Recently, I was given an opportunity to increase the code coverage in a project based on Java Swing, MySQL and other technologies. They told me to bring the code coverage to 100%, while it was only 45% at the time I joined.

I am just starting, not a professional developer, right from the beginning I felt bad even though I write and understand computer programs well.

(The developed code contains a lot of technical stuff like Generics and no documentation about the code is available.)

Has anyone experienced the same situation before?

Please tell who is the right person to do the job.