Handy Gradle Recipes

Nov 8, 2017

I’ve been trying to simplify my tools lately – less reliance on Intelij IDEA and using the command line more and more. At times, I feel like my workflow has sped up because of a faster feedback loop. But in the midst of that, I’ve found some things that I wanted to do and had to look on how to do that. Luckily, I’m using Gradle as the build tool in my projects so a lot of those things are fairly straight-forward once you figure out how. Therefore, I’ve gathered some nice recipes for Gradle usage.

Run a single test

This one wasn’t as intuitive as I thought it was – you just need to set a system property

gradle -Dtest.single=TestClassName test

Print out the output of all unit tests

By default, the output of the tests results are in build/reports/tests. Yeah you get what tests failed in the terminal window but you have to look at the test reports to see what the log messages said, etc. So you can add the following to your build.gradle:

test {
    testLogging {
        showStandardStreams = true
    }
}

I wouldn’t do this for projects with 1,000+ unit tests, but it’s handy for the running a single unit test and seeing all the output in one screen.

Show each unit test, pass or fail.

This isn’t one I use very much, but it’s handy for demos, in particular TDD presentations.

// import these
import org.gradle.api.tasks.testing.logging.TestExceptionFormat
import org.gradle.api.tasks.testing.logging.TestLogEvent

// than add this
tasks.withType(Test) {
    testLogging {
        events TestLogEvent.FAILED,
               TestLogEvent.PASSED,
               TestLogEvent.SKIPPED,
               TestLogEvent.STANDARD_ERROR,
               TestLogEvent.STANDARD_OUT
        exceptionFormat TestExceptionFormat.FULL
        showCauses true
        showExceptions true
        showStackTraces true
    }
}

Give out JVM and Gradle Info

This one came from a strange situation on our CI server. The build kept failing and we didn’t know why. We didn’t setup the CI server, nor did we have access to it. Our DevOps guy wasn’t responding (it was 9pm ) so we figured out a way to get info on the Gradle install by just adding this

println """\
This build is using Gradle $gradle.gradleVersion
Gradle home is set toGradle user directory is set to: $gradle.gradleUserHomeDir

Base directory: $projectDir
Running script ${relativePath(buildFile)}
Using JDK: ${org.gradle.api.JavaVersion.current()}
JAVA_HOME: ${System.getenv("JAVA_HOME")}
JVM: ${org.gradle.internal.jvm.Jvm.current()}
"""

About the Author

Mike Hostetler

Principal Technologist

Mike has almost 20 years of experience in technology. He started in networking and Unix administration, and grew into technical support and QA testing. But he has always done some development on the side and decided a few years ago to pursue it full-time. His history of working with users gives Mike a unique perspective on writing software.