty'), $('inventory_use_config_m
                name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][min_sale_qty]"
                value="<?= /* @escapeNotVerified */ $block->getFieldValue('min_sale_qty') * 1 ?>" <?= /* @escapeNotVerified */ $_readonly ?>>
         <div class="control-inner-wrap">
-        <?php $_checked = ($block->getFieldValue('use_config_min_sale_qty') || $block->IsNew()) ? 'checked="checked"' : '' ?>
+        <?php $_checked = ($block->getFieldValue('use_config_min_sale_qty') || $block->isNew()) ? 'checked="checked"' : '' ?>
             <input type="checkbox" id="inventory_use_config_min_sale_qty" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][use_config_min_sale_qty]" value="1" <?= /* @escapeNotVerified */ $_checked ?> onclick="toggleValueElements(this, this.parentNode);" class="checkbox" <?= /* @escapeNotVerified */ $_readonly ?>>
             <label for="inventory_use_config_min_sale_qty"><?= /* @escapeNotVerified */ __('Use Config Settings') ?></label>
         </div>
@@ -117,7 +117,7 @@ toggleValueElements($('inventory_use_config_min_sale_qty'), $('inventory_use_con
     </label>
     <div class="control">
         <input type="text" class="input-text validate-number" id="inventory_max_sale_qty" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][max_sale_qty]" value="<?= /* @escapeNotVerified */ $block->getFieldValue('max_sale_qty') * 1 ?>" <?= /* @escapeNotVerified */ $_readonly ?>>
-        <?php $_checked = ($block->getFieldValue('use_config_max_sale_qty') || $block->IsNew()) ? 'checked="checked"' : '' ?>
+        <?php $_checked = ($block->getFieldValue('use_config_max_sale_qty') || $block->isNew()) ? 'checked="checked"' : '' ?>
         <div class="control-inner-wrap">
             <input type="checkbox" id="inventory_use_config_max_sale_qty" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][use_config_max_sale_qty]" value="1" <?= /* @escapeNotVerified */ $_checked ?> onclick="toggleValueElements(this, this.parentNode);" class="checkbox" <?= /* @escapeNotVerified */ $_readonly ?>>
             <label for="inventory_use_config_max_sale_qty"><?= /* @escapeNotVerified */ __('Use Config Settings') ?></label>
@@ -182,7 +182,7 @@ toggleValueElements($('inventory_use_config_max_sale_qty'), $('inventory_use_con
         </select>
 
         <div class="control-inner-wrap">
-            <?php $_checked = ($block->getFieldValue('use_config_backorders') || $block->IsNew()) ? 'checked="checked"' : '' ?>
+            <?php $_checked = ($block->getFieldValue('use_config_backorders') || $block->isNew()) ? 'checked="checked"' : '' ?>
             <input type="checkbox" id="inventory_use_config_backorders" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][use_config_backorders]" value="1" <?= /* @escapeNotVerified */ $_checked ?> onclick="toggleValueElements(this, this.parentNode);" <?= /* @escapeNotVerified */ $_readonly ?>>
             <label for="inventory_use_config_backorders"><?= /* @escapeNotVerified */ __('Use Config Settings') ?></label>
         </div>
@@ -207,7 +207,7 @@ toggleValueElements($('inventory_use_config_backorders'), $('inventory_use_confi
         <input type="text" class="input-text validate-number" id="inventory_notify_stock_qty" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][notify_stock_qty]" value="<?= /* @escapeNotVerified */ $block->getFieldValue('notify_stock_qty') * 1 ?>" <?= /* @escapeNotVerified */ $_readonly ?>>
 
         <div class="control-inner-wrap">
-            <?php $_checked = ($block->getFieldValue('use_config_notify_stock_qty') || $block->IsNew()) ? 'checked="checked"' : '' ?>
+            <?php $_checked = ($block->getFieldValue('use_config_notify_stock_qty') || $block->isNew()) ? 'checked="checked"' : '' ?>
             <input type="checkbox" id="inventory_use_config_notify_stock_qty" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][use_config_notify_stock_qty]" value="1" <?= /* @escapeNotVerified */ $_checked ?> onclick="toggleValueElements(this, this.parentNode);" <?= /* @escapeNotVerified */ $_readonly ?>>
             <label for="inventory_use_config_notify_stock_qty"><?= /* @escapeNotVerified */ __('Use Config Settings') ?></label>
         </div>
@@ -238,7 +238,7 @@ toggleValueElements($('inventory_use_config_notify_stock_qty'), $('inventory_use
         <input type="hidden" id="inventory_enable_qty_increments_default" value="<?= /* @escapeNotVerified */ $block->getDefaultConfigValue('enable_qty_increments') ?>">
 
