How can I run (or change the order of) specific test-methods in a JUnit test class?

Question

I am fairly new to Java. I have constructed a single JUnit test class and inside this file are a number of test methods. When I run this class (in NetBeans) it runs each test method in the class in order.

Question 1: How can I run only a specific sub-set of the test methods in this class? (Potential answer: Write @Ignore above @Test for the tests I wish to ignore. However, if I want to indicate which test methods I want to run rather than those I want to ignore, is there a more convenient way of doing this?)

Question 2: Is there an easy way to change the order in which the various test methods are run?

Thanks.

Why does the order matter? Each unit test should be able to run in isolation. — dom farr, Jan 10 '11 at 17:16
It is generally a test smell to depend on the order of execution, tests should be stateless. — Gabriel Ščerbák, Jan 10 '11 at 17:23
@dom farr: Perhaps I am doing something wrong but I wanted to test whether changing the order of the test method calls resulted in any problems/bugs. — kmccoy, Jan 10 '11 at 17:24
@K McCoy. Your tests are cause bugs? I would suggest creating a set of tests that describe the behaviour your want, and then complete the code so you only get passing tests. — dom farr, Jan 10 '11 at 17:28

Lukasz · Accepted Answer · 2011-01-10T17:55:50.687

6

You should read about TestSuite's. They allow to group & order your unit test methods. Here's an extract form this article

"JUnit test classes can be rolled up to run in a specific order by creating a Test Suite.

EDIT: Here's an example showing how simple it is:

 public static Test suite() { 
      TestSuite suite = new TestSuite("Sample Tests");

      suite.addTest(new SampleTest("testmethod3"));
      suite.addTest(new SampleTest("testmethod5"));

      return suite; 
 }

edited Jan 10 '11 at 17:55

answered Jan 10 '11 at 17:15

Lukasz

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Your example would run all the test methods in SampleTest.class. However, what if in SampleTest.class I have various test methods [testmethod1(), testmethod2(),...] and I only with to run testmethod3() and testmethod5(); would this be possible? – kmccoy Jan 10 '11 at 17:46
1

@K McCoy: I've edited my example to match your requirements:) – Lukasz Jan 10 '11 at 17:57
1

I have tested the above code and noted two things: (1) The first line should read: public static TestSuite suite() { (2) Inside the class SampleTest one needs to define the constructor public SampleTest (String name) { super(name); } Otherwise, this did the trick for me. Thanks! – kmccoy Jan 14 '11 at 16:19
1

I have tried to execute the above code but I get "The constructor SampleTest(String) is undefined". Is there something I'm missing here? I also read that [running test methods of the same test class in a sequential order was not possible](http://stackoverflow.com/questions/8518314/selenium-junit-tests-how-do-i-run-tests-within-a-test-in-sequential-order) so I'd be very happy if you could help me out on that – Adriano Sep 10 '12 at 21:32

score 2 · Answer 2 · edited May 23 '17 at 12:13

This answer tells you how to do it. Randomizing the order the tests run is a good idea!

Like the comment from dom farr states, each unit test should be able to run in isolation. There should be no residuals and no given requirements after or before a test run. All your unit tests should pass run in any order, or any subset.

It's not a terrible idea to have or generate a map of Test Case --> List of Test and then randomly execute all the tests.

score 0 · Answer 3 · answered Jan 10 '11 at 17:21

There are a number of approaches to this, but it depends on your specific needs. For example, you could split up each of your test methods into separate test classes, and then arrange them in different test suites (which would allow for overlap of methods in the suites if desired). Or, a simpler solution would be to make your test methods normal class methods with one test method in your class that calls them in your specific order. Do you want them to be dynamcially called?

score 0 · Answer 4 · answered Jan 10 '11 at 17:32

I've not been using Java that long either, but as far as I've seen there isn't a convenient method of marking methods to execute rather than ignore. Instead I think this could be achieved using the IDE. When I want to do that in Eclipse I can use the junit view to run individual tests by clicking on them. I imagine there is something similar in Netbeans.

I don't know of an easy way to reorder the test execution. Eclipse has a button to rerun tests with the failing tests first, but it sounds like you want something more versatile.

How can I run (or change the order of) specific test-methods in a JUnit test class?

4 Answers4