Junit assert OR condition in my test case

Question

In my test case, I get an integer value:

int val = getXXX();

Then, I would like to check if val either equals to 3 or equals to 5 which is OK in either case. So, I did:

assertTrue(val == 3 || val==5);

I run my test, the log shows val is 5, but my above assertion code failed with AssertionFailedError. Seems I can not use assertTrue(...) in this way, then, how to check true for OR condition?

Answer 1

ive tried to write quick test:

@Test
public void testName() {
    int i = 5;
    junit.framework.Assert.assertTrue(i == 3 || i == 5);

}

its passing always so i guess there is some inbetween code when your value is changed. You can use

org.junit.Assert.assertEquals(5, i);

to check value - this assertion will print out nice info whats wrong, for example:

java.lang.AssertionError: 
Expected :4
Actual   :5

Answer 2

You can use Hamcrest matchers to get a clearer error message here:

int i = 2;
assertThat(i, Matchers.either(Matchers.is(3)).or(Matchers.is(5))

or

int i = 2;
assertThat(i, Matchers.anyOf(Matchers.is(3),Matchers.is(5)));

This will more clearly explain:

Expected: (is <3> or is <5>)
     but: was <2>

showing exactly the expectation and the incorrect value that was provided.

Answer 3

While Harmcrest matchers can do the job, these constants can be easily refactored to a more meaninful constant, like a list of valid values. Then you can use the contains method to check that the value is present in the list - IMO is also easier to read:

public class Foo {
    public static final List<Integer> VALID_VALUES = Arrays.asList(3, 5);
}

@Test
public void testName() {
    int i = 5;
    Assert.assertTrue(Foo.VALID_VALUES.contains(i));
}

Answer 4

In my case I wanted to do some complex assertion logic, so I simply implemented a method that returns a boolean and it did the job, the way it would be implemented in this example is as follows:

private Boolean is3or5(Integer val) {
    if(val == 3 || val == 5) {
        return true;
    }
    return false;
}

Then do the assertion:

assertTrue(is3or5(val));

Of course the method can contain more complex logic if needed