Improve unit test coverage

[yruslan]

• Ensure all code on the critical execution path is covered by unit tests
• Move supplementary code including examples and test data generators into a separate project so it won't interfere with the main code

[tr11]

What tool are you using to report the unit test coverage? I can definitely help with the code paths related to the parser.

[yruslan]

We use scoverage Maven plugin as a primary unit test coverage report tool and IntelliJ's coverage capabilities as a secondary tool.

mvn scoverage:check
mvn scoverage:report