Combine reports from existing Gradle reports

Alternatively, you can merge Gradle unit test HTML reports for all subprojects into a single index.html file placing the following in your root build.gradle file.

task testReport(type: TestReport) {
  destinationDir = file("$buildDir/reports/allTests")
  // Combine all 'test' task results into a single HTML report
  reportOn subprojects.collect { it.tasks.withType(Test) }
}

This results should be available at build/reports/allTests/index.html