galaxy/test/functional/tools/float_default.xml

<tool id="float_default" name="Test float default" version="0.1.0">
    <command><![CDATA[
echo ${float($input1) + float($input2) + float($input3)} > '$out_file1'
    ]]></command>
    <inputs>
        <param name="input1" type="float" value="0.0" label="Float with default 0.0" />
        <param name="input2" type="float" value="" label="Float with default empty string" />
        <!-- Not needed any more to have `value=""` when there is no good default -->
        <param name="input3" type="float" label="Float with no default value" />
    </inputs>
    <outputs>
        <data name="out_file1" format="txt"/>
    </outputs>
    <tests>
        <test>
            <param name="input1" value="1.0" />
            <param name="input2" value="2.0" />
            <param name="input3" value="3.0" />
            <output name="out_file1">
                <assert_contents>
                    <has_line line="6.0" />
                </assert_contents>
            </output>
        </test>
        <!-- Test that it fails if a non-optional float param is not set -->
        <test expect_failure="true">
            <param name="input1" value="1.0" />
            <param name="input2" value="2.0" />
        </test>
    </tests>
    <help>
    </help>
</tool>