build.xml

<project name="SpockExample"
         default="test"
         xmlns:groovy="antlib:org.codehaus.groovy.ant"
         xmlns:ivy="antlib:org.apache.ivy.ant">
    <!-- Various Paths -->
    <property name="test.src.dir"
              location="src/test/groovy"/>
    <property name="test.resource.dir"
              location="src/test/resources"/>
    <property name="build.dir"
              location="ant/build"/>
    <property name="lib.dir"
              location="ant/lib"/>
    <property name="classes.dir"
              location="${build.dir}/classes"/>

    <!-- Ivy Properties -->
    <property name="config.ivy.version"
              value="2.5.3"/>
    <property name="ivy.jar.dir"
              location="${lib.dir}/ivy"/>
    <property name="ivy.jar.filename"
              value="ivy-${config.ivy.version}.jar"/>
    <property name="ivy.jar.file"
              location="${ivy.jar.dir}/${ivy.jar.filename}"/>

    <target name="init">
        <echo message="Buildfile for ${ant.project.name} (${ant.file})"
              level="info"/>
        <fail message="Ant 1.10.6 or newer is needed for ${ant.project.name} to build, please install it and rerun (found Ant version: '${ant.version}')">
            <condition>
                <not>
                    <antversion atleast="1.10.6"/>
                </not>
            </condition>
        </fail>
        <fail message="Java 8 or newer is needed for ${ant.project.name} to build, please install it and rerun (found Java version: '${ant.java.version}')">
            <condition>
                <not>
                    <javaversion atleast="1.8"/>
                </not>
            </condition>
        </fail>
        <fail message="The ant-optional package is needed for ${ant.project.name} to build, please install it and rerun">
            <condition>
                <not>
                    <and>
                        <available classname="org.apache.tools.ant.taskdefs.optional.depend.Depend"/>
                        <available classname="org.apache.tools.ant.taskdefs.optional.TraXLiaison"/>
                    </and>
                </not>
            </condition>
        </fail>
    </target>

    <target name="check-ivy"
            depends="init">
        <available property="ivy.jar.present"
                   file="${ivy.jar.file}"
                   type="file"/>
    </target>

    <target name="download-ivy"
            depends="init,check-ivy"
            unless="ivy.jar.present">
        <mkdir dir="${ivy.jar.dir}"/>
        <get src="https://repo.maven.apache.org/maven2/org/apache/ivy/ivy/${config.ivy.version}/ivy-${config.ivy.version}.jar"
             dest="${ivy.jar.file}"
             usetimestamp="true"/>
    </target>

    <target name="init-ivy"
            depends="init,download-ivy">
        <property name="ivy.retrieve.pattern"
                  value="${lib.dir}/[conf]/[artifact](-[classifier]).[ext]"/>
        <taskdef resource="org/apache/ivy/ant/antlib.xml"
                 classpath="${ivy.jar.file}"
                 loaderref="ivy.loader"
                 uri="antlib:org.apache.ivy.ant"/>
    </target>

    <target name="retrieve"
            description="retrieve the dependencies"
            depends="init,init-ivy">
        <ivy:retrieve sync="true"/>
        <ivy:retrieve pattern="${lib.dir}/ivy/[artifact]-[revision].[ext]"
                      organisation="org.apache.ivy"
                      module="ivy"
                      revision="${config.ivy.version}"
                      conf="default"
                      inline="true"/>
    </target>

    <target name="clean"
            depends="init"
            description="clean up intermediate files">
        <delete includeemptydirs="true"
                failonerror="false">
            <fileset dir="${classes.dir}"
                     defaultexcludes="false"/>
        </delete>
    </target>

    <target name="clean-all"
            depends="init"
            description="clean up lib.dir, classes.dir, and build.dir completely">
        <delete includeemptydirs="true"
                failonerror="false">
            <fileset dir="${lib.dir}"
                     defaultexcludes="false"/>
            <fileset dir="${classes.dir}"
                     defaultexcludes="false"/>
            <fileset dir="${build.dir}"
                     defaultexcludes="false"/>
        </delete>
    </target>

    <target name="compile-test"
            depends="init,retrieve">
        <mkdir dir="${classes.dir}/test"/>
        <depend srcDir="${test.src.dir}"
                destDir="${classes.dir}/test"
                cache="${classes.dir}"/>
        <dependset>
            <srcfilelist files="build.xml"/>
            <srcfilelist files="ivy.xml"/>
            <srcfilelist files="ivysettings.xml"/>
            <targetfileset dir="${classes.dir}/test"/>
        </dependset>
        <taskdef resource="org/codehaus/groovy/antlib.xml"
                 uri="antlib:org.codehaus.groovy.ant">
            <classpath>
                <fileset dir="${lib.dir}/groovy-ant"
                         includes="*.jar"/>
            </classpath>
        </taskdef>
        <groovy:groovyc srcdir="${test.src.dir}"
                        destdir="${classes.dir}/test"
                        encoding="UTF-8"
                        includeAntRuntime="false"
                        fork="true">
            <groovy:classpath id="classpath.test">
                <fileset dir="${lib.dir}/test"
                         includes="*.jar"/>
            </groovy:classpath>
        </groovy:groovyc>
    </target>

    <target name="test"
            depends="init,retrieve,compile-test"
            description="run unit tests">
        <delete dir="${build.dir}/test/raw-reports"/>
        <mkdir dir="${build.dir}/test/raw-reports"/>
        <junitlauncher printsummary="true"
                       failureproperty="tests.failed">
            <classpath refid="classpath.test"/>
            <classpath location="§{test.resource.dir}"/>
            <classpath location="${classes.dir}/test"/>
            <classpath location="${ant.library.dir}/ant.jar"/>
            <classpath location="${ant.library.dir}/ant-junitlauncher.jar"/>
            <listener type="legacy-xml"
                      outputDir="${build.dir}/test/raw-reports"/>
            <testclasses>
                <fork includeJUnitPlatformLibraries="false"
                      includeAntRuntimeLibraries="false"/>
                <fileset dir="${classes.dir}/test">
                    <scriptselector language="groovy">
                        <classpath>
                            <fileset dir="${lib.dir}/groovy-script"
                                     includes="*.jar"/>
                        </classpath>
                        <![CDATA[
                            import org.spockframework.buildsupport.SpecClassFileFinder
                            self.selected = new SpecClassFileFinder().isRunnableSpec(file)
                        ]]>
                    </scriptselector>
                </fileset>
            </testclasses>
        </junitlauncher>
        <mkdir dir="${build.dir}/test/merged-reports"/>
        <junitreport todir="${build.dir}/test/merged-reports">
            <fileset dir="${build.dir}/test/raw-reports"/>
            <report todir="${build.dir}/test/reports"/>
        </junitreport>
        <fail message="Unit test(s) failed! See reports at ${build.dir}/test/reports/index.html"
              if="tests.failed"/>
    </target>
</project>