Filters with dependencies mocking with Spock

MySimpleFiltersSpec

package grails_filter_tests

import spock.lang.Specification
import org.springframework.beans.factory.config.MethodInvokingFactoryBean
import grails.test.mixin.*
import grails.test.mixin.support.GrailsUnitTestMixin
import grails.test.mixin.web.FiltersUnitTestMixin
@TestFor(SimpleController)
@TestMixin([GrailsUnitTestMixin,FiltersUnitTestMixin])
@Mock(MySimpleFilters)
class MySimpleFiltersSpec extends Specification {
	

	def 'show working mock test for filter'() {
			
		given:
			defineBeans {
	            simpleService(MethodInvokingFactoryBean) {
	                targetObject = this
	                targetMethod = "mockSimpleService"
					arguments = ['hi']
	            }
	        }
			
		when:
			withFilters(action:"index") {
				controller.index()				
			}
			
		then:
			request.text == 'hi'
			response.text == 'hi'
	}
	
	SimpleService mockSimpleService(String text) {
		SimpleService service = Mock(SimpleService)
		
		service.aMethod() >> text
		0 * service._
		
		return service
	}
}