         <div class="control-inner-wrap">
-            <?php $_checked = ($block->getFieldValue('use_config_enable_qty_inc') || $block->IsNew()) ? 'checked="checked"' : '' ?>
+            <?php $_checked = ($block->getFieldValue('use_config_enable_qty_inc') || $block->isNew()) ? 'checked="checked"' : '' ?>
             <input type="checkbox" id="inventory_use_config_enable_qty_increments" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][use_config_enable_qty_increments]" value="1" <?= /* @escapeNotVerified */ $_checked ?> onclick="toggleValueElements(this, this.parentNode);" <?= /* @escapeNotVerified */ $_readonly ?>>
             <label for="inventory_use_config_enable_qty_increments"><?= /* @escapeNotVerified */ __('Use Config Settings') ?></label>
         </div>
@@ -262,7 +262,7 @@ toggleValueElements($('inventory_use_config_enable_qty_increments'), $('inventor
     <div class="control">
         <input type="text" class="input-text validate-digits" id="inventory_qty_increments" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][qty_increments]" value="<?= /* @escapeNotVerified */ $block->getFieldValue('qty_increments') * 1 ?>" <?= /* @escapeNotVerified */ $_readonly ?>>
         <div class="control-inner-wrap">
-            <?php $_checked = ($block->getFieldValue('use_config_qty_increments') || $block->IsNew()) ? 'checked="checked"' : '' ?>
+            <?php $_checked = ($block->getFieldValue('use_config_qty_increments') || $block->isNew()) ? 'checked="checked"' : '' ?>
             <input type="checkbox" id="inventory_use_config_qty_increments" name="<?= /* @escapeNotVerified */ $block->getFieldSuffix() ?>[stock_data][use_config_qty_increments]" value="1" <?= /* @escapeNotVerified */ $_checked ?> onclick="toggleValueElements(this, this.parentNode);" <?= /* @escapeNotVerified */ $_readonly ?>>
             <label for="inventory_use_config_qty_increments"><?= /* @escapeNotVerified */ __('Use Config Settings') ?></label>
         </div>
diff --git a/app/code/Magento/Cms/Helper/Wysiwyg/Images.php b/app/code/Magento/Cms/Helper/Wysiwyg/Images.php
index a557e045c5ef2..d8a43d92f6d44 100644
--- a/app/code/Magento/Cms/Helper/Wysiwyg/Images.php
+++ b/app/code/Magento/Cms/Helper/Wysiwyg/Images.php
@@ -148,7 +148,7 @@ public function convertIdToPath($id)
      */
     public function isUsingStaticUrlsAllowed()
     {
-        $checkResult = new \StdClass();
+        $checkResult = new \stdClass();
         $checkResult->isAllowed = false;
         $this->_eventManager->dispatch(
             'cms_wysiwyg_images_static_urls_allowed',
diff --git a/app/code/Magento/Cms/Test/Unit/Helper/Wysiwyg/ImagesTest.php b/app/code/Magento/Cms/Test/Unit/Helper/Wysiwyg/ImagesTest.php
index 05dad459f064e..67401797502ce 100644
--- a/app/code/Magento/Cms/Test/Unit/Helper/Wysiwyg/ImagesTest.php
+++ b/app/code/Magento/Cms/Test/Unit/Helper/Wysiwyg/ImagesTest.php
@@ -293,7 +293,7 @@ protected function generalSettingsIsUsingStaticUrlsAllowed($allowedValue)
     {
         $storeId = 1;
         $this->imagesHelper->setStoreId($storeId);
-        $checkResult = new \StdClass();
+        $checkResult = new \stdClass();
         $checkResult->isAllowed = false;
         $this->eventManagerMock->expects($this->any())
             ->method('dispatch')
diff --git a/app/code/Magento/Config/Test/Unit/Model/Config/Structure/ElementVisibilityCompositeTest.php b/app/code/Magento/Config/Test/Unit/Model/Config/Structure/ElementVisibilityCompositeTest.php
index a3bdb6f008f1d..b779c29c93155 100644
--- a/app/code/Magento/Config/Test/Unit/Model/Config/Structure/ElementVisibilityCompositeTest.php
+++ b/app/code/Magento/Config/Test/Unit/Model/Config/Structure/ElementVisibilityCompositeTest.php
@@ -44,7 +44,7 @@ protected function setUp()
     public function testException()
     {
         $visibility = [
-            'stdClass' => new \StdClass()
+            'stdClass' => new \stdClass()
         ];
 
         new ElementVisibilityComposite($visibility);
diff --git a/app/code/Magento/ConfigurableProduct/Test/Unit/Model/Product/Cache/Tag/ConfigurableTest.php b/app/code/Magento/ConfigurableProduct/Test/Unit/Model/Product/Cache/Tag/ConfigurableTest.php
index 519288a50c858..5b4a8d5b8a975 100644
--- a/app/code/Magento/ConfigurableProduct/Test/Unit/Model/Product/Cache/Tag/ConfigurableTest.php
+++ b/app/code/Magento/ConfigurableProduct/Test/Unit/Model/Product/Cache/Tag/ConfigurableTest.php
@@ -39,7 +39,7 @@ public function testGetWithScalar()
     public function testGetTagsWithObject()
     {
         $this->expectException(\InvalidArgumentException::class, 'Provided argument must be a product');
-        $this->model->getTags(new \StdClass());
+        $this->model->getTags(new \stdClass());
     }
 
     public function testGetTagsWithVariation()
diff --git a/app/code/Magento/Customer/Block/Adminhtml/Edit/Tab/Newsletter.php b/app/code/Magento/Customer/Block/Adminhtml/Edit/Tab/Newsletter.php
index 8506defbf9005..032d1ae5d732f 100644
--- a/app/code/Magento/Customer/Block/Adminhtml/Edit/Tab/Newsletter.php
+++ b/app/code/Magento/Customer/Block/Adminhtml/Edit/Tab/Newsletter.php
@@ -160,7 +160,7 @@ public function initForm()
             ]
         );
 
-        if ($this->customerAccountManagement->isReadOnly($customerId)) {
+        if ($this->customerAccountManagement->isReadonly($customerId)) {
             $form->getElement('subscription')->setReadonly(true, true);
         }
         $isSubscribed = $subscriber->isSubscribed();
diff --git a/app/code/Magento/Deploy/Test/Unit/Model/DeploymentConfig/ImporterFactoryTest.php b/app/code/Magento/Deploy/Test/Unit/Model/DeploymentConfig/ImporterFactoryTest.php
index c9e101ed3a9e8..8a0284eb4f775 100644
--- a/app/code/Magento/Deploy/Test/Unit/Model/DeploymentConfig/ImporterFactoryTest.php
+++ b/app/code/Magento/Deploy/Test/Unit/Model/DeploymentConfig/ImporterFactoryTest.php
@@ -55,7 +55,7 @@ public function testCreateWithInvalidArgumentException()
         $className = 'some/class/name';
 
