How to test spring 5 controllers with Junit5 - spring-mvc

Question

I'm trying to test my Spring 5 web controllers with JUnit 5.
The two way to test controller (as mentionned in spring documentation) always give me null pointer.
This is my test class
import com.lacunasaurus.gamesexplorer.test.configuration.TestBackEndConfiguration;
import com.lacunasaurus.gamesexplorer.test.configuration.TestWebConfig;
import org.junit.Before;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.junit.platform.runner.JUnitPlatform;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import org.springframework.test.context.web.WebAppConfiguration;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
#RunWith(JUnitPlatform.class)
#ExtendWith(SpringExtension.class)
#WebAppConfiguration()
#ContextConfiguration(classes = {TestWebConfig.class, TestBackEndConfiguration.class})
public class TestAuthenticationCreateAccountController {
#Autowired
private WebApplicationContext wac;
private MockMvc mockMvc;
#Before
public void setup() {
// this.mockMvc = MockMvcBuilders.standaloneSetup(new AuthenticationCreateAccountController()).build();
this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
}
#Test
public void getAccount() throws Exception {
// Here i've got an null pointer
mockMvc.perform(get("/"));
}
}
Here my web configuration for tests
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ResourceBundleMessageSource;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
#Configuration
#ComponentScan(basePackages = {"com.lacunasaurus.gamesexplorer.web"})
public class TestWebConfig implements WebMvcConfigurer, ApplicationContextAware {
private ApplicationContext applicationContext;
#Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
}
And now my controller
#Controller
#RequestMapping("/create-account")
public class AuthenticationCreateAccountController {
#Autowired
UserAccountValidator accountValidator;
#Autowired
AuthenticationService authenticationService;
#GetMapping
public String navigate() {
return "authentication/create-account";
}
#ModelAttribute("userAccount")
public UserAccount setDefaultAccount() {
return new UserAccount();
}
#InitBinder
protected void initBinder(WebDataBinder binder) {
binder.addValidators(accountValidator);
}
#PostMapping
public String createAccount(#Validated UserAccount userAccount, BindingResult bindingResult) {
if (bindingResult.hasErrors()) {
return "authentication/create-account";
}
authenticationService.createUserAccount(userAccount);
return "authentication/create-account";
}
}
EDIT : The stacktrace given by the IDE
java.lang.NullPointerException at com.lacunasaurus.gamesexplorer.test.controller.TestAuthenticationCreateAccountController.getAccount(TestAuthenticationCreateAccountController.java:41)
Results :
Tests in error:
TestAuthenticationCreateAccountController.getAccount:41 NullPointer
I've got already test my backend with junit 5 and spring and everything work well.
Thanks to thoses who will help me to understand how to test controller :)

Answer 1

The new test for controllers :
#ExtendWith(SpringExtension.class)
#WebAppConfiguration()
#ContextConfiguration(classes = {TestWebConfig.class, TestBackEndConfiguration.class})
#TestInstance(Lifecycle.PER_CLASS)
public class TestAuthenticationCreateAccountController {
#Autowired
private WebApplicationContext wac;
private MockMvc mockMvc;
#BeforeEach
void setup() {
this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
}
#Test
void getAccount() throws Exception {
mockMvc.perform(get("/toto")).andExpect(status().isOk());
}
}

Answer 2

If you're using Junit5, See this reference
#ExtendWith(MockitoExtension.class) // For Junit5
public class TestAuthenticationCreateAccountController {
#Mock
private WebApplicationContext wac;
#InjectMocks
private AuthenticationCreateAccountController ac;
private MockMvc mockMvc;
#BeforeEach // For Junit5
public void setup() {
mockMvc = MockMvcBuilders.standaloneSetup(ac).build();
}
#Test
public void getAccount() throws Exception {
mockMvc.perform(get("/"));
}
}

Answer 3

In order to use JUnit Jupiter, you must use autoconfigure MockMvc. This is a help to resolve all related configuration.
#ExtendWith(SpringExtension.class)
#WebAppConfiguration()
#AutoConfigureMockMvc

Answer 4

#Autowired
private MockMvc mockMvc;
This should fix your issue.