REST API integration – an example

Spring MVC provides an integration testing utility named MockMvc. We can use this to write an integration test for REST API controller classes. Let's see how this works for the /account/<accountId> endpoint of the AccountController class:

package com.dineshonjava.bookshop.accountservice;
import static org.mockito.BDDMockito.given;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import com.dineshonjava.bookshop.accountservice.controller.AccountController;
import com.dineshonjava.bookshop.accountservice.domain.Account;
import com.dineshonjava.bookshop.accountservice.repository.AccountRepository;

@RunWith(SpringRunner.class)
@WebMvcTest(controllers = AccountController.class)
public class AccountControllerIntegrationTest {
            @Autowired
            private MockMvc mockMvc;
            @MockBean
            private AccountRepository accountRepository;
            @Test
            public void shouldReturnFullName() throws Exception {
                        Account rushika = new Account(1003, "Rushika Rajput", "Noida", "9832XXX23", "rushika.raj@mail.com");
                        given(accountRepository.findAccountByAccountId(10003)).willReturn(rushika);
                        mockMvc.perform(get("/account/10003"))
                        .andExpect(content().string("Hello Rushika Rajput!"))
                        .andExpect(status().is2xxSuccessful());
            }
}

In the preceding integration test class, we defined a test method for the findAccountById() method of the AccountController class by using the MockMvc framework. In the preceding class, we used the @WebMvcTest annotation to tell Spring which controller we're testing. We also used the @MockBean annotation to mock the AccountRepository class in our Spring context.