patch-diff-report-tool: Add tests and code coverage

[rnveach]

We should start adding tests and coverage to make sure utility is stable as we are using it more and more.

[romani]

please do not be crazy with over testing.

If that is required , it is already sign that tool need to be written in java and have complete set of validations. We did this tool on groovy only to be a bit more user friendly (not a shell) and keep simple (script like). In all my experience with groovy, any investment in complicated groovy will result in high cost of support. As you grow script it should become multi-file , so not a script any more so need to be compiled , so..... become the same as java.

As I told you in other issue, it is enough to keep in CI full run with recheck of expected output.

[rnveach]

@romani

need to be written in java .... We did this tool on groovy only

I think you are confusing what tool I am talking about here. patch-diff-report-tool is already in Java, not groovy. I am not talking about making tests for groovy scripts here.

[romani]

yes, my bad. tests for java diff tool is ok.