Kover CLI report generation does not reliably with --excludeAnnotation when using JAR (instead of folder) for --classfiles

[oliviernotteghem]

We found instances where, when using --classfiles to point to a JAR, --excludeAnnotation does not work completely and some code that should be excluded still appear to be covered.

With the same command line have --classfiles pointing to a folder, when the JAR was unpacked, the filtering works reliably.

Example of command line invocation :
java -jar /Users/oliviern/.devxp/import-cache/4b81c0960d39ddd828f97e31aee273bf0d929d87/3c34899b72c05e31efaa6ed042ad0527573034a1/kover-cli-0.8.2.jar @bazel-bin/libraries/foundation/ui/ui-compose-ambients/test_release-kover_metadata.txt --xml bazel-bin/libraries/foundation/ui/ui-compose-ambients/test_release-kover_report.xml --html /Users/oliviern/Uber/android/bazel-testlogs/libraries/foundation/ui/ui-compose-ambients/test_release/coverage_report

content of bazel-bin/libraries/foundation/ui/ui-compose-ambients/test_release-kover_metadata.txt:

report
bazel-out/xplat-fastbuild/bin/libraries/foundation/ui/ui-compose-ambients/test_release-kover_report.ic
--title
Code-Coverage Analysis: @@//libraries/foundation/ui/ui-compose-ambients:test_release
--src
libraries/foundation/ui/ui-compose-ambients/src/main/kotlin/com/uber/ui/compose/core/ambient
--classfiles
bazel-out/xplat-fastbuild/bin/libraries/foundation/ui/ui-compose-ambients/libsrc_release.jar
--exclude
*Expose

example of code failing to be filtered out:

  @Expose
  fun composeDeps(
      analyticsClient: AnalyticsClient,
  ) =
      object : composeDependencies {
        override fun analyticsClient() = analyticsClient
      }

[zuevmaxim]

@oliviernotteghem Could you please look into the bytecode of the class inside jar, and check that the annotation is present there?
Unpack the jar, and then use javap -v -l -p <path-to-class>.class to see the bytecode. The target method should have the annotation.
While testing, I found out that ProGuard removed RetentionPolicy.CLASS annotation in my case, maybe it is something similar in your case

[oliviernotteghem]

@zuevmaxim : I forgot to mention that we verified this already. The annotation is not stripped and is present in bytecode.

[shanshin]

@oliviernotteghem, to reproduce it locally we need reproducer project or a problematic jar file

[oliviernotteghem]

Sure. Here is problematic jar
src_main.jar.zip and .ic file
test_main-kover_report.ic.zip

The code corresponds to the screenshot below.

During report generation, we use --excludeAnnotation *Expose, however you can it worked on expose() method, but not for the code in composeDeps()

[shanshin]

Thanks for the reproducer.
This is a specific of the current implementation, anonymous objects are compiled as nested classes, and they are included in the report as a separate class, so it must be excluded separately.

Try this way

@Expose
fun composeDeps(
) =  
  @Expose object : composeDependencies {
       // ... 
    } 

*I understand that the Expose annotation is intended for another, so for such cases, you can add another one.

[oliviernotteghem]

@shanshin how would you explain filtering works when --classfiles points to a folder (containing unpacked JAR) instead of the JAR itself?

[shanshin]

Fixed in 0.9.0

[oliviernotteghem]

Thank you very much. We upgraded to 0.9.0 and can confirm the issue is gone. There seems to be other fixes as well as our code coverage for failing module is not non-null, which materializes into a nice code coverage increase for Uber android monorepo :)