         /** @var \StdClass|\PHPUnit_Framework_MockObject_MockObject $importerMock */
-        $importerMock = $this->getMockBuilder(\StdClass::class)
+        $importerMock = $this->getMockBuilder(\stdClass::class)
             ->disableOriginalConstructor()
             ->getMock();
 
diff --git a/app/code/Magento/Deploy/Test/Unit/Model/DeploymentConfig/ValidatorFactoryTest.php b/app/code/Magento/Deploy/Test/Unit/Model/DeploymentConfig/ValidatorFactoryTest.php
index 1da524b37ca15..50960808781ab 100644
--- a/app/code/Magento/Deploy/Test/Unit/Model/DeploymentConfig/ValidatorFactoryTest.php
+++ b/app/code/Magento/Deploy/Test/Unit/Model/DeploymentConfig/ValidatorFactoryTest.php
@@ -56,7 +56,7 @@ public function testCreateWrongImplementation()
     {
         $className = 'className';
 
-        $stdMock = $this->getMockBuilder(\StdClass::class)
+        $stdMock = $this->getMockBuilder(\stdClass::class)
             ->disableOriginalConstructor()
             ->getMock();
         $this->objectManagerMock->expects($this->once())
diff --git a/app/code/Magento/Downloadable/Model/LinkRepository.php b/app/code/Magento/Downloadable/Model/LinkRepository.php
index 65239ad353c3f..b84a8284c9083 100644
--- a/app/code/Magento/Downloadable/Model/LinkRepository.php
+++ b/app/code/Magento/Downloadable/Model/LinkRepository.php
@@ -207,7 +207,7 @@ protected function saveLink(
         $isGlobalScopeContent
     ) {
         $linkData = [
-            'link_id' => (int)$link->getid(),
+            'link_id' => (int)$link->getId(),
             'is_delete' => 0,
             'type' => $link->getLinkType(),
             'sort_order' => $link->getSortOrder(),
diff --git a/app/code/Magento/Downloadable/Model/SampleRepository.php b/app/code/Magento/Downloadable/Model/SampleRepository.php
index 633243ac2eb86..5b9e8e784b9f3 100644
--- a/app/code/Magento/Downloadable/Model/SampleRepository.php
+++ b/app/code/Magento/Downloadable/Model/SampleRepository.php
@@ -215,7 +215,7 @@ protected function saveSample(
         $isGlobalScopeContent
     ) {
         $sampleData = [
-            'sample_id' => (int)$sample->getid(),
+            'sample_id' => (int)$sample->getId(),
             'is_delete' => 0,
             'type' => $sample->getSampleType(),
             'sort_order' => $sample->getSortOrder(),
diff --git a/app/code/Magento/Downloadable/Test/Unit/Ui/DataProvider/Product/Form/Modifier/CompositeTest.php b/app/code/Magento/Downloadable/Test/Unit/Ui/DataProvider/Product/Form/Modifier/CompositeTest.php
index 155f95874eeeb..5b04c83f4ffb7 100644
--- a/app/code/Magento/Downloadable/Test/Unit/Ui/DataProvider/Product/Form/Modifier/CompositeTest.php
+++ b/app/code/Magento/Downloadable/Test/Unit/Ui/DataProvider/Product/Form/Modifier/CompositeTest.php
@@ -156,7 +156,7 @@ protected function canShowDownloadablePanel($typeId)
      */
     protected function initModifiers()
     {
-        $this->modifierMock = $this->getMockBuilder(\StdClass::class)
+        $this->modifierMock = $this->getMockBuilder(\stdClass::class)
             ->setMethods(['modifyData', 'modifyMeta'])
             ->getMock();
         $this->modifierFactoryMock->expects($this->once())
diff --git a/app/code/Magento/Eav/Model/Entity/AbstractEntity.php b/app/code/Magento/Eav/Model/Entity/AbstractEntity.php
index 105bc0a0becf5..0c74b84457d40 100644
--- a/app/code/Magento/Eav/Model/Entity/AbstractEntity.php
+++ b/app/code/Magento/Eav/Model/Entity/AbstractEntity.php
@@ -1656,7 +1656,7 @@ public function saveAttribute(\Magento\Framework\DataObject $object, $attributeC
             $this->_processAttributeValues();
             $connection->commit();
         } catch (\Exception $e) {
-            $connection->rollback();
+            $connection->rollBack();
             throw $e;
         }
 
diff --git a/app/code/Magento/Email/Test/Unit/Block/Adminhtml/Template/EditTest.php b/app/code/Magento/Email/Test/Unit/Block/Adminhtml/Template/EditTest.php
index aa531e8189cea..9a333e2d01a88 100644
--- a/app/code/Magento/Email/Test/Unit/Block/Adminhtml/Template/EditTest.php
+++ b/app/code/Magento/Email/Test/Unit/Block/Adminhtml/Template/EditTest.php
@@ -66,7 +66,7 @@ protected function setUp()
             ['getFilesystem', '__wakeup', 'getPath', 'getDirectoryRead']
         );
 
-        $viewFilesystem = $this->getMockBuilder(\Magento\Framework\View\Filesystem::class)
+        $viewFilesystem = $this->getMockBuilder(\Magento\Framework\View\FileSystem::class)
             ->setMethods(['getTemplateFileName'])
             ->disableOriginalConstructor()
             ->getMock();
diff --git a/app/code/Magento/NewRelicReporting/Model/Observer/ReportConcurrentAdmins.php b/app/code/Magento/NewRelicReporting/Model/Observer/ReportConcurrentAdmins.php
index 615c80633cb0f..9dfd0e1e3319a 100644
--- a/app/code/Magento/NewRelicReporting/Model/Observer/ReportConcurrentAdmins.php
+++ b/app/code/Magento/NewRelicReporting/Model/Observer/ReportConcurrentAdmins.php
@@ -66,8 +66,8 @@ public function execute(Observer $observer)
                 $user = $this->backendAuthSession->getUser();
                 $jsonData = [
                     'id' => $user->getId(),
-                    'username' => $user->getUsername(),
-                    'name' => $user->getFirstname() . ' ' . $user->getLastname(),
+                    'username' => $user->getUserName(),
+                    'name' => $user->getFirstName() . ' ' . $user->getLastName(),
                 ];
 
