README.md

Bug Description

Scala 3 macros seem to cause scoverage to fail to produce correct coverage reports.

The code is structured as follows:

.
└── org
    └── example
        ├── App.scala
        ├── NumUtils.scala
        ├── greeting
        │   └── Greeting.scala
        └── macros
            └── Macros.scala

The key points are:

• Greeting.scala defines the logic to greet users (greet: Option[String] => String);
• Macros.scala defines a macro to decorate strings at compile time (decorate: String => String);
• App.scala greets an undefined user and decorates a string using the macro (println(decorate(greet(None))));
• NumUtils.scala defines a simple function isEven which is completely unrelated to the rest of the code.

The coverage report fails to include Greeting.scala, Macros.scala, and NumUtils.scala. Moreover, it shows 100% coverage for App.scala even though it should be 0% (main method is never called in the tests).

Steps to Reproduce

sbt clean
sbt coverage test
sbt coverageReport

To make sure that macros are the cause of the issue, simply make the decorate macro into regular method:

def decorate(s: String): String = s">>> $s <<<"

and re-run tests and report generation. Coverage is now correctly computed.