How does `containsInAnyOrder` compare items?

Question

I've got a CustomField class and I've overriden the equals and hashcode methods. But when I try to compare 2 lists of CustomField objects, it fails. Why wouldn't the containsInAnyOrder work in the following:

Overrides:
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        CustomField that = (CustomField) o;
        return Objects.equals(this.id, that.id) &&
                Objects.equals(this.name, that.name);
    }

    @Override
    public int hashCode() {
        return Objects.hash(this.id, this.name);
    }

        List<CustomField> actual = ImmutableList.of(
                new CustomField(1L, "1L"),
                new CustomField(2L, "2L"),
                new CustomField(3L, "3L")
        );
        List<CustomField> expected = ImmutableList.of(
                new CustomField(1L, "1L"),
                new CustomField(2L, "2L"),
                new CustomField(3L, "3L")
        );
        assertThat(actual, containsInAnyOrder(expected)); /// why does this fail?

Answer 1

Check this out: https://hamcrest.org/JavaHamcrest/javadoc/1.3/org/hamcrest/Matchers.html#containsInAnyOrder(T...)

containsInAnyOrder expects an array of elements to match with the provided actual list. You are passing expected as list. And actual is not a List of List. So, it will try to search for an entire list as an element in actual.

Probably you will need to use containsInAnyOrder(expected.toArray()).

I.e.

assertThat(actual, containsInAnyOrder(expected.toArray()));

Try it out.