Let us implement test cases for each RESTful service of a microservice by performing the following steps:

1. Just like in the previous recipe, add the needed Spring Test starter POM dependency in the project's pom.xml file.

2. Inside src/test/java, create an org.packt.microservice.core.test package and drop a test class that executes blocking RESTful services using org.springframework.boot.test.web.client.TestRestTemplate:

import static org.assertj.core.api.Assertions.assertThat; 
@RunWith(SpringRunner.class) 
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT) 
@ContextConfiguration(classes={ HRDeptBootApplication.class,  
   CacheConfig.class, SpringDataConfig.class,  
   SpringAsynchConfig.class }) 
public class TestRestService { 
    
   @Autowired 
   private TestRestTemplate restTemplate; 
 
   @Test 
   public void exampleTest() { 
      String body = this.restTemplate.getForObject( 
"/objectSampleRest", String.class); 
      assertThat(body).isEqualTo("Hello World"); 
   } 
    
   @Test 
   public void exampleTestList() { 
      String body = this.restTemplate.getForObject( 
"/objectSampleRest", String.class); 
      assertThat(body).isEqualTo("Hello World"); 
   } 
    
   @Test 
   public void exampleTestListAll() { 
      List<Department> body =  
         this.restTemplate.getForObject( 
"/listDept", List.class); 
      assertNotNull(body); 
System.out.println(body); 
   } 
}

3. Add another test class that scrutinizes asynchronous services that return the Callable<T>, DeferredResult<T>, and WebAsyncTask<T> tasks:

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.asyncDispatch; 
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get; 
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.header; 
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.request; 
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status; 
@RunWith(SpringRunner.class) 
@AutoConfigureMockMvc 
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT) 
@ContextConfiguration(classes={ HRDeptBootApplication.class,  
   CacheConfig.class, SpringDataConfig.class,  
   SpringAsynchConfig.class }) 
public class TestAsyncService { 
    
   @Autowired 
    private MockMvc mockMvc; 
         
    @Test 
    public void testController () throws Exception { 
        MvcResult result = mockMvc.perform( 
get("/callSelectDept/359.json")) 
       .andExpect(request().asyncStarted()) 
       .andReturn();  
        result.getRequest().getAsyncContext() 
.setTimeout(5000); 
        result.getAsyncResult();  
        result= mockMvc.perform(asyncDispatch(result)) 
           .andExpect(status().isOk()) 
           .andExpect(header().string("Content-Type",  
MediaType.APPLICATION_JSON_UTF8_VALUE)) 
           .andReturn();  
        System.out.println(result.getResponse() 
.getContentAsString());  
    } 
}

4. Lastly, add a Spring TestContext class that evaluates reactive RESTful services exposed through either the @RestController or HandlerRouter<T> implementation. This test class uses the new API org.springframework.test.web.reactive.server.WebTestClient from Spring 5:

import static org.junit.Assert.assertEquals; 
@RunWith(SpringRunner.class) 
@AutoConfigureMockMvc 
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT) 
@ContextConfiguration(classes={ HRDeptBootApplication.class,  
   HttpServerConfig.class, SpringDataConfig.class,  
   SpringAsynchConfig.class }) 
public class TestReactService { 
 
   @Autowired 
   private WebTestClient webTestClient; 
    
    @Test 
    public void testDeptById(){ 
         FluxExchangeResult<Department> result =  
            webTestClient.get() 
.uri("http://localhost:8090/ch10- 
               dept/selectReactDept/359") 
.accept(MediaType.APPLICATION_JSON_UTF8) 
            .exchange().returnResult(Department.class); 
            assertEquals( result.getStatus().value(), 200); 
            Department dept =  
               result.getResponseBody().blockFirst(); 
            System.out.println(dept.getName()); 
       } 
     
    @Test 
    public void testDeptByIdRouter(){ 
         FluxExchangeResult<Department> result =  
            webTestClient.get() 
.uri("http://localhost:8901/selectDeptById/359") 
.accept(MediaType.APPLICATION_JSON_UTF8) 
         .exchange().returnResult(Department.class); 
         assertEquals( result.getStatus().value(), 200); 
Department dept =  
   result.getResponseBody().blockFirst(); 
         System.out.println(dept.getName()); 
       } 
}