How to Junit test and expect an exception whilst maintaining code coverage

Question

I am trying to write some JUnits for my application, I believe I have got around 80% code coverage, but when i run the tests my report looks as follows;

code coverage

This is giving me a code coverage result of 52% which is not idea.

Is there an alternative way to write the methods in which an exception is expected so as to maintain my coverage score?

Thanks

possible duplicate of [How do you assert that a certain exception is thrown in JUnit 4 tests?](http://stackoverflow.com/questions/156503/how-do-you-assert-that-a-certain-exception-is-thrown-in-junit-4-tests) — DavidPostill, Jul 25 '14 at 11:19
maybe use fail() in JUnit at the end of the try block and every catch block except for that one you're monitoring? — webuster, Jul 25 '14 at 11:38
Why do you want to measure coverage of test classes? You should focus on your regular classes. — Paweł Adamski, Jul 25 '14 at 13:17

score 2 · Accepted Answer · answered Jul 25 '14 at 14:39

Don't worry about code coverage of Tests only the code coverage of the source code (not test code).

If you are using emma or jaCoCo, you can use filters to only instrument or report the results of specific classes or directories.

This is much easier to do if you have separate folders for src and test

score 0 · Answer 2 · edited Jun 20 '20 at 09:12

Probably you are using Eclipse EMMA plugin to measure code coverage. As described here http://emma.sourceforge.net/faq.html#q.blockcoverage Emma measures block (not line) coverage, so when your code throws exception at some point that block is not covered because end of it was not reached. EMMA FAQ says:

block is a sequence of bytecode instructions without any jumps or jump targets. In other words, a basic block always (in the absense of exceptions) executes as one atomic unit (if it is entered at all)

and

A covered basic block is thus guaranteed to have executed without failures at least once in a given coverage run session.

One more thing.
You shouldn't look on coverage of your test classes, focus on business (regular) one.

How to Junit test and expect an exception whilst maintaining code coverage

2 Answers2