galaxy/test/functional/tools/metadata_column_names.xml

<tool id="metadata_columns" name="metadata_columns" version="1.0.0">
    <description>Tests whether metadata is being set correctly.</description>
    <command><![CDATA[
        cp '$input' '$output'
    ]]></command>
    <inputs>
        <param name="input" type="data" multiple="false" />
    </inputs>
    <outputs>
        <data format="tabular" name="output">
            <actions>
                <action name="column_names" type="metadata" default="First,${input.name}" />
            </actions>
        </data>
    </outputs>
    <tests>
        <test>
            <param name="input" value="2.tabular" />
            <output name="output">
                <metadata name="column_names" value="First,2.tabular"/>
            </output>
        </test>
    </tests>
</tool>