                 $modelData = [
diff --git a/app/code/Magento/NewRelicReporting/Model/Observer/ReportConcurrentAdminsToNewRelic.php b/app/code/Magento/NewRelicReporting/Model/Observer/ReportConcurrentAdminsToNewRelic.php
index cff1b159d481d..2f142f6ac8124 100644
--- a/app/code/Magento/NewRelicReporting/Model/Observer/ReportConcurrentAdminsToNewRelic.php
+++ b/app/code/Magento/NewRelicReporting/Model/Observer/ReportConcurrentAdminsToNewRelic.php
@@ -58,10 +58,10 @@ public function execute(Observer $observer)
             if ($this->backendAuthSession->isLoggedIn()) {
                 $user = $this->backendAuthSession->getUser();
                 $this->newRelicWrapper->addCustomParameter(Config::ADMIN_USER_ID, $user->getId());
-                $this->newRelicWrapper->addCustomParameter(Config::ADMIN_USER, $user->getUsername());
+                $this->newRelicWrapper->addCustomParameter(Config::ADMIN_USER, $user->getUserName());
                 $this->newRelicWrapper->addCustomParameter(
                     Config::ADMIN_NAME,
-                    $user->getFirstname() . ' ' . $user->getLastname()
+                    $user->getFirstName() . ' ' . $user->getLastName()
                 );
             }
         }
diff --git a/app/code/Magento/NewRelicReporting/Model/Observer/ReportSystemCacheFlushToNewRelic.php b/app/code/Magento/NewRelicReporting/Model/Observer/ReportSystemCacheFlushToNewRelic.php
index 0e3ad1605f948..5500aba195936 100644
--- a/app/code/Magento/NewRelicReporting/Model/Observer/ReportSystemCacheFlushToNewRelic.php
+++ b/app/code/Magento/NewRelicReporting/Model/Observer/ReportSystemCacheFlushToNewRelic.php
@@ -58,8 +58,8 @@ public function execute(Observer $observer)
             if ($user->getId()) {
                 $this->deploymentsFactory->create()->setDeployment(
                     'Cache Flush',
-                    $user->getUsername() . ' flushed the cache.',
-                    $user->getUsername()
+                    $user->getUserName() . ' flushed the cache.',
+                    $user->getUserName()
                 );
             }
         }
diff --git a/app/code/Magento/OfflineShipping/Model/ResourceModel/Carrier/Tablerate.php b/app/code/Magento/OfflineShipping/Model/ResourceModel/Carrier/Tablerate.php
index 500ab253f2a18..961958a54ac1b 100644
--- a/app/code/Magento/OfflineShipping/Model/ResourceModel/Carrier/Tablerate.php
+++ b/app/code/Magento/OfflineShipping/Model/ResourceModel/Carrier/Tablerate.php
@@ -232,10 +232,10 @@ private function importData(array $fields, array $values)
                 $this->_importedRows += count($values);
             }
         } catch (\Magento\Framework\Exception\LocalizedException $e) {
-            $connection->rollback();
+            $connection->rollBack();
             throw new \Magento\Framework\Exception\LocalizedException(__('Unable to import data'), $e);
         } catch (\Exception $e) {
-            $connection->rollback();
+            $connection->rollBack();
             $this->logger->critical($e);
             throw new \Magento\Framework\Exception\LocalizedException(
                 __('Something went wrong while importing table rates.')
diff --git a/app/code/Magento/OfflineShipping/Test/Unit/Block/Adminhtml/Form/Field/ExportTest.php b/app/code/Magento/OfflineShipping/Test/Unit/Block/Adminhtml/Form/Field/ExportTest.php
index cc164e504b665..3e2c7df9087da 100644
--- a/app/code/Magento/OfflineShipping/Test/Unit/Block/Adminhtml/Form/Field/ExportTest.php
+++ b/app/code/Magento/OfflineShipping/Test/Unit/Block/Adminhtml/Form/Field/ExportTest.php
@@ -37,7 +37,7 @@ public function testGetElementHtml()
         $requestMock = $this->createMock(\Magento\Framework\App\RequestInterface::class);
         $requestMock->expects($this->once())->method('getParam')->with('website')->will($this->returnValue(1));
 
-        $mockData = $this->createPartialMock(\StdClass::class, ['toHtml']);
+        $mockData = $this->createPartialMock(\stdClass::class, ['toHtml']);
         $mockData->expects($this->once())->method('toHtml')->will($this->returnValue($expected));
 
