assertj / Java comparing objects with list field ignoring order of elements in list

Question

I am looking to compare 2 list of objects (say Foo) in test.

List<Foo> fooA;
List<Foo> fooB;

Each Foo entry has one of the fields of type List (say Bar)

class Foo {
  private List<Bar> bars;
  ....
}

assertThat(fooA).isEqualTo(fooB);

Comparison fails because elements of bars are same but in different order.

Is there a way to compare them ignoring order?

I am not looking for below option.

assertThat(fooA).usingElementComparatorIgnoringFields("bars").isEqualTo(fooB);

Ideally I would like to compare all the fields

The comparison would fail even if the items were in the same order because the 2 lists are 2 different objects. — forpas, Dec 10 '18 at 16:16
See [this other answer](https://stackoverflow.com/a/1075699/6383857) — StaticBeagle, Dec 10 '18 at 16:16
Foo has an equals method defined and it checks if 2 list fields are equal. I tried updating it to check for containsAll instead but that din't help. — Random, Dec 10 '18 at 21:18
for groovy, use @EqualsAndHashCode. for java override equals/hashcode — Gaurav, Feb 16 '22 at 22:27

score 8 · Answer 1 · answered Aug 06 '21 at 08:06

8

you can do this with assertJ:

assertThat(fooA).usingRecursiveComparison().ignoringCollectionOrder().isEqualTo(fooB)

answered Aug 06 '21 at 08:06

alampada

1

Recursive comparison allows you to compare field by field recursively even if they were not of the same type. – IamDOM Jun 10 '22 at 12:04

score 4 · Answer 2 · answered Dec 10 '18 at 16:23

What you are looking for is containsExactlyInAnyOrderElementsOf(Iterable) defined in IterableAssert (emphasis is mine) :

Verifies that the actual group contains exactly the given values and nothing else, in any order.

You could write so :

List<Foo> fooA;
List<Foo> fooB;
//...
assertThat(fooA).containsExactlyInAnyOrderElementsOf(fooB);

2 Answers2