Keeping syntax compatibility of build.xml while updating to junit 5

Question

I maintain a library that our larger org uses for its ant configuration files. I am trying to update from a junit 4 backend to junit 5 backend with minimal disruption to end users.

The main issue I am running into is output formatters. We have a macrodef that accepts a <element name="test-formatter"/> that is used like

<runmultipletest foo=...>
    <test-formatter>
        <formatter type="plain" usefile="false" />
        <formatter type="xml" usefile="true" />
    </test-formatter>
    <runmultipletest-fileset>
       <fileset refid="${junit.integration.fileset}"/>
   </runmultipletest-fileset>
</runmultipletest>

inside the macrodef this was fed into

<batchtest todir="@{test.todir}" skipNonTests="@{skipNonTests}">
    <test-formatter/>
    <runmultipletest-fileset/>
</batchtest>

Now I am upgrading to junit 5. Is it possible without breaking backward compatibility with the existing format end users use to transform the

<formatter type="plain" usefile="false" />
<formatter type="xml" usefile="true" />

into

<listener type="legacy-plain" sendSysOut="true" sendSysErr="true"/>
<listener type="legacy-xml" sendSysErr="true" sendSysOut="true" outputDir="@{test.todir}"/>

from inside my macrodef? I can figure out the XSLT to transform the xml in to what I want but I don't know Ant well enough to know if it is possible to transform the passed in element and then have junitlauncher use it.

Answer 1

Well, it's unclear to me how you switch from JUnit 4 to JUnit 5, anyway you could be able to pass a parameter to the macrodef in order to change the content of test-formatter, like the following:

<macrodef name="test-formatter">
  <attribute name="version" />
  <sequential>
    <if>
      <equals arg1="@{version}" arg2="5" />
      <then>
         <listener type="legacy-plain" sendSysOut="true" sendSysErr="true"/>
         <listener type="legacy-xml" sendSysErr="true" sendSysOut="true" outputDir="@{test.todir}"/>
      </then>
      <else>
         <formatter type="plain" usefile="false" />
         <formatter type="xml" usefile="true" />
      </else>
    </if>
  </sequential>
</macrodef>

So when you execute the tests you can choose which test-formatter use:

<batchtest todir="@{test.todir}" skipNonTests="@{skipNonTests}">
    <test-formatter />
    <runmultipletest-fileset />
</batchtest>

rather than:

<batchtest todir="@{test.todir}" skipNonTests="@{skipNonTests}">
    <test-formatter version="5" />
    <runmultipletest-fileset />
</batchtest>

If I'm right and you already have an attribute that holds the JUnit version you can pass it as parameter to the test-formatter as discuss above.

I hope it helps you, bye.