         $blockMock->expects($this->once())->method('getRequest')->will($this->returnValue($requestMock));
diff --git a/app/code/Magento/Paypal/Model/ResourceModel/Report/Settlement.php b/app/code/Magento/Paypal/Model/ResourceModel/Report/Settlement.php
index 0796c22db98bf..d4019c6c4a7e0 100644
--- a/app/code/Magento/Paypal/Model/ResourceModel/Report/Settlement.php
+++ b/app/code/Magento/Paypal/Model/ResourceModel/Report/Settlement.php
@@ -90,7 +90,7 @@ protected function _afterSave(\Magento\Framework\Model\AbstractModel $object)
                 }
                 $connection->commit();
             } catch (\Exception $e) {
-                $connection->rollback();
+                $connection->rollBack();
             }
         }
 
diff --git a/app/code/Magento/Paypal/Test/Unit/Model/Payflow/Service/Response/TransactionTest.php b/app/code/Magento/Paypal/Test/Unit/Model/Payflow/Service/Response/TransactionTest.php
index f5c9ab9a3d9f1..93a1072782448 100644
--- a/app/code/Magento/Paypal/Test/Unit/Model/Payflow/Service/Response/TransactionTest.php
+++ b/app/code/Magento/Paypal/Test/Unit/Model/Payflow/Service/Response/TransactionTest.php
@@ -67,7 +67,7 @@ public function gatewayResponseInvariants()
     {
         return [
             "Input data is a string" => ['testInput'],
-            "Input data is an object" => [new \StdClass],
+            "Input data is an object" => [new \stdClass],
             "Input data is an array" => [['test' => 'input']]
         ];
     }
diff --git a/app/code/Magento/Review/Model/ResourceModel/Rating/Option.php b/app/code/Magento/Review/Model/ResourceModel/Rating/Option.php
index 6f68000a1efff..ef4acb6c90cb8 100644
--- a/app/code/Magento/Review/Model/ResourceModel/Rating/Option.php
+++ b/app/code/Magento/Review/Model/ResourceModel/Rating/Option.php
@@ -154,7 +154,7 @@ public function addVote($option)
             }
             $connection->commit();
         } catch (\Exception $e) {
-            $connection->rollback();
+            $connection->rollBack();
             throw new \Exception($e->getMessage());
         }
         return $this;
diff --git a/app/code/Magento/Rule/Model/ResourceModel/AbstractResource.php b/app/code/Magento/Rule/Model/ResourceModel/AbstractResource.php
index 2fdb960521a97..6e685a9a9b978 100644
--- a/app/code/Magento/Rule/Model/ResourceModel/AbstractResource.php
+++ b/app/code/Magento/Rule/Model/ResourceModel/AbstractResource.php
@@ -81,7 +81,7 @@ public function bindRuleToEntity($ruleIds, $entityIds, $entityType)
         try {
             $this->_multiplyBunchInsert($ruleIds, $entityIds, $entityType);
         } catch (\Exception $e) {
-            $this->getConnection()->rollback();
+            $this->getConnection()->rollBack();
             throw $e;
         }
 
diff --git a/app/code/Magento/Sales/Test/Unit/Block/Adminhtml/Items/AbstractItemsTest.php b/app/code/Magento/Sales/Test/Unit/Block/Adminhtml/Items/AbstractItemsTest.php
index 20f7a7061b6b0..a390c43276085 100644
--- a/app/code/Magento/Sales/Test/Unit/Block/Adminhtml/Items/AbstractItemsTest.php
+++ b/app/code/Magento/Sales/Test/Unit/Block/Adminhtml/Items/AbstractItemsTest.php
@@ -84,7 +84,7 @@ public function testGetItemRenderer()
      */
     public function testGetItemRendererThrowsExceptionForNonexistentRenderer()
     {
-        $renderer = $this->createMock(\StdClass::class);
+        $renderer = $this->createMock(\stdClass::class);
         $layout = $this->createPartialMock(
             \Magento\Framework\View\Layout::class,
             ['getChildName', 'getBlock', '__wakeup']
diff --git a/app/code/Magento/Sales/Test/Unit/Block/Adminhtml/Items/AbstractTest.php b/app/code/Magento/Sales/Test/Unit/Block/Adminhtml/Items/AbstractTest.php
index 311e5f697675b..a34373f516c42 100644
--- a/app/code/Magento/Sales/Test/Unit/Block/Adminhtml/Items/AbstractTest.php
+++ b/app/code/Magento/Sales/Test/Unit/Block/Adminhtml/Items/AbstractTest.php
@@ -62,7 +62,7 @@ public function testGetItemRenderer()
      */
     public function testGetItemRendererThrowsExceptionForNonexistentRenderer()
     {
-        $renderer = $this->createMock(\StdClass::class);
+        $renderer = $this->createMock(\stdClass::class);
         $layout = $this->createPartialMock(
             \Magento\Framework\View\Layout::class,
             ['getChildName', 'getBlock', '__wakeup']
diff --git a/app/code/Magento/Sales/Test/Unit/Model/Order/Payment/InfoTest.php b/app/code/Magento/Sales/Test/Unit/Model/Order/Payment/InfoTest.php
index 70e5ad127e44c..293c2eea1231d 100644
--- a/app/code/Magento/Sales/Test/Unit/Model/Order/Payment/InfoTest.php
+++ b/app/code/Magento/Sales/Test/Unit/Model/Order/Payment/InfoTest.php
@@ -179,7 +179,7 @@ public function testDecrypt()
      */
     public function testSetAdditionalInformationException()
     {
-        $this->info->setAdditionalInformation('object', new \StdClass());
+        $this->info->setAdditionalInformation('object', new \stdClass());
     }
 
     /**
diff --git a/app/code/Magento/Sales/Test/Unit/Model/Order/Pdf/AbstractTest.php b/app/code/Magento/Sales/Test/Unit/Model/Order/Pdf/AbstractTest.php
index c91d4edb155a4..0761b5abb5d45 100644
--- a/app/code/Magento/Sales/Test/Unit/Model/Order/Pdf/AbstractTest.php
+++ b/app/code/Magento/Sales/Test/Unit/Model/Order/Pdf/AbstractTest.php
@@ -19,7 +19,7 @@ public function testInsertTotals()
         // Setup parameters, that will be passed to the tested model method
         $page = $this->createMock(\Zend_Pdf_Page::class);
 
