Gradle for Android: Why doesn't javaexec pick up my classpath?

Question

I have an Android project (on Windows) where I am trying to run cucumber-jvm as a non-instrumented "unit test". Ie execute Cucumber features when I run gradlew test .

Here are the relevant bits of my app's build.gradle :

android {
    ...
    testOptions {
        unitTests.all {
            javaexec {
                main = "cucumber.api.cli.Main"
                classpath = getClasspath()
                args = ['--plugin', 'pretty', '--glue', 'gradle.cucumber', 'src/test/java/cucumber/assets']
            }
        }
    }
}
dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:28.0.0-rc02'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    testImplementation 'io.cucumber:cucumber-java:3.0.2'
    testImplementation 'io.cucumber:cucumber-junit:3.0.2'
}

When I run gradlew test --info at the command-line I get the following error:

Starting process 'command 'C:\Program Files\Java\jdk1.8.0_162\bin\java.exe''. Working directory: C:\dev\urig\android-cucumber\app Command: C:\Program Files\Java\jdk1.8.0_162\bin\java.exe -Dfile.encoding=windows-1252 -Duser.country=US -Duser.language=en -Duser.variant cucumber.api.cli.Main --plugin pretty --glue gradle.cucumber src/test/java/cucumber/assets
Successfully started process 'command 'C:\Program Files\Java\jdk1.8.0_162\bin\java.exe''
Error: Could not find or load main class cucumber.api.cli.Main

It looks to me like the command contains no classpath and my question is - Why?

PS - I've verified that at the time of the call to javaexec the call to getClasspath() indeed contains all the dependencies with this little bit of Groovy: println getClasspath().any { println it }

PPS - I know the intended use of cucumber-jvm is for instrumented tests using cucumber-android . I have a specific use case for running Cucumber as a "local unit test" (Android terms, not mine) so the above doesn't quite help me.

Answer 1

I believe I've found a solution for my issue. Here's the code that works for me:

testOptions {
    unitTests.all {
        def classpath2 = getClasspath()
        javaexec {
            main = "cucumber.api.cli.Main"
            classpath = classpath2
            args = ['--plugin', 'pretty', '--glue', 'gradle.cucumber', 'src/test/java/cucumber/assets']
        }
    }
}

It seems to me that my original call to getClassPath() inside the javaexec closure was returning an empty file collection. At the same time, in the closure for unitTests.all , getClassPath() contains the correct classpath.

By passing the classpath from the external closure into the internal closure via a variable, cucumber.api.cli.Main now runs successfully and my Cucumber features run as part of the Gradle test task.