Can I make JUnit more verbose?

Question

I\'d like to have it yell hooray whenever an assert statement succeeds, or at the very least have it display the number of successful assert statements that were encountered

Answer 1

You can use AOP (with Spring or AspectJ) define pointcuts on all assert methods in junit.framework.Assert class. Using spring you can implement your own class as after returning advice (http://static.springframework.org/spring/docs/2.5.x/reference/aop.html#aop-advice-after-returning) which will only be called if the assert method passed (otherwise it throws an exception: junit.framework.AssertionFailedError ). In you own class you can implement a simple counter and print it at the end.

Answer 2

If you want to see some output for each successful assertion, another simple approach which requires no external dependencies or source code, would be to define your own Assert class which delegates all methods to the standard JUnit Assert class, as well as logging successful assertions (failed assertions will be reported as usual by the JUnit class).

You then run a global search-and-replace on your test classes from "org.junit.Assert" => "com.myco.test.Assert", which should fix-up all regular and static import statements.

You could also then easily migrate your approach to the quieter-is-better-camp and change the wrapper class to just report the total # of passed assertions per test or per class, etc.

Answer 3

Adding some info that would have been helpful to me when I wanted JUnit to be more verbose and stumbled on this question. Maybe it will help other testers in the future.

If you are running JUnit from Ant, and want to see what tests are being run, you can add the following to your task:

<junit showoutput="true" printsummary="on" enabletestlistenerevents="true" fork="@{fork}" forkmode="once" haltonfailure="no" timeout="1800000">

Note that showoutput, printsummary, and enabletestlistenerevents are what helped, not the other task attributes. If you set these, you'll get output like:

Running com.foo.bar.MyTest
junit.framework.TestListener: tests to run: 2
junit.framework.TestListener: startTest(myTestOne)
junit.framework.TestListener: endTest(myTestOne)
junit.framework.TestListener: startTest(myTestTwo)
junit.framework.TestListener: endTest(myTestTwo)
Tests run: 2, Failures: 0, Errors: 0, Time elapsed: 0.495 sec

This was useful to me when my tests were timing out and I wasn't sure which tests were actually taking too long, and which tests got cancelled because they were unlucky enough to be running when the time was up.

Answer 4

I'm pretty sure you can create a custom TestRunner that does that. We ended up with something similar in our homemade Unit-testing framework (a clone of NUnit).

Oh, wait - now that I'm reading your question again, if you really want output for each successful assertion, you'll have to dig into the plumbing more. The TestRunner only gets called once for each testcase start/end, so it'll count passed and failed tests, not assertions.

This isn't much of a problem for me, since I tend towards one assertion per test, generally.

Answer 5

This is not a straight answer to the question and is in fact a misuse of a junit feature, but if you need to debug some values that are used in the asserts, then you can add temporarily something like:

Assume.assumeTrue(interestingData, false);

This won't fail the build, but will mark the test as IGNORED, and will force the values to be included in the test report output.

❗️ Make sure to remove the statements once you are done. Or, as an alternative, you can change the statement to Assume.assumeTrue(interestingData, true) in case you might want to debug it again in the future.

Answer 6

Can you consider ?

1) download junit source
2) to modify the class org.junit.Assert to do whatever modifications you're looking for