-        $order = new \StdClass();
+        $order = new \stdClass();
         $source = $this->createMock(\Magento\Sales\Model\Order\Invoice::class);
         $source->expects($this->any())->method('getOrder')->will($this->returnValue($order));
 
diff --git a/app/code/Magento/Sales/Test/Unit/Model/Order/Pdf/Config/ReaderTest.php b/app/code/Magento/Sales/Test/Unit/Model/Order/Pdf/Config/ReaderTest.php
index b1b51c3f12330..b808a4139e84e 100644
--- a/app/code/Magento/Sales/Test/Unit/Model/Order/Pdf/Config/ReaderTest.php
+++ b/app/code/Magento/Sales/Test/Unit/Model/Order/Pdf/Config/ReaderTest.php
@@ -87,7 +87,7 @@ protected function setUp()
     public function testRead()
     {
         $expectedResult = new \stdClass();
-        $constraint = function (\DOMDOcument $actual) {
+        $constraint = function (\DOMDocument $actual) {
             try {
                 $expected = __DIR__ . '/_files/pdf_merged.xml';
                 \PHPUnit\Framework\Assert::assertXmlStringEqualsXmlFile($expected, $actual->saveXML());
diff --git a/app/code/Magento/Tax/Test/Unit/Model/Calculation/RowBaseAndTotalBaseCalculatorTestCase.php b/app/code/Magento/Tax/Test/Unit/Model/Calculation/RowBaseAndTotalBaseCalculatorTestCase.php
index abb8c49015962..89800e3be872e 100644
--- a/app/code/Magento/Tax/Test/Unit/Model/Calculation/RowBaseAndTotalBaseCalculatorTestCase.php
+++ b/app/code/Magento/Tax/Test/Unit/Model/Calculation/RowBaseAndTotalBaseCalculatorTestCase.php
@@ -9,7 +9,7 @@
 namespace Magento\Tax\Test\Unit\Model\Calculation;
 
 use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
-use Magento\Tax\Model\Calculation\RowbaseCalculator;
+use Magento\Tax\Model\Calculation\RowBaseCalculator;
 use Magento\Tax\Model\Calculation\TotalBaseCalculator;
 
 /**
diff --git a/app/code/Magento/Ui/Config/Converter/HtmlContent.php b/app/code/Magento/Ui/Config/Converter/HtmlContent.php
index f77b4a5285d5a..db874a302bd50 100644
--- a/app/code/Magento/Ui/Config/Converter/HtmlContent.php
+++ b/app/code/Magento/Ui/Config/Converter/HtmlContent.php
@@ -23,7 +23,7 @@ public function convert(\DOMNode $node, array $data)
         if ($node->nodeType == XML_ELEMENT_NODE) {
             $xml = '<?xml version="1.0"?>' . "\n"
                 . '<layout xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">' . "\n"
-                . $node->ownerDocument->saveXml($node) . "\n"
+                . $node->ownerDocument->saveXML($node) . "\n"
                 . '</layout>';
             $items['layout']['xsi:type'] = 'string';
             $items['layout']['name'] = 'layout';
diff --git a/app/code/Magento/User/Model/ResourceModel/User.php b/app/code/Magento/User/Model/ResourceModel/User.php
index 880dec93fc91b..b3e4936266a3f 100644
--- a/app/code/Magento/User/Model/ResourceModel/User.php
+++ b/app/code/Magento/User/Model/ResourceModel/User.php
@@ -222,7 +222,7 @@ protected function _createUserRole($parentId, ModelUser $user)
                     'role_type' => RoleUser::ROLE_TYPE,
                     'user_id' => $user->getId(),
                     'user_type' => UserContextInterface::USER_TYPE_ADMIN,
-                    'role_name' => $user->getFirstname(),
+                    'role_name' => $user->getFirstName(),
                 ]
             );
 
diff --git a/app/code/Magento/User/Model/User.php b/app/code/Magento/User/Model/User.php
index b1b655dddd0a3..2a7d43008f2ad 100644
--- a/app/code/Magento/User/Model/User.php
+++ b/app/code/Magento/User/Model/User.php
@@ -467,7 +467,7 @@ protected function createChangesDescriptionString()
             $changes[] = __('password');
         }
 
-        if ($this->getUsername() != $this->getOrigData('username') && $this->getOrigData('username')) {
+        if ($this->getUserName() != $this->getOrigData('username') && $this->getOrigData('username')) {
             $changes[] = __('username');
         }
 
@@ -515,7 +515,7 @@ protected function sendUserNotificationEmail($changes, $email = null)
      */
     public function getName($separator = ' ')
     {
-        return $this->getFirstname() . $separator . $this->getLastname();
+        return $this->getFirstName() . $separator . $this->getLastName();
     }
 
     /**
@@ -547,7 +547,7 @@ public function authenticate($username, $password)
                 ['username' => $username, 'user' => $this]
             );
             $this->loadByUsername($username);
-            $sensitive = $config ? $username == $this->getUsername() : true;
+            $sensitive = $config ? $username == $this->getUserName() : true;
             if ($sensitive && $this->getId()) {
                 $result = $this->verifyIdentity($password);
             }
diff --git a/app/code/Magento/User/Test/Unit/Model/UserTest.php b/app/code/Magento/User/Test/Unit/Model/UserTest.php
index 3f02cedd32e65..5e0a9a14c2b16 100644
--- a/app/code/Magento/User/Test/Unit/Model/UserTest.php
+++ b/app/code/Magento/User/Test/Unit/Model/UserTest.php
@@ -183,11 +183,11 @@ public function testSendNotificationEmailsIfRequired()
         $this->model->setPassword($password);
         $this->model->setOrigData('password', $origPassword);
 
-        $this->model->setUsername($username);
+        $this->model->setUserName($username);
         $this->model->setOrigData('username', $origUsername);
 
