Spring Boot & H2 - Unit Test Controller

As in previous chapter we've completed our REST APIs. Now let's create the following structure in src/main/test folder.

• com.tutorialspoint.controller.EmployeeControllerTest − A Unit Tester Class to unit test all methods of EmployeeController.

• com.tutorialspoint.repository.EmployeeRepositoryTest − A Unit Tester Class to unit test all methods of EmployeeRepository.

• com.tutorialspoint.service.EmployeeServiceTest − A Unit Tester Class to unit test all methods of EmployeeService.

SprintBootH2ApplicationTests class is already present. We need to create the above packages and relevant classes.

EmployeeControllerTest

To test a REST Controller, we need the following annotation and classes −

• @ExtendWith(SpringExtension.class) − Mark the class to run as test case using SpringExtension class.

• @SpringBootTest(classes = SprintBootH2Application.class) − Configure the Spring Boot application.

• @AutoConfigureMockMvc − To automatically configure the MockMVC to mock HTTP Requests and Response.

• @Autowired private MockMvc mvc; − MockMvc object to be used in testing.

• @MockBean private EmployeeController employeeController − EmployeeController mock object to be tested.

Following is the complete code of EmployeeControllerTest.

package com.tutorialspoint.controller;
import static org.hamcrest.core.Is.is;
import static org.mockito.BDDMockito.given;
import static org.mockito.Mockito.doNothing;
import static org.springframework.http.MediaType.APPLICATION_JSON;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import java.util.ArrayList;
import java.util.List;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
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.boot.test.mock.mockito.MockBean;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import org.springframework.test.web.servlet.MockMvc;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.tutorialspoint.entity.Employee;
import com.tutorialspoint.sprintbooth2.SprintBootH2Application;
@ExtendWith(SpringExtension.class)
@SpringBootTest(classes = SprintBootH2Application.class)
@AutoConfigureMockMvc
public class EmployeeControllerTest {
   @Autowired
   private MockMvc mvc;
   @MockBean
   private EmployeeController employeeController;
   @Test
   public void testGetAllEmployees() throws Exception {
      Employee employee = getEmployee();
      List<Employee> employees = new ArrayList<>();
      employees.add(employee);
      given(employeeController.getAllEmployees()).willReturn(employees);
      mvc.perform(get("/emp/employees/").contentType(APPLICATION_JSON)).andExpect(status().isOk())
         .andExpect(jsonPath("$[0].name", is(employee.getName())));
   }
   @Test
   public void testGetEmployee() throws Exception {
      Employee employee = getEmployee();
      given(employeeController.getEmployee(1)).willReturn(employee);
      mvc.perform(get("/emp/employee/" + employee.getId()).contentType(APPLICATION_JSON)).andExpect(status().isOk())
         .andExpect(jsonPath("name", is(employee.getName())));
   }
   @Test
   public void testDeleteEmployee() throws Exception {
      Employee employee = getEmployee();
      doNothing().when(employeeController).deleteEmployee(1);
      mvc.perform(delete("/emp/employee/" + employee.getId()).contentType(APPLICATION_JSON))
         .andExpect(status().isOk()).andReturn();
   }
   @Test
   public void testAddEmployee() throws Exception {
      Employee employee = getEmployee();
      doNothing().when(employeeController).addEmployee(employee);
      mvc.perform(post("/emp/employee/").content(asJson(employee)).contentType(APPLICATION_JSON))
         .andExpect(status().isOk()).andReturn();
   }
   @Test
   public void testUpdateEmployee() throws Exception {
      Employee employee = getEmployee();
      doNothing().when(employeeController).updateEmployee(employee);
      mvc.perform(put("/emp/employee/").content(asJson(employee)).contentType(APPLICATION_JSON))
         .andExpect(status().isOk()).andReturn();
   }
   private Employee getEmployee() {
      Employee employee = new Employee();
      employee.setId(1);
      employee.setName("Mahesh");
      employee.setAge(30);
      employee.setEmail("mahesh@test.com");
      return employee;
   }
   private static String asJson(final Object obj) {
      try {
         return new ObjectMapper().writeValueAsString(obj);
      } catch (Exception e) {
         throw new RuntimeException(e);
      }
   }
}

Run the test cases.

Right Click on the file in eclipse and select Run a JUnit Test and verify the result.