Grails Model Unity Test - grails

Question

I have a "domain"(model) that want to do an Unity Test to check if works.
But when I execute the test I get
java.lang.IllegalArgumentException: Test class can only have one constructor
Thats always happen when trying to initialize a class of some domain(model).
What would be the approach to do correctly the testcase?
class Race {
static constraints = { }
String name
Date startDate
String city
String state
BigDecimal distance
BigDecimal cost
Integer maxRunners = 100000
BigDecimal inMiles() {
return 0.6
}
}
And in the Unity Test Class
import grails.test.mixin.TestFor
import spock.lang.Specification
#TestFor(Race)
class RaceTest extends Specification {
void testInMiles() {
when:
def model = new Race(distance:5.0);
then:
0.6 == model.inMiles()
}
}

Answer 1

In Grails 2.4.x (which is what I'm assuming you're using) the default test type is a Spock test, and that's what's created by the generate-* scripts. You can still write your own tests in JUnit 3 or 4 style if you prefer. But test classes in Spock (at least using the Grails integration, I'm not sure if it's as strict outside of Grails) have to have names ending in "Spec". That's why you're seeing that error.
Test methods do not have to be void and start with "test" (JUnit 3 style) or be void and have an #Test annotation (JUnit 4 style). The test runner decides if a method is a test method if it's public (either explicitly or if there's no scope modifier) and there's at least one labelled block, e.g. when:, given:, then:, etc. Further, Spock uses some AST magic to allow you to use spaces in method names (you just have to quote the whole name) and have expressive, self-descriptive method names, e.g.
def 'an admin without ROLE_SUPER cannot view records of other admins'() {
...
}