How to test void method with Junit testing tools?

java unit-testing junit void
user152462 picture user152462 · Aug 7, 2009 · Viewed 81.9k times · Source

I just happen to implement a method void followlink(obj page,obj link) which simply adds page and link to queue. I have unsuccessfully tried to test this kind of method.

All I want is to test that in the queue contains page and link received from followlink method. My test class already extends TestCase. So what is the best way to test such a method?

Answer

Bill the Lizard picture Bill the Lizard · Aug 7, 2009

The JUnit FAQ has a section on testing methods that return void. In your case, you want to test a side effect of the method called.

The example given in the FAQ tests that the size of a Collection changes after an item is added.

@Test
public void testCollectionAdd() {
    Collection collection = new ArrayList();
    assertEquals(0, collection.size());
    collection.add("itemA");
    assertEquals(1, collection.size());
    collection.add("itemB");
    assertEquals(2, collection.size());
}

Related questions

Mockito : how to verify method was called on an object created within a method?

I am new to Mockito. Given the class below, how can I use Mockito to verify that someMethod was invoked exactly once after foo was invoked? public class Foo { public void foo(){ Bar bar = new Bar(); bar.someMethod(); } } I would …

Read More
How to run test methods in specific order in JUnit4?

I want to execute test methods which are annotated by @Test in specific order. For example: public class MyTest { @Test public void test1(){} @Test public void test2(){} } I want to ensure to run test1() before test2() each time I run …

Read More
Mockito. Verify method arguments

I've googled about this, but didn't find anything relevant. I've got something like this: Object obj = getObject(); Mockeable mock= Mockito.mock(Mockeable.class); Mockito.when(mock.mymethod(obj )).thenReturn(null); Testeable testableObj = new Testeable(); testableObj.setMockeable(mock); command.runtestmethod(); Now, …

Read More