Codecoverage with Jacoco fails

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Hi

I am running into issues using the coverall maven plugin, together with jacoco reports on Kotlin files.

My understanding of what happens is quite limited and based on guess work. From what I understand the class files produced by Kotlin seem to be “not strict enough” in their debug data for jacoco… whatever that means.

Basically jacoco is reporting a source file line number that is greater than the source file, which results in an exception text like this:

[ERROR] Failed to execute goal org.eluder.coveralls:coveralls-maven-plugin:4.1.0:report (default-cli) on project BinaryDataParser: Build error: Line number 91 is greater than the source file bdp-processor/src/main/java/org/ak80/bdp/MappedClass.kt size → [Help 1]

It seems similiar (same?) problems have been experienced with jacoco+coverall+scala, see for example: Line number N is greater than the source file X size · Issue #98 · trautonen/coveralls-maven-plugin · GitHub

I really would like to get code coverage reports… Is there anything I can do to get this working? Is there maybe an issue I can help with?

I really love to work with Kotlin, and this is the first and only mishap I had so far. Would be great to get it sorted out.

Thanks and with regards
Alex

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Anyone got any idea on how to either start understanding what goes wrong and how it could be fixed or who could help with this please?

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The Kotlin compiler uses line numbers beyond the file length to denote inlined functions. It has to do that as java debug information only allows specifying a single source file per class. I haven’t checked it, but I suspect that the compiler also injects a nonstandard section with the additional mapping information. The Kotlin tools then use the combination to revert to a true file:line combination for the code. For a coverage checker you would have to make it aware of the section or at least make it not crash on out of bounds line numbers.

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Thank you for taking the time to reply. This helps a lot for understanding how to approach this, although I feel this is to big a challenge for me… Anyway, I appreciate your reply and wish a happy new year