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Naming convention for methods with JUnit

Andrew Romanenco

Joined: Feb 28, 2006
Posts: 5

Could you share your experience how do you (your company) test code?
We are using JUnit 4, and we have naming convention for all test methods.

after annotation @Test, we give each method name

and so on

but sometimes we have to make more then one test case for one method.

For example: we want to test makeSearch(...) with different parameters.

We have two possible solutions:
1. put all checks in one method, like:
public testMakeSearch() {

2. make one test method for each case

Variant 1 is not too good, as we will not see what cases are ok - we will see fail after first fail.

Variant 2 is better, but I don't know which naming convention to use...


but as I know "_" is not recommended in names (but not resticted)

how do you resolve this?

Stan James
(instanceof Sidekick)
Ranch Hand

Joined: Jan 29, 2003
Posts: 8791
Hmmm, I often name mine after the input or expected result. testTooLarge() testTooSmall() testWithPunctuation(). Can't say I have a convention.

A good question is never answered. It is not a bolt to be tightened into place but a seed to be planted and to bear more seed toward the hope of greening the landscape of the idea. John Ciardi
Andrew Romanenco

Joined: Feb 28, 2006
Posts: 5
Naming with case description is good for small classes. On fail it is 100% where the problem is.
But it will be hard to get code coverage...
Ilja Preuss

Joined: Jul 11, 2001
Posts: 14112
Frankly, I think that convention is far from optimal.

First, the test-prefix is redundant. The annotation already communicates that it is a test method. So why repeat that in the method name?

Second, and more importantly, in my opinion you shouldn't think about it as testing methods at all, you should think about it as testing behavior of the class. Consequently, I like my test method names to communicate the expected behavior.

So names of test methods that I would be likely to use could include

searchAfterResetFindsFirstHitAgain (or resetClearsCriteria or whatever reset is actually supposed to do)

etc. pp.

The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus
Cedric Beust
Ranch Hand

Joined: Oct 12, 2004
Posts: 46
Hi Andrew,

You can easily pass parameters to your test methods with TestNG's Data Providers, which I described in this thread:

Once you can pass parameters to your test methods, nothing stops you from overloading the same method name several times with different signatures...

Lasse Koskela

Joined: Jan 23, 2002
Posts: 11962
I tend to describe the behavior I'm verifying in the name of my tests, e.g. "fooShouldBarWhenWhizGoesBang()" or "fooTellsAllBarsToCloseTooEarly()".

Sometimes I also do something like this:

That is, I name the test class according to the fixture set up with the @Before method. For example, above we have a cluster of three nodes so I name the test class like that - (Test)ClusterOfThreeNodes. The test methods, on the other hand, read out as statements about the system's behavior in the state described by the fixture (and the class name). For example, "loadBalancesBetweenAllThreeNodesUsingRoundRobin()".

So when I look at a test class, I mentally parse the class and method names as "ClusterOfThreeNodes.loadBalancesBetweenAllThreeNodesUsingRoundRobin".

Author of Test Driven (2007) and Effective Unit Testing (2013) [Blog] [HowToAskQuestionsOnJavaRanch]
I agree. Here's the link:
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