magento-test/app/code/Magento/Checkout/Test/Mftf/ActionGroup/StorefrontAddToTheCartActionGroup.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="StorefrontAddToTheCartActionGroup">
        <annotations>
            <description>Scrolls to the Add To Cart button. Clicks on Add To Cart.</description>
        </annotations>

        <waitForPageLoad stepKey="waitForPageLoad"/>
        <scrollTo selector="{{StorefrontProductActionSection.addToCart}}"  stepKey="scrollToAddToCartButton"/>
        <waitForElementNotVisible selector="{{StorefrontProductActionSection.addToCartDisabled}}" stepKey="waitForAddToCartButtonToRemoveDisabledState"/>
        <waitForElementClickable selector="{{StorefrontProductActionSection.addToCart}}" stepKey="waitForAddToCartButton"/>
        <click selector="{{StorefrontProductActionSection.addToCart}}" stepKey="addToCart"/>
        <waitForPageLoad stepKey="waitForPageToLoad"/>
        <waitForElementVisible selector="{{StorefrontMessagesSection.success}}" stepKey="waitForSuccessMessage"/>
    </actionGroup>
</actionGroups>