Unit testing validators

[jpwinans]

Hey all,

I was wondering if anyone had any solutions for unit testing validators withing the Spring Framework architecture?

Thanks,
James Winans II

[Alef Arendsen]

The validators are not tied to any specific protocol, so you should be able to instantiate them without any problems.

Are there any issues you're running into?

[jpwinans]

Hey,

The main problem I'm having is dealing with the Errors object in the context of JUnit.
In setUp() I instantiate three domain objects. One I set with good values. One I set with blank values. And another I fill with bad values. I then pass each of them through my validation object, passing also three BindExceptions I instantiated (errorsGood, errorsBad, & errorsBlank).

    private ComputerValidator computerValidator;
    private Computer computerGood, computerBlank, computerBad;
    private BindException errorsGood, errorsBad, errorsBlank;
    
    public void setUp(){
        ComputerValidator computerValidator = new ComputerValidator();
        Computer computerGood = new Computer();
        Computer computerBad = new Computer();
        Computer computerBlank = new Computer();
        BindException errorsGood = new BindException(computerGood, "computerGood");
        BindException errorsBad = new BindException(computerBad, "computerBad");
        BindException errorsBlank = new BindException(computerBlank, "computerBlank");
        computerGood.setRow(29);
        computerGood.setIp("156.152.1.123");
        computerGood.setSeat(3);
        computerGood.setHostname("LOGOS");
        computerGood.setOs("Windows XP");
        computerBad.setRow(42);
        computerBad.setIp("www.cpog.com");
        computerBad.setSeat(11);
        computerValidator.validate(computerGood, errorsGood);
        computerValidator.validate(computerBad, errorsBad);
        computerValidator.validate(computerBlank, errorsBlank);
    }

Then in my test code I have the following:

public void testValidateInfo(){
        boolean hasErrorsGood = errorsGood.hasErrors();
        boolean hasErrorsBad = errorsBad.hasErrors();
        boolean hasErrorsBlank = errorsBlank.hasErrors();
        assertEquals(true, hasErrorsBlank);
        assertEquals(false, hasErrorsGood);
        assertEquals(false, hasErrorsBad);
    }

This obviously doesn't work because I get a NullPointerException on "errorsGood.hasErrors();"
Any help would be great.

Thanks,
James Winans

[Colin Sampaleanu]

I'm confused as to how you could be getting a NullPointerException on

errorsGood.hasErrors();

since that method should always run ok:

public boolean hasErrors() {
return !this.errors.isEmpty();
}

The errors var is set in the constructor, and nothing else could be causing a NPE...

[katentim]

You should get a NPE because you've defined local variables in setup. The member variables you are trying to use in testValidateInfo aren't instantiated.

[jpwinans]

You should get a NPE because you've defined local variables in setup. The member variables you are trying to use in testValidateInfo aren't instantiated.

I guess I need to spend a bit more time with the Java basics. I thought that since I'd declared their reference as an instance variable, outside of setUp(), populating them from within setUp() would have had Class scope as well. :?

[Colin Sampaleanu]

You've declared the them twice, once as a field, and once as a local var. Just assign to the fields in setup, don't create a variable declaration there too...

[jpwinans]

Ah geesh. I see what I did. :oops: Thanks for the help.

[David Santoro]

Sorry for resurrecting this thread.
I am interested in the test showed in this thread. I wonder if it is a good unit test for validators (apart of the scope error).
Is it enough testing the presence of errors or should I test the errors one by one?