-        $this->model->setFirstname($firstName);
-        $this->model->setLastname($lastName);
+        $this->model->setFirstName($firstName);
+        $this->model->setLastName($lastName);
 
         $this->configMock->expects($this->exactly(4))
             ->method('getValue')
@@ -255,8 +255,8 @@ public function testSendPasswordResetConfirmationEmail()
         $lastName = 'Bar';
 
         $this->model->setEmail($email);
-        $this->model->setFirstname($firstName);
-        $this->model->setLastname($lastName);
+        $this->model->setFirstName($firstName);
+        $this->model->setLastName($lastName);
 
         $this->configMock->expects($this->at(0))
             ->method('getValue')
diff --git a/app/code/Magento/Webapi/Model/Soap/Fault.php b/app/code/Magento/Webapi/Model/Soap/Fault.php
index ee9c194e7c55a..b8ddf4e47d451 100644
--- a/app/code/Magento/Webapi/Model/Soap/Fault.php
+++ b/app/code/Magento/Webapi/Model/Soap/Fault.php
@@ -355,7 +355,7 @@ protected function _getWrappedErrorsXml($wrappedErrors)
 
         $errorsXml = '';
         foreach ($wrappedErrors as $error) {
-            $errorsXml .= $this->_generateErrorNodeXml($error);
+            $errorsXml .= $this->_generateErrorNodeXML($error);
         }
         if (!empty($errorsXml)) {
             $wrappedErrorsNode = self::NODE_DETAIL_WRAPPED_ERRORS;
diff --git a/app/code/Magento/Widget/Test/Unit/Model/Config/FileResolverTest.php b/app/code/Magento/Widget/Test/Unit/Model/Config/FileResolverTest.php
index 65e45b73d88eb..301869a50a713 100644
--- a/app/code/Magento/Widget/Test/Unit/Model/Config/FileResolverTest.php
+++ b/app/code/Magento/Widget/Test/Unit/Model/Config/FileResolverTest.php
@@ -41,7 +41,7 @@ protected function setUp()
 
     public function testGetGlobal()
     {
-        $expected = new \StdClass();
+        $expected = new \stdClass();
         $this->moduleReader
             ->expects($this->once())
             ->method('getConfigurationFiles')
@@ -52,7 +52,7 @@ public function testGetGlobal()
 
     public function testGetDesign()
     {
-        $expected = new \StdClass();
+        $expected = new \stdClass();
         $this->componentDirSearch->expects($this->once())
             ->method('collectFiles')
             ->with(ComponentRegistrar::THEME, 'etc/file')
@@ -63,7 +63,7 @@ public function testGetDesign()
 
     public function testGetDefault()
     {
-        $expected = new \StdClass();
+        $expected = new \stdClass();
         $this->factory->expects($this->once())->method('create')->with([])->willReturn($expected);
         $this->assertSame($expected, $this->object->get('file', 'unknown'));
     }
diff --git a/lib/internal/Magento/Framework/Api/ExtensionAttributesFactory.php b/lib/internal/Magento/Framework/Api/ExtensionAttributesFactory.php
index d7a92460a7f4d..dab0650fc7f6e 100644
--- a/lib/internal/Magento/Framework/Api/ExtensionAttributesFactory.php
+++ b/lib/internal/Magento/Framework/Api/ExtensionAttributesFactory.php
@@ -97,7 +97,7 @@ public function getExtensibleInterfaceName($extensibleClassName)
         }
         $modelReflection = new \ReflectionClass($extensibleClassName);
         if ($modelReflection->isInterface()
-            && $modelReflection->isSubClassOf(self::EXTENSIBLE_INTERFACE_NAME)
+            && $modelReflection->isSubclassOf(self::EXTENSIBLE_INTERFACE_NAME)
             && $modelReflection->hasMethod('getExtensionAttributes')
         ) {
             $this->classInterfaceMap[$extensibleClassName] = $extensibleClassName;
diff --git a/lib/internal/Magento/Framework/App/State/CleanupFiles.php b/lib/internal/Magento/Framework/App/State/CleanupFiles.php
index 4202fd8883ec0..c95caf8310b77 100644
--- a/lib/internal/Magento/Framework/App/State/CleanupFiles.php
+++ b/lib/internal/Magento/Framework/App/State/CleanupFiles.php
@@ -106,7 +106,7 @@ private function emptyDir($code, $subPath = null)
                 $messages[] = $dirPath . $path;
                 try {
                     $dir->delete($path);
-                } catch (FilesystemException $e) {
+                } catch (FileSystemException $e) {
                     $messages[] = $e->getMessage();
                 }
             }
diff --git a/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/ResolverTest.php b/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/ResolverTest.php
index 4348177ef326f..f4560ed31ae49 100644
--- a/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/ResolverTest.php
+++ b/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/ResolverTest.php
@@ -47,7 +47,7 @@ public function testGetTagsForNotObject()
     public function testGetTagsForObject()
     {
         $strategyReturnValue = ['test tag'];
-        $object = new \StdClass;
+        $object = new \stdClass;
         $this->strategy->expects($this->once())
             ->method('getTags')
             ->with($object)
diff --git a/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/DummyTest.php b/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/DummyTest.php
index e8c76048f4eac..ad04326064587 100644
--- a/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/DummyTest.php
+++ b/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/DummyTest.php
@@ -28,7 +28,7 @@ public function testGetTagsWithObject()
     {
         $emptyArray = [];
 
-        $this->assertEquals($emptyArray, $this->model->getTags(new \StdClass));
+        $this->assertEquals($emptyArray, $this->model->getTags(new \stdClass));
 
