Code in module B does not show as covered when tested from module A?

[Rolf Smit]

I hope someone can help me with the following problem:

(I know my project uses the Jacoco Gradle plugin and this mail group is only for Jacoco, but maybe I'm just doing something wrong regarding Jacoco in general)

Environment:

An Android project that uses Jacoco (through Gradle), this project has both normal unit tests and integration tests using the Android Instrumented Runner.

I have two modules:

• Module A contains tests (both unit tests and android instrumented tests) some of these tests touch code in module B
• Module B contains tests (both unit tests and android instrumented tests), it also contains code that is only touched by tests in module A

Module A depends on module B.

I configured Jacoco to use multiple `.exec` files, 4 in total:

• Module A .exec file from the unit tests
• Module A .exec file from the android instrumented tests (downloaded from device)
• Module B .exec file from the unit tests
• Module B .exec file from the android instrumented tests (downloaded from device)

I also made sure Jacoco uses all class files (from both modules) and all sources (from both modules)

I tried Jacoco : 8.2, 8.4 and 8.5

Result:

• Code in module A, touched by unit tests in module A show as covered ✔
• Code in module A, touched by android instrumented tests in module A show as covered ✔
• Code in module B, touched by unit tests in module B show as covered ✔
• Code in module B, touched by android instrumented tests in module B show as covered ✔

aggregate expectations:

• Code in module B, touched by unit tests in module A show as covered ❌
• Code in module B, touched by android instrumented tests in module A show as covered ✔

Notice how "touchedByUnitTestInConsumer()" is not covered even though the test reaches this code (I tested this by adding an exception).

Expected result:

• Code in module B, touched by unit tests in module A show as covered ✔

The problem:

Everything seems to work except for code in module B that is touched by unit tests in module A, that code does not show up as "covered". Which I find weird because it does work for the "android instrumented tests".


Things I tried:

I tried to instead of configuring Jacoco to use multiple .exec files to merge the files into one file before feeding it into Jacoco, but the report didn't show any difference. I also tried to use the append option to append everything into one .exec files.

Is Jacoco even supposed to show code as covered when it is touched by tests in another module?

Logging also seems to suggest that Jacoco is configured correctly (I have indeed 4 sources classes, 2 in module A and 2 in module B, I also have 4 .[ex]ec files):

[ant:jacocoReport] Loading execution data file *\multi-module\app\build\jacoco\testDebugUnitTest.exec                

[ant:jacocoReport] Loading execution data file *\multi-module\app\build\outputs\code_coverage\debugAndroidTest\connected\Pixel_2_API_27(AVD) - 8.1.0-coverage.ec                      

[ant:jacocoReport] Loading execution data file *\multi-module\library_android\build\jacoco\testDebugUnitTest.exec                 

[ant:jacocoReport] Loading execution data file *\multi-module\library_android\build\outputs\code_coverage\debugAndroidTest\connected\Pixel_2_API_27(AVD) - 8.1.0-coverage.ec                       

[ant:jacocoReport] Writing bundle 'multi-module' with 4 classes      

Sample project:

I have a sample project: https://github.com/NeoTech-Software/Android-Root-Coverage-Plugin/tree/bug/unit-test-a-no-coverage-in-b

My project is a Gradle Plugin that takes away most of the boilerplate code that is needed to configure Jacoco for Android projects. However I added a few extra tests to confirm everything really works, you can find these tests in branch bug/unit-test-a-no-coverage-in-b the tests in this branch fail due to the problem I described.


Who can shed some light on this? Thanks!