magento-test/app/code/Magento/Customer/Test/Mftf/ActionGroup/AssertStorefrontDefaultWelcomeMessageActionGroup.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
-->

<actionGroups xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:noNamespaceSchemaLocation="urn:magento:mftf:Test/etc/actionGroupSchema.xsd">
    <actionGroup name="AssertStorefrontDefaultWelcomeMessageActionGroup">
        <annotations>
            <description>Validates that the Welcome message is present and correct and not you link absent.</description>
        </annotations>

        <waitForElementVisible selector="{{StorefrontPanelHeaderSection.welcomeMessage}}" stepKey="waitDefaultMessage"/>
        <waitForText userInput="Default welcome msg!" selector="{{StorefrontPanelHeaderSection.welcomeMessage}}" stepKey="verifyDefaultMessage"/>
        <dontSeeElement selector="{{StorefrontPanelHeaderSection.notYouLink}}" stepKey="checkAbsenceLinkNotYou"/>
    </actionGroup>
</actionGroups>