Why does Mockito skip tests when I use a large array?

Question

I have the following test which I am trying to run through Mockito(in a Spring Boot Project):

@ExtendWith(MockitoExtension.class)
public class TestClass {

    @Test
    void arrayTest() {
        int arrSize = Integer.MAX_VALUE;
        Integer[] arr = new Integer[arrSize];

        for (int index = 0; index < arr.length; index += 1000) {
            for (int j = index; j < Math.min(index + 1000, arr.length); j++) {
                arr[j] = 500;
            }
        }

        Assertions.assertEquals(arrSize, arr.length);
    }
}

Pretty simple test just takes an array and sets its values to an integer number.

But when I run this test though IntelliJ I get the following output in the GUI:

When I change arrSize to lets say 10. The test works as its suppose to.

What is going on here ?

Why is Mockito skipping the test ? It should give me an OOM error correct ? Not skip the test.

Is anyone else getting the same behaviour with a similar test ?

Thanks

It seems to be an OOM issue looking at the verbose logs:

The problem still happens with different objects:

@Test
    void arrayTest() {
        int arrSize = 1_00_00_000;
        Map[] arr = new Map[arrSize];

        for (int index = 0; index < arr.length; index += 1000) {
            for (int j = index; j < Math.min(index + 1000, arr.length); j++) {
                arr[j] = new HashMap();
            }
        }
        Assertions.assertEquals(arrSize, arr.length);
    }

Answer 1

Send console output of arrayTest(). I think that it's because you use Integer.MAX_VALUE and it has value 2147483647. So last value in-work is 2147483000 and next 2147484000 is already out of int type size. So index variable just cannot be assigned to this value.

So

• Do not use iteration step 1000, any value in iteration shouldn't be greater then Integer.MAX_VALUE.
• Use any other max value less or equals 2147483000

Edit after adding OutOfMemoryException trace in the question:

You have no RAM memory resources to allocate array of this size. 2147483647 * 4 bytes = 8.6 GB RAM memory