Missing coverage for Kotlin suspend functions calling reactor WebClient.ResponseSpec.awaitBody()

[btpnlsl]

Steps to reproduce

• JaCoCo version: 0.8.8.202204050719
• Operating system: Windows 11 Pro version 10.0.22621 Build 22621
• Tool integration: Maven
• Complete executable reproducer: https://github.com/wlogan-omnidian/jacoco-webclient-bug
• Steps:
  mvn clean verify
mvn jacoco:report

Expected behaviour

Full test coverage for Kotlin suspend functions which are calling WebClient.awaitBody()

Actual behaviour

JaCoCo appears to mistakenly mark certain Kotlin suspend functions as not fully covered by tests, but only when they call WebClient.awaitBody(). This sample shows this behaviour. When built and run with mvn verify, the JaCoCo coverage report will show that doLocalWork() is fully covered, but doWebWork() is not. The first line of doWebWork() will show partial coverage.

(In case of exceptions provide FULL STACKTRACE)

[wlogan-omnidian]

I think this has something to do with .awaitBody<T>() being declared as suspend inline fun <reified T : Any>. Replacing the call to .awaitBody<T>() with its reified expansion (in the case of this repro code, .bodyToMono<String>().awaitSingle()) side-steps the issue, and JaCoCo gives accurate coverage results. It looks like the "impossible branch" in the inlined code is being treated as a legitimate branch for coverage purposes.

I've added an additional test case to the repro demonstrating this: .doWebWork2() shows full coverage, while .doWebWork() still shows a missed instruction.