MC-23058: Template strict mode is not set for unsaved template previews

Author: nathanjosiah

app/code/Magento/Newsletter/Test/Mftf/ActionGroup/AdminNewsletterTemplateActionGroup.xml

@@ -34,7 +34,7 @@
         <waitForElementVisible selector="{{BasicFieldNewsletterSection.templateName}}" stepKey="waitForPreviewButton"/>
         <click selector="{{BasicFieldNewsletterSection.preview}}" stepKey="clickPreview"/>
         <switchToNextTab stepKey="switchToPreviewTab"/>
-        <waitForPageLoad stepKey="waitForPreviewTabLoaded"/>
+        <waitForElementVisible selector="{{BasicFieldNewsletterSection.previewIframe}}" stepKey="waitForIframeVisible"/>
         <executeJS function="document.getElementById('preview_iframe').sandbox.add('allow-scripts')" stepKey="addSandboxValue"/>
         <switchToIFrame userInput="preview_iframe" stepKey="switchToIframe"/>
         <waitForPageLoad stepKey="waitForPreviewIframeLoaded"/>
@@ -44,7 +44,7 @@
         <arguments>
             <argument name="Newsletter" defaultValue="BasicFieldNewsletterSection"/>
         </arguments>
-        <see userInput="{{Newsletter.expectedTemplate}}" stepKey="checkTemplateContainsText"/>
+        <waitForText userInput="{{Newsletter.expectedTemplate}}" stepKey="checkTemplateContainsText"/>
     </actionGroup>
 
 </actionGroups>

app/code/Magento/Newsletter/Test/Mftf/Section/NewsletterTemplateSection.xml

@@ -17,6 +17,7 @@
         <element name="searchButton" type="button" selector=".admin__filter-actions button[title=Search]"/>
         <element name="searchInput" type="input" selector="input[name=code]"/>
         <element name="preview" type="button" selector="button[data-role='template-preview']"/>
+        <element name="previewIframe" type="iframe" selector="#preview_iframe"/>
     </section>
     <section name="NewsletterWYSIWYGSection">
         <element name="TextArea" type="text" selector="#text" />