Java 4..11, Kotlin, Code Coverage and their best friend — bytecode: scandals, intrigues, investigations

Do you know what is inside of your class files? Are you ready to bet? Let's have fun by diving into bytecode pattern matching and explore how different compilers (Java/Kotlin) and their different versions, including recently released javac 11, transform your source code.

Our dive will be based on details of implementation of most popular open source code coverage tool for Java — JaCoCo, whose recently released version finds in bytecode and filters out various compiler generated artifacts, which otherwise require unnecessary and sometimes impossible tricks to have full code coverage.