Why my Spock unit tests fail in Gradle build after upgrading to JDK 8? - unit-testing

Question

I'm trying to compile my application source using JDK 8, Groovy 2.4.4, Spock 1.0-groovy-2.4, Gradle 1.11 (my firm hass custom plugins built on top of this)
gradle -version
Groovy: 1.8.6
Ant: Apache Ant(TM) version 1.9.2 compiled on July 8 2013
Ivy: 2.2.0
JVM: 1.7.0_51 (Oracle Corporation 24.51-b03)
OS: Windows 7 6.1 amd64
In my build environment, I need to retain my JAVA_HOME to Java 7 for other projects.
JAVA_HOME = C:\Program Files\Java\jdk1.7.0_51
JAVA8_HOME = C:\Program Files\Java\jdk1.8.0_60
Due to this, in my build.gradle, I explicitly tell Gradle to use JDK 8
tasks.withType(JavaCompile) {
options.fork = true;
options.forkOptions.executable = "${System.env.JAVA8_HOME}/bin/javac"
}
tasks.withType(Test) {
executable = "${System.env.JAVA8_HOME}/bin/java"
}
compileJava{
sourceCompatibility = 1.8
targetCompatibility = 1.8
}
The source files compile successfully, however when it reached unit tests (written in Spock), it fails with the below error.
Caused by: java.lang.UnsupportedClassVersionError: org/model/SDA : Unsupported major.minor version 52.0
I confirmed that SDA.class is compiled using JDK 8.
javap -verbose SDA.class | findstr "major"
major version: 52
Any reason why only during unit tests I get the above error? Does that mean unit test is being run on JDK 7?

Answer 1

So if you're really into hacks there is something you can do. It does involve overriding some of the Gradle internals - so it may not work on any version of Gradle other than 1.11. There may also be unexpected side-effects.
import org.gradle.internal.Factory
import org.gradle.process.internal.WorkerProcessBuilder
import org.gradle.api.internal.tasks.compile.daemon.CompilerDaemonStarter
tasks.withType(GroovyCompile) {
options.fork = true
options.forkOptions.executable = "${System.env.JAVA8_HOME}/bin/javac"
doFirst {
def compilerFactory = compiler.compiler.compilerFactory
def clientsManager = compilerFactory.compilerDaemonManager.clientsManager
def oldDaemonStarter = clientsManager.compilerDaemonStarter
if (!(oldDaemonStarter.workerFactory instanceof CustomWorkerProcessFactory)) {
println "HACK, installing custom daemon worker"
clientsManager.compilerDaemonStarter = new CompilerDaemonStarter(
new CustomWorkerProcessFactory(oldDaemonStarter.workerFactory),
oldDaemonStarter.startParameter)
}
}
}
class CustomWorkerProcessFactory implements Factory<WorkerProcessBuilder> {
Factory<WorkerProcessBuilder> delegate
CustomWorkerProcessFactory(Factory<WorkerProcessBuilder> delegate) {
this.delegate = delegate
}
public WorkerProcessBuilder create() {
def newWorker = delegate.create()
newWorker.javaCommand.executable("${System.env.JAVA8_HOME}/bin/java")
newWorker
}
}

Answer 2

Add this to your gradle.properties:
org.gradle.java.home=/path/to/java8
Or when you launch gradle, you can specify it as a jvm parameter:
gradle -Dorg.gradle.java.home=/path/to/java8 task1 task2