Cobertura not generating coverage report - gradle

Question

I am trying to use cobertura to generate coverage report for my groovy project. I am using gradle to install cobertura ang junit 5
plugins {
id 'java'
id 'groovy'
id 'net.saliman.cobertura' version '2.5.4'
}
dependencies {
implementation 'org.codehaus.groovy:groovy-all:2.4.0'
testImplementation 'org.junit.jupiter:junit-jupiter-api:5.3.1'
testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.3.1'
}
test {
useJUnitPlatform()
}
Running the cobertura task generates an empty coverage report (0 classes and no coverage). The jUnit report shows the correct unit test which have been run.
Gralde output
> Task :coberturaReport UP-TO-DATE
> Task :compileJava NO-SOURCE
> Task :compileGroovy
> Task :processResources NO-SOURCE
> Task :classes
> Task :instrument
Cobertura 2.1.1 - GNU GPL License (NO WARRANTY) - See COPYRIGHT file
> Task :copyCoberturaDatafile
> Task :compileTestJava NO-SOURCE
> Task :compileTestGroovy
> Task :processTestResources NO-SOURCE
> Task :testClasses
> Task :test
> Task :generateCoberturaReport
Cobertura 2.1.1 - GNU GPL License (NO WARRANTY) - See COPYRIGHT file
Report time: 150ms
> Task :performCoverageCheck SKIPPED
> Task :cobertura
BUILD SUCCESSFUL in 11s
6 actionable tasks: 6 executed
07:53:16: Task execution finished 'cobertura'.
What confuses me is the line > Task :performCoverageCheck SKIPPED Is this the problem? How do I enable the coverage check?

Answer 1

After enabling --debug, I found that it is not instrumenting any classes. Adding coverageDirs = ["${buildDir}/classes/groovy/main"] in cobertura as below solved the issues for me.
cobertura {
coverageFormats = ["html", "xml"]
coverageIgnoreTrivial true
coverageCheckHaltOnFailure false
coverageDirs = ["${buildDir}/classes/groovy/main"]
}