Compare two sets of a class without equals

Question

I have a class Something:

public class Something {
   public String a;
   public String b;
}

Suppose I can't write equals or compare method in class Something.

My test:

Set<Something> aSet;
Set<Something> otherSet;

assertEquals(aSet, otherSet);//Fails because it only compares references of elements and does not perform a deep comparision field by field

Is there any way to assert if both sets are equals comparing elements field by field (without writing equals method in Something class)?

Answer 1

Give a try to AssertJ, it provides a way to compare element field by field recursively, example:

// the Dude class does not override equals
Dude jon = new Dude("Jon", 1.2);
Dude sam = new Dude("Sam", 1.3);
jon.friend = sam;
sam.friend = jon;

Dude jonClone = new Dude("Jon", 1.2);
Dude samClone = new Dude("Sam", 1.3);
jonClone.friend = samClone;
samClone.friend = jonClone;

assertThat(asList(jon, sam)).usingRecursiveFieldByFieldElementComparator()
                            .contains(jonClone, samClone);

Another possibility is to compare collections using a specific element comparator so SomethingComparator in your case, this requires a bit more work than the first option but you have full control of the comparison.

Hope it helps!