How to AssertEquals 2 object arrays (both with an array field)

Question

I am trying to assert that 2 arrays of a UserDto object are equal to one another in a unit test that I am implementing. See below my UserDto class and the 2 UserDto instances I am trying to compare

UserDto class:

public record UserDto(
    @NotBlank Long id,
    @NotBlank String name,
    @NotBlank String lastname,
    @NotBlank String email,
    @NotBlank String[] roles) {
}

Instances of UserDto

 UserDto basicUserDto = new UserDto(
            2L,
            "donquixote",
            "doflamingo",
            "doffy@acme.com",
            new String[]{"ROLE_USER"}
        );


UserDto accountantUserDto = new UserDto(
            3L,
            "monkey",
            "d-luffy",
            "luffy@acme.com",
            new String[]{"ROLE_ACCOUNTANT"}
        );

Below I have my expected and actual objects, and my assertArrayEquals() call:

    UserDto[] expectedDtoArray = new UserDto[]{basicUserDto, accountantUserDto};
    UserDto[] actualDtoArray = userHelper.buildUserDtoArray(List.of(basicUser, accountantUser));
    assertArrayEquals(expectedDtoArray, actualDtoArray);

when I run this test, I get the following response:

array contents differ at index [0], expected: <UserDto[id=2, name=donquixote, lastname=doflamingo, email=doffy@acme.com, roles=[Ljava.lang.String;@79d06bbd]> but was: <UserDto[id=2, name=donquixote, lastname=doflamingo, email=doffy@acme.com, roles=[Ljava.lang.String;@2caa5d7c]>

Expected :UserDto[id=2, name=donquixote, lastname=doflamingo, email=doffy@acme.com, roles=[Ljava.lang.String;@79d06bbd]

Actual   :UserDto[id=2, name=donquixote, lastname=doflamingo, email=doffy@acme.com, roles=[Ljava.lang.String;@2caa5d7c]

Is there a way to assert that 2 array of objects with an array field are equal without having to manually implement separate method that will compare the 2 array fields?

I tried converting both arrays to a String object using the toString() method, which did not work. I also tried using ObjectMapper.writeValueAsString() method which also did not work.

Answer 1

I did not implement the equals method in my UserDto class.

See below equals method implementation. Since the id field is a unique field, if the UserDto objects have the same id field, both objects will be considered equal.

equals() implementation below:

@Override
    public boolean equals(Object o) {
        UserDto dto = (UserDto)o;
        if (this.id.equals(dto.id)){
            return true;
        }
        return false;
    }