youys
/
ant

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<document>

  <properties>
    <index value="1"/>
    <title>AntUnit</title>
  </properties>

  <body>

    <section name="Idea">
      <p>Initially all tests for Ant tasks were written as individual
      <a href="http://www.junit.org/">JUnit</a> test cases.  Pretty
      soon it was clear that most tests needed to perform common tasks
      like reading a build file, initializing a project instance with
      it and executing a target.  At this point <a
      href="http://svn.apache.org/viewcvs.cgi/ant/core/trunk/src/testcases/org/apache/tools/ant/BuildFileTest.java">BuildFileTest</a>
      was invented, a base class for almost all task test cases.</p>

      <p>BuildFileTest works fine and in fact has been picked up by <a
      href="http://ant-contrib.sf.net/">the Ant-Contrib Project</a>
      and others as well.</p>

      <p>Over time a new pattern evolved, more and more tests only
      executed a target and didn't check any effects.  Instead that
      target contained the assertions as a <code>&lt;fail&gt;</code>
      task.  This is an example taken from the build file for the
      ANTLR task (using Ant 1.7 features):</p>

      <source><![CDATA[
  <target name="test3" depends="setup">
    <antlr target="antlr.g" outputdirectory="${tmp.dir}"/>
    <fail>
      <condition>
        <!-- to prove each of these files exists;
             ANTLR >= 2.7.6 leaves behind new (.smap) files as well. -->
        <resourcecount when="ne" count="5">
          <fileset dir="${tmp.dir}">
            <include name="CalcParserTokenTypes.txt" />
            <include name="CalcParserTokenTypes.java" />
            <include name="CalcLexer.java" />
            <include name="CalcParser.java" />
            <include name="CalcTreeWalker.java" />
          </fileset>
        </resourcecount>
      </condition>
    </fail>
  </target>
]]></source>

      <p>where the corresponding JUnit testcase has been reduced
      to</p>

      <source><![CDATA[
...
public class ANTLRTest extends BuildFileTest {

    private final static String TASKDEFS_DIR = "src/etc/testcases/taskdefs/optional/antlr/";

    public ANTLRTest(String name) {
        super(name);
    }

    public void setUp() {
        configureProject(TASKDEFS_DIR + "antlr.xml");
    }

    public void tearDown() {
        executeTarget("cleanup");
    }

    public void test3() {
        executeTarget("test3");
    }
...
}
]]></source>

      <p>This approach has a couple of advantages, one of them is that
      it is very easy to translate an example build file from a bug
      report into a test case.  If you ask a user for a testcase for a
      given bug in Ant, he now doesn't need to understand JUnit or how
      to fit a test into Ant's existing tests any more.</p>

      <p>AntUnit takes this approach to testing even further, it
      removes JUnit completely and it comes with a set of predefined
      <code>&lt;assert&gt;</code> tasks in order to reuse common kind
      of checks.</p>

      <p>It turns out that AntUnit lends itself as a solution to other
      problems as well.  The assertions are an easy way to validate a
      setup before even starting the build process, for example.
      AntUnit could also be used for functional and integration tests
      outside of the scope of Ant tasks (assert contents of databases
      after running an application, assert contents of HTTP responses
      ...).  This is an area that will need more research.</p>
    </section>

    <section name="Concepts">
      <subsection name="antunit Task">
        <p>The &lt;antunit&gt; task drives the tests much like
        &lt;junit&gt; does for JUnit tests.</p>

        <p>When called on a build file, the task will start a new Ant
        project for that build file and scan for targets with names
        that start with "test".  For each such target it then will</p>
        <ol>
          <li>Execute the target named setUp, if there is one.</li>
          <li>Execute the target itself - if this target depends on
          other targets the normal Ant rules apply and the dependent
          targets are executed first.</li>
          <li>Execute the target names tearDown, if there is one.</li>
        </ol>

      </subsection>
      <subsection name="Assertions">

        <p>The base task is <code>&lt;assertTrue&gt;</code>.  It
        accepts a single nested condition and throws a subclass of
        BuildException named AssertionFailedException if that
        condition evaluates to false.</p>

        <p>This task could have been implemented using
        <code>&lt;macrodef&gt;</code> and <code>&lt;fail&gt;</code>,
        but in fact it is a "real" task so that it is possible to
        throw a subclass of BuildException.  The
        <code>&lt;antunit&gt;</code> task catches this exception and
        marks the target as failed, any other type of Exception
        (including other BuildException) are test errors.</p>

        <p>Together with <code>&lt;assertTrue&gt;</code> there are
        many predefined assertions for common conditions, most of
        these are only macros.</p>

      </subsection>

      <subsection name="Other Tasks">

        <p>The <code>&lt;logcapturer&gt;</code> captures all messages
        that pass Ant's logging system and provides them via a
        reference inside of the project.  If you want to assert
        certain log messages, you need to start this task (prior to
        your target under test) and use the
        <code>&lt;assertLogContains&gt;</code> assertion.</p>

        <p><code>&lt;expectFailure&gt;</code> is a task container that
        catches any BuildException thrown by tasks nested into it.  If
        no exception has been thrown it will cause a test failure (by
        throwing an AssertionFailedException).</p>
      </subsection>

      <subsection name="AntUnitListener">
        <p>Part of the library is the <code>AntUnitListener</code>
        interface that can be used to record test results.  The
        &lt;antunit&gt; task accepts arbitrary many listeners and
        relays test results to them.</p>

        <p>Currently two implementations -
        <code>&lt;plainlistener&gt;</code> and <code>xmllistener</code> 
        modelled after the "plain" and "xml"
        JUnit listeners - are bundled with the library.</p>
      </subsection>
    </section>

    <section name="Examples">

      <p>This is a way to test that <code>&lt;touch&gt;</code>
      actually creates a file if it doesn't exist:</p>

      <source><![CDATA[
<project xmlns:au="antlib:org.apache.ant.antunit">
  <!-- is called prior to the test -->
  <target name="setUp">
    <property name="foo" value="foo"/>
  </target>

  <!-- is called after the test, even if that caused an error -->
  <target name="tearDown">
    <delete file="${foo}" quiet="true"/>
  </target>

  <!-- the actual test case -->
  <target name="testTouchCreatesFile">
    <au:assertFileDoesntExist file="${foo}"/>
    <touch file="${foo}"/>
    <au:assertFileExists file="${foo}"/>
  </target>
</project>
]]></source>

      <p>When running a task like</p>

      <source><![CDATA[
    <au:antunit>
      <fileset dir="." includes="touch.xml"/>
      <au:plainlistener/>
    </au:antunit>
]]></source>

      <p>from a buildfile of its own you'll get a result that looks like</p>

      <source><![CDATA[
[au:antunit] Build File: /tmp/touch.xml
[au:antunit] Tests run: 1, Failures: 0, Errors: 0, Time elapsed: 0.249 sec
[au:antunit] Target: testTouchCreatesFile took 0.183 sec

BUILD SUCCESSFUL
Total time: 1 second
]]></source>

    </section>
  </body>
</document>