ant/src/etc/testcases/taskdefs/taskdef.xml

<?xml version="1.0"?>

<project name="xxx-test" basedir="." default="test1">

  <path id="testclasses">
    <pathelement location="../../../../build/testcases" />
    <pathelement path="${java.class.path}" />
  </path>

  <taskdef name="global"
           classname="org.example.tasks.TaskdefTestContainerTask">
    <classpath refid="testclasses" />
  </taskdef>

  <target name="test1">
    <taskdef/>
  </target>

  <target name="test2">
    <taskdef name=""/>
  </target>

  <target name="test3">
    <taskdef classname=""/>
  </target>

  <target name="test4">
    <taskdef name="" classname="oops"/>
  </target>

  <target name="test5">
    <taskdef name="test" classname="org.apache.tools.ant.Project" />
  </target>

  <target name="test5a">
    <taskdef name="test" classname="org.apache.tools.ant.taskdefs.Copy" />
  </target>

  <target name="test6">
    <taskdef name="test6"
             classname="org.example.tasks.TaskdefTestSimpleTask">
      <classpath refid="testclasses" />
    </taskdef>
    <test6>
      <echo message="worked" />
    </test6>
  </target>

  <target name="test7">
    <taskdef name="test7"
             classname="org.example.tasks.TaskdefTestContainerTask">
      <classpath refid="testclasses" />
    </taskdef>
    <test7>
      <echo message="worked" />
    </test7>
  </target>

  <target name="testGlobal">
    <global>
      <echo message="worked" />
    </global>
  </target>

  <target name="testOverride">
    <taskdef name="copy" classname="org.apache.tools.ant.taskdefs.Echo" />
    <copy>In target</copy>
    <sequential>
      <copy>In TaskContainer</copy>
    </sequential>
  </target>

</project>