How to test Hello World

Summary

How to test a simple groovy program that produces output.

HelloWorld.groovy
println 'Hello World'
HelloWorldTest.gant
@GrabResolver(name='atlassian', root='https://maven.atlassian.com/content/groups/public/')
@Grab(group='org.swift.tools', module='gint', version='1.4.0')
import org.swift.tools.*
includeTool << Gint

gint.initialize(this) // required
gint.setCmdGenerator('groovy', [file: 'helloWorld.groovy']) // set default cmd generator to call the script

gint.add(name: 'hello', data: 'Hello World') // confirm that Hello World is produced by the script

gint.finalizeTest() // final preparations for running tests
Output
gant -f helloWorldTest.gant 

= = = = = =   helloWorldTest started at Fri Feb 25 21:13:08 CST 2011   = = = = = =

    [start] hello
   [ending] hello
 [complete] hello - 1.179 secs


     [info] Successful testcases  . . . . . . . . . . : 1    <<< TEST SUCCESSFUL
     [info] Total testcases . . . . . . . . . . . . . : 1
     [info] Elapsed run time  . . . . . . . . . . . . : 3.054 secs 

= = = = = =   helloWorldTest completed at Fri Feb 25 21:13:09 CST 2011 = = = = = =

BUILD SUCCESSFUL
Total time: 5.53 seconds