Why isn't this statement marked as completely covered by eclemma?

Question

I am using EclEmma in Eclipse (more specifically, RSA 8). I have the following statement in my code:

public static boolean isEmpty(Collection collection) {
    return (collection == null) || collection.isEmpty();
}

and I have the following tests:

@Test public void isEmpty_nullCase() {
    assertTrue(CollectionUtil.isEmpty(null));
}
@Test public void isEmpty_listCase() {
    assertTrue(CollectionUtil.isEmpty(new ArrayList()));
}

but for some reason, the statement is showing up as yellow. What part of it am I not testing?

Thanks, Peter

Answer 1

How about an ArrayList that has a value, and is therefore not empty?

Answer 2

Add the following test case:

@Test
public void checkNonNullNonEmpty(){
   Assert.assertFalse(CollectionUtil.isEmpty(new ArrayList<String>(){
    {
      add("blah blah blah....!");
    }
  });
}

You have only tested true conditions. Ideally there are 4 possible combinations of return (collection == null) || collection.isEmpty(); statement. 1st condition can be T/F and 2nd can be T/F. So totall 4 possibilities. You have covered 3 only. The above test case will cover non null non empty possibility.