Issue
I have a sample Spring Boot app with the following
Boot main class
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
Controller
@RestController
@EnableAutoConfiguration
public class HelloWorld {
@RequestMapping("/")
String gethelloWorld() {
return "Hello World!";
}
}
What's the easiest way to write a unit test for the controller? I tried the following but it complains about failing to autowire WebApplicationContext
@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = DemoApplication.class)
public class DemoApplicationTests {
final String BASE_URL = "http://localhost:8080/";
@Autowired
private WebApplicationContext wac;
private MockMvc mockMvc;
@Before
public void setup() {
this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
}
@Test
public void testSayHelloWorld() throws Exception{
this.mockMvc.perform(get("/")
.accept(MediaType.parseMediaType("application/json;charset=UTF-8")))
.andExpect(status().isOk())
.andExpect(content().contentType("application/json"));
}
@Test
public void contextLoads() {
}
}
Solution
Spring MVC offers a standaloneSetup that supports testing relatively simple controllers, without the need of context.
Build a MockMvc by registering one or more @Controller's instances and configuring Spring MVC infrastructure programmatically. This allows full control over the instantiation and initialization of controllers, and their dependencies, similar to plain unit tests while also making it possible to test one controller at a time.
An example test for your controller can be something as simple as
public class DemoApplicationTests {
private MockMvc mockMvc;
@Before
public void setup() {
this.mockMvc = MockMvcBuilders.standaloneSetup(new HelloWorld()).build();
}
@Test
public void testSayHelloWorld() throws Exception {
this.mockMvc.perform(get("/")
.accept(MediaType.parseMediaType("application/json;charset=UTF-8")))
.andExpect(status().isOk())
.andExpect(content().contentType("application/json"));
}
}
Answered By - Master Slave
