Grails 2.4 Command objects nullable constraint and dependency injection - grails

Question

we are preparing for Grails 2.4 upgrade. One of the issues we face is that
most of the command object unit tests fails because of injected properties, like
services, are required to be not null during validation.
Is there any suggested way how to test this? Should we mock all properties although some are not needed for test? or is there a way to do this differently?
After my question is answered by Jeff, I share links with more information about new functionalities:
doWithSpring and doWithConfig are shortly described in What's new in 2.4: http://grails.org/doc/latest/guide/introduction.html#whatsNew24 in Unit Testing improvements section
There is also a JIRA issue with example: https://jira.grails.org/browse/GRAILS-11003

Answer 1

Most unit tests don't want or need the application context all spun up and populated. Unit tests can add whatever they want (or nothing) to the application context. In recent versions of Grails you can do something like this...
A controller and command object:
// grails-app/controllers/demo/DemoController.groovy
package demo
class DemoController {
def processName(SomeCommand co) {
render co.someValue
}
}
class SomeCommand {
String name
def helperService
def getSomeValue() {
helperService.processValue(name)
}
}
A service:
// grails-app/services/demo/HelperService
package demo
class HelperService {
def processValue(String originalValue) {
"__${originalValue}__"
}
}
A unit test:
// grails-app/test/unit/demo/DemoControllerSpec.groovy
package demo
import grails.test.mixin.TestFor
import spock.lang.Specification
#TestFor(DemoController)
class DemoControllerSpec extends Specification {
def doWithSpring = {
helperService HelperService
}
void 'process name'() {
when:
params.name = 'Jeff'
controller.processName()
then:
response.contentAsString == '__Jeff__'
}
}
That test will pass with Grails 2.4.2.
I hope that helps.