I noticed that JaCoCo does not include in the coverage report Groovy 3 lambdas (contrary to closures).
After asking on the JaCoCo group, the JaCoCo maintainer suggested me to ask on the Groovy side.
The problem is that the generated class for lambda is marked as synthetic, which is not the case for the closure class.
Here is a full discussion: https://groups.google.com/g/jacoco/c/MR4mrJB-kVE
Is it possible to remove that synthetic modifier?