         $identityInterface = $this->getMockForAbstractClass(\Magento\Framework\DataObject\IdentityInterface::class);
         $this->assertEquals($emptyArray, $this->model->getTags($identityInterface));
diff --git a/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/FactoryTest.php b/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/FactoryTest.php
index 7f570d9f13523..8964bd70f0ba8 100644
--- a/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/FactoryTest.php
+++ b/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/FactoryTest.php
@@ -55,7 +55,7 @@ public function testGetStrategyWithScalar()
 
     public function testGetStrategyWithObject()
     {
-        $this->assertEquals($this->dummyStrategy, $this->model->getStrategy(new \StdClass));
+        $this->assertEquals($this->dummyStrategy, $this->model->getStrategy(new \stdClass));
     }
 
     public function testGetStrategyWithIdentityInterface()
diff --git a/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/IdentifierTest.php b/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/IdentifierTest.php
index e2039c0517c53..d0fcf9d8a739d 100644
--- a/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/IdentifierTest.php
+++ b/lib/internal/Magento/Framework/App/Test/Unit/Cache/Tag/Strategy/IdentifierTest.php
@@ -28,7 +28,7 @@ public function testGetWithScalar()
 
     public function testGetTagsWithObject()
     {
-        $this->assertEquals([], $this->model->getTags(new \StdClass));
+        $this->assertEquals([], $this->model->getTags(new \stdClass));
     }
 
     public function testGetTagsWithIdentityInterface()
diff --git a/lib/internal/Magento/Framework/App/Test/Unit/Request/HttpTest.php b/lib/internal/Magento/Framework/App/Test/Unit/Request/HttpTest.php
index 450e1ed0b3a00..66eee671e17d3 100644
--- a/lib/internal/Magento/Framework/App/Test/Unit/Request/HttpTest.php
+++ b/lib/internal/Magento/Framework/App/Test/Unit/Request/HttpTest.php
@@ -363,7 +363,7 @@ public function testIsSafeMethodTrue($httpMethod)
     {
         $this->_model = $this->getModel();
         $_SERVER['REQUEST_METHOD'] = $httpMethod;
-        $this->assertEquals(true, $this->_model->IsSafeMethod());
+        $this->assertEquals(true, $this->_model->isSafeMethod());
     }
 
     /**
@@ -375,7 +375,7 @@ public function testIsSafeMethodFalse($httpMethod)
     {
         $this->_model = $this->getModel();
         $_SERVER['REQUEST_METHOD'] = $httpMethod;
-        $this->assertEquals(false, $this->_model->IsSafeMethod());
+        $this->assertEquals(false, $this->_model->isSafeMethod());
     }
 
     public function httpSafeMethodProvider()
diff --git a/lib/internal/Magento/Framework/Code/Test/Unit/Reader/_files/ClassesForArgumentsReader.php b/lib/internal/Magento/Framework/Code/Test/Unit/Reader/_files/ClassesForArgumentsReader.php
index 4508bccf54cdc..7fc2b13442bc2 100644
--- a/lib/internal/Magento/Framework/Code/Test/Unit/Reader/_files/ClassesForArgumentsReader.php
+++ b/lib/internal/Magento/Framework/Code/Test/Unit/Reader/_files/ClassesForArgumentsReader.php
@@ -132,7 +132,7 @@ public function __construct(
         $this->_arrayVariable = $arrayVariable;
     }
 }
-class ThirdClassForParentCall extends firstClassForParentCall
+class ThirdClassForParentCall extends FirstClassForParentCall
 {
     /**
      * @var stdClass
@@ -155,7 +155,7 @@ public function __construct(\stdClass $stdClassObject, \ClassExtendsDefaultPhpTy
         $this->_secondClass = $secondClass;
     }
 }
-class WrongArgumentsOrder extends firstClassForParentCall
+class WrongArgumentsOrder extends FirstClassForParentCall
 {
     /**
      * @var stdClass
@@ -178,7 +178,7 @@ public function __construct(\stdClass $stdClassObject, \ClassExtendsDefaultPhpTy
         $this->_secondClass = $secondClass;
     }
 }
-class ArgumentsOnSeparateLines extends firstClassForParentCall
+class ArgumentsOnSeparateLines extends FirstClassForParentCall
 {
     /**
      * @var stdClass
diff --git a/lib/internal/Magento/Framework/Data/Test/Unit/Tree/Node/CollectionTest.php b/lib/internal/Magento/Framework/Data/Test/Unit/Tree/Node/CollectionTest.php
index 58e6378759010..e91ec72dae112 100644
--- a/lib/internal/Magento/Framework/Data/Test/Unit/Tree/Node/CollectionTest.php
+++ b/lib/internal/Magento/Framework/Data/Test/Unit/Tree/Node/CollectionTest.php
@@ -40,7 +40,7 @@ public function testOffsets()
         $this->assertSame($this->collection->offsetExists('node1'), true);
         $this->collection->offsetSet('node1', 'Hello');
         $this->assertSame($this->collection->offsetExists('node1'), true);
-        $this->assertSame($this->collection->offsetget('node1'), 'Hello');
+        $this->assertSame($this->collection->offsetGet('node1'), 'Hello');
         $this->collection->offsetUnset('node1');
         $this->assertSame($this->collection->offsetExists('node1'), false);
     }
diff --git a/lib/internal/Magento/Framework/Xml/Security.php b/lib/internal/Magento/Framework/Xml/Security.php
index 72af506a3294e..e502429e4511a 100644
--- a/lib/internal/Magento/Framework/Xml/Security.php
+++ b/lib/internal/Magento/Framework/Xml/Security.php
@@ -72,7 +72,7 @@ function ($errno, $errstr) {
             E_WARNING
         );
 
-        $result = (bool)$document->loadXml($xmlContent, LIBXML_NONET);
+        $result = (bool)$document->loadXML($xmlContent, LIBXML_NONET);
         restore_error_handler();
         // Entity load to previous setting
         libxml_disable_entity_loader($loadEntities);