Ant – Execute Grunt and fail it on error

I want to execute a Grunt build in an Ant build project. This could be done by using <exec>.

<?xml version="1.0" encoding="UTF-8"?>
<project name="Ant Called Grunt" default="grunt" basedir=".">
  <target name="grunt">
    <exec executable="grunt" dir="${basedir}">
      <arg value="build"/>
    </exec>
  </target>
</project>

It works quite well, but then i realize if there is error in the grunt execution, Ant will still mark the Ant build successful and this may lead to some downstream failure in a continuous integration workflow.

To avoid that, i add a checking on the Grunt output.

<?xml version="1.0" encoding="UTF-8"?>
<project name="Ant Called Grunt" default="grunt" basedir=".">
  <target name="grunt">
    <exec executable="grunt" dir="${basedir}" outputproperty="log">
      <arg value="kit"/>
    </exec>

    <echo message="${log}"/>
    <condition property="onSuccess">
      <matches pattern="Done, without errors." string="${log}"/>
    </condition>
    <fail message="Grunt failed!" unless="onSuccess"/>
  </target>
</project>

The idea is to collect the Grunt output in outputproperty and check if the string Done, without errors. exists.

Done =)

Reference:

• StackOverflow – Ant: how to fail if property contains a certain string
• Ant – Exec