How to autowire MockMvc bean correctly - spring-mvc

Question

I have a bit of trouble with this.
I'm trying to test the web layer of my Spring boot app (with JUnit5).
I'm using the #WebMvcTest(NoteController::class) to allow me to autowire MockMvc in order to mock requests.
But I get the below error :
kotlin.UninitializedPropertyAccessException: lateinit property mvc has not been initialized
NoteControllerTest
import org.hamcrest.Matchers.`is`
import org.junit.Test
import org.junit.jupiter.api.extension.ExtendWith
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest
import org.springframework.http.MediaType
import org.springframework.test.context.junit.jupiter.SpringExtension
import org.springframework.test.web.servlet.MockMvc
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post
import org.springframework.test.web.servlet.result.MockMvcResultMatchers.*
#ExtendWith(SpringExtension::class)
#WebMvcTest(NoteController::class)
class NoteControllerTest {
#Autowired
private lateinit var mvc: MockMvc
#Test
fun should_create_a_note() {
mvc.perform(
post("/notes"))
.andExpect(status().isCreated)
.andExpect(content().contentType(MediaType.APPLICATION_JSON_UTF8))
.andExpect(jsonPath("$.content", `is`("my content")))
}
}
NoteController
import fr.$$.$$.api.CreateNote
import fr.$$.$$.api.FetchNote
import fr.$$.$$.resources.Note
import fr.$$.$$.resources.toResource
import org.springframework.http.HttpStatus
import org.springframework.http.ResponseEntity
import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.PostMapping
import org.springframework.web.bind.annotation.RestController
import java.net.URI
#RestController("/notes")
class NoteController(val createNote: CreateNote,
val fetchNote: FetchNote) {
#GetMapping
fun getAllNotes(): ResponseEntity<List<Note>> {
return ResponseEntity(fetchNote.all().toResource(), HttpStatus.OK)
}
#PostMapping
fun createNote(): ResponseEntity<Note> {
val note = createNote.with("my content").toResource()
return ResponseEntity.created(URI("")).body(note)
}
}
SmartNotesApplicationTest
import org.junit.Test
import org.junit.jupiter.api.extension.ExtendWith
import org.springframework.boot.test.context.SpringBootTest
import org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT
import org.springframework.test.context.junit.jupiter.SpringExtension
#ExtendWith(SpringExtension::class)
#SpringBootTest(webEnvironment = RANDOM_PORT)
class SmartNotesApplicationTest {
#Test
fun contextLoad() {
}
}
Thanks in advance.

Answer 1

I inject the WebApplicationContext and then build a new MockMvc for each test from that.
#SpringBootTest
class SomeTest {
#Autowired
lateinit var webApplicationContext: WebApplicationContext
lateinit var mockMvc: MockMvc
#BeforeEach
fun beforeEach() {
mockMvc = MockMvcBuilders.webAppContextSetup(webApplicationContext).build()
}
// Tests go here!
}

Answer 2

thanks for the answers, I put the working answer in Java with Spring Boot 2.2.6:
AuthorController.class
import org.springframework.web.bind.annotation.*;
#RestController
#RequestMapping(path = "/authors")
public class AuthorController {
#GetMapping("/health")
public boolean healthcheck() {
return true;
}
}
AuthorControllerIT.class
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.result.MockMvcResultHandlers;
import org.springframework.test.web.servlet.result.MockMvcResultMatchers;
#SpringBootTest
#AutoConfigureMockMvc
class AuthorControllerIT {
#Autowired
private MockMvc mockMvc;
#Test
public void test_web_layer() throws Exception {
mockMvc.perform(MockMvcRequestBuilders.get("/authors/health"))
.andDo(MockMvcResultHandlers.print())
.andExpect(MockMvcResultMatchers.status().isOk())
.andExpect(MockMvcResultMatchers.content().string("true"));
}
}
Note :
You can use #WebMvcTest(AuthorController.class) instead of #SpringBootTest + AutoConfigureMockMvc
With this annotation, it will only load the web layer.
If you have dependencies in your controller (services, repositories...) you must use :
#MockBean
private MyService service;