Spring MVC unit (minimal integration) test that uses Spring config for the controller setup

AbstractHandlerMethodMappingTestOverride.java

package org.springframework.web.servlet.handler

import org.springframework.web.context.WebApplicationContext

/**
 * Workaround to register a controller with the WebAppContext because detectHandlerMethods is protected
 *
 * This allows our Mvc Unit tests to use the wired up Spring Jackson converters and mappers,
 * without having to specify them individually in every test
 *
 * Your test will need this annotation too:
 * @DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
 */
class AbstractHandlerMethodMappingTestOverride {
    static WebApplicationContext addController(WebApplicationContext wac, Object controller) {
        wac.getBean('requestMappingHandlerMapping').detectHandlerMethods(controller)
        return wac
    }
}

AddressControllerSpec.groovy

//@UnitTestDI is a helper groovy @AnnotationCollector that includes:
//  @WebAppConfiguration
//  @ContextConfiguration for WebMvcConfig, Validators, and Properties
//  @DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
@UnitTestDI
class AddressControllerSpec extends Specification {

    @Autowired
    WebApplicationContext wac

    AddressService addressService = Mock()

    MockMvc mockMvc
    AddressController controller = new AddressController()

    def setup() {
        controller.addressService = addressService
        mockMvc = MockMvcBuilders.webAppContextSetup(addController(wac, controller)).build()
    }

    def "should test buildAddress"() {
        given:
        DateTime beginDate = createDateTime('10/12/2014')
        AddressView view = new AddressView(number: 321)

        when:
        def response = mockMvc.perform(get('/api/address').param('beginDate', '10/12/2014')).andReturn()
        def content = new JsonSlurper().parseText(response.contentAsString)

        then:
        1 * addressService.fetchAddress(beginDate) >> view

        response.status == OK.value()
        content.number == 321
    }