IssueTracker

If I set testCoverageEnabled to true in the build.gradle for a library module in a multi-module Android project, then the .exec file generated for running unit tests is nearly empty, and any reports generated from it will show 0% code coverage.

Setting testCoverageEnabled to false results in a much larger .exec file that displays the proper coverage in generated reports. (however, testCoverageEnabled is required so that I can use these binaries to gather coverage numbers for on-device instrumentation tests)

Sample:

• https://github.com/Aidan128/JacocoFailureExample

Environment:

• JaCoCo 0.8.7
• MacOS 11.6 (Big Sur)
• Gradle 7.0.1

Steps:

1. Create multi-module Android application
2. In build.gradle for both the application module and a library module, add

plugins {
   ...
   id 'jacoco'
}

jacoco {
    toolVersion '0.8.7'
}

3. From the command line, navigate into each module and execute ../gradlew clean testDebugUnitTest
4. Note that the generated .exec files for each module (build/jacoco/testDebugUnitTest.exec) are each ~27k in size.
5. Now add the additional content to each module's build.gradle

android {
    ...
    buildTypes {
        debug {
            testCoverageEnabled true
        }
       ...
    }
}

6. Again, from the command line, navigate into each module and execute ../gradlew clean testDebugUnitTest
7. Note that the generated .exec file for the application module (build/outputs/unit_test_code_coverage/debugUnitTest/testDebugUnitTest.exec) is still ~27k in size, but the generated .exec file for the library module (build/outputs/unit_test_code_coverage/debugUnitTest/testDebugUnitTest.exec) is only 45 bytes long.
8. Finally, in each module's build.gradle, set testCoverageEnabled to false.
9. From the command line, navigate into each module and execute

../gradlew clean testDebugUnitTest

10. Note that the generated .exec files for each module (build/jacoco/testDebugUnitTest.exec) are again each ~27k in size.