Question

I’m using Mockito for my unit testing, and I’ve run across an issue where I have a collection of hashes, and I want to verify that the parameters were equivalent.

i.e. I have something like

Collection< byte[] > blobs = new ArrayList< byte[] >();

// Do some stuff, omitted for brevity

verify( mockStore ).setWhatever( eq( blobs ) );

This fails, since ‘equals()’ on byte[]’s does a reference compare (and it’s not the same reference).

Is there something simple I’m missing to compare two collections of byte[]’s? Is there a special matcher that I need to use for the comparison? Normally I’d use Arrays.equal(), but I don’t know how to tell Mockito to use that for comparing the elements. Suggestions?

Answer 1

There’s no deepEquals mockito matcher. However you could code one in some test helper, for example :

public static Collection<byte[]> sameHashes(Collection<byte[]> hashes) {
    class CollectionOfHashesMatcher extends ArgumentMatcher<Collection<byte[]>> {
        public boolean matches(Collection<byte[] actualListOfHashes) { /* ... */ }        
        public void describeTo(Description description) { /* ... */ }        
    };
    return argThat(new CollectionOfHashesMatcher(hashes));
}

Which should give soemthing like :

verify(mockStore).setWhatever(sameHashes(blobs));