junit arrays not equal test

Question

I'm trying to write a test case where my scenario is that two byte arrays should be not equal.

Can I do this with junit?

Or do I have to use something external like Hamcrest? I couldn't change the code in this answer to do the job

Please give a sample.

Answer 1

I prefer doing this the Hamcrest way, which is more expressive:

Assert.assertThat(array1, IsNot.not(IsEqual.equalTo(array2))); 

Or the short version with static imports:

assertThat(array1, not(equalTo(array2))); 

(The IsEqual matcher is smart enough to understand arrays, fortunately.)

Note that a limited version of Hamcrest is part of the JUnit 4.x distribution, so you don't need to add an external library.

Answer 2

You can use

assertFalse(Arrays.equals(array1, array2)); 

If you wanted to check they were equal, I would use the following instead.

assertEquals(Arrays.toString(array1), Arrays.toString(array2)); 

as this produces a readable output as to what was different rather than just failing.