This is a piece of my Jenkinsfile:

emailext([
        attachmentsPattern: '**/build/*.log',
        subject: 'Hello World',
        recipientProviders: [developers(), requestor()],
        to: '$DEFAULT_RECIPIENTS',
        body: '''
            <p>Test summary:</p>
            <ul>
                <li><a href="${BUILD_URL}">Status: ${BUILD_STATUS}</a></li>
                <li><a href="${BUILD_URL}/flowGraphTable">Executed steps</a></li>
                <li><a href="${BUILD_URL}/parsed_console">Errors and warnings</a></li>
                <li>Test results:</li>
                ${testResults}
            </ul>
        ''',
        mimeType: 'text/html'
])

But unfortunately testResults variable doesn’t get interpolated:

How can I fix?

Also, I have tried to replace ''' with """, like this:

emailext([
        attachmentsPattern: '**/build/*.log',
        subject: 'Hello World',
        recipientProviders: [developers(), requestor()],
        to: '$DEFAULT_RECIPIENTS',
        body: """
            <p>Test summary:</p>
            <ul>
                <li><a href="${BUILD_URL}">Status: ${BUILD_STATUS}</a></li>
                <li><a href="${BUILD_URL}/flowGraphTable">Executed steps</a></li>
                <li><a href="${BUILD_URL}/parsed_console">Errors and warnings</a></li>
                <li>Test results:</li>
                ${testResults}
            </ul>
        """,
        mimeType: 'text/html'
])

But I got this error in my Jenkins console output:

Error when executing always post condition:
Also:   org.jenkinsci.plugins.workflow.actions.ErrorAction$ErrorId: 4fb4675f-4b24-4e5a-8344-835e9d514202
groovy.lang.MissingPropertyException: No such property: BUILD_STATUS for class: groovy.lang.Binding