Grails: Testing constraint error messages using spock - unit-testing

Question

I am currently having issues validating my constraint messages in spock using grails 2.4.2. When testing i keep getting the default error message rather than my custom message. However when i print to a view using grails error tag i get the correct error message. I have even deleted the default from message.propperties.
Here is what my spec looks like:
import com.fishLogger.user.User
import com.fishLogger.DomainErrorHandling
import grails.test.mixin.TestFor
import org.springframework.context.MessageSource
import spock.lang.Specification
/**
* See the API for {#link grails.test.mixin.domain.DomainClassUnitTestMixin} for usage instructions
*/
#TestFor(User)
class UserSpec extends Specification {
MessageSource messageSource
def setup() {
DomainErrorHandling.enable(new User())
}
def cleanup() {
}
void "test Invalid User Name Errors"(){
when:
User user = new User(userName:userName, password:password, email:email)
//user.errors.allErrors.get(0).code
user.validate()
then:
user.errorMessage()==expectedMessage
where:
userName | password | email | expectedMessage
"" |"vailidPassword" | "thisworks#email.com" | "User name must be entered"
//"asd" |"vailidPassword" | "thisworks#email.com" | "User name must be atleast 6 chacters long"
//" " |"vailidPassword" | "thisworks#email.com" | "User name must be entered"
//"aaaaaaaaaaaaaaaaaaaaa" |"vailidPassword" | "thisworks#email.com" | "User name can not be greater than 20 characters"
}
Where enable is a call loading a helping method to the domain to grab the error message
class DomainErrorHandling {
public static void enable(Object obj){
obj.class.metaClass.errorMessage = {
MessageSource messageSource = Holders.applicationContext.getBean("messageSource")
def errorString = delegate?.errors?.allErrors?.collect{error ->
messageSource.getMessage(error,Locale.default)
}?.join(' \n')
return errorString
}
}
}
Any help or guidance would be great. I know that testing the error messages should be more of a UI test but i would really prefer to test them with my unit tests as well.

Answer 1

As for why it still shows the old message when you delete it from message.properties, check out the getDefaultMessage() in MessageSourceResolvable. I'm guessing that your custom message isn't visible to the test, either because its key is misspelled or some Grails test bootstrap problem.
I would try printing out the getCodes() of the error in your errorMessage() method, and see if any of the codes listed is the key to one of your custom ones in message.properties.

Answer 2

Assuming a Book domain class with a non nullable name property you can do the following:
#Mock(Book)
class BookSpec extends Specification {
StaticMessageSource messageSource
def setup () {
messageSource = (StaticMessageSource)grailsApplication.mainContext.getBean('messageSource')
}
def "check name validation error message" () {
given:
messageSource.addMessage ("nullable.name", Locale.default, "Null!")
Book book = new Book (name:null)
when:
book.validate ()
then:
messageSource.getMessage (book.errors.getFieldError ('name'), Locale.default) == "Null!"
}
}