19.How to Perform Integration Testing for Spring Boot Controller Classes with MockMvc

Create a folder for the controller test class at the path: test > controller
Create a TestController class inside this folder.

Implement a setup() function annotated with @BeforeEach. This function initializes new objects to be used in the save, edit, and delete functions.

Implement the showAllData() function.

Run the showAllData() function and verify its behavior through testing.

Implement all other required test functions following a similar pattern.

Run the TestController class to execute all tests.

The test results will be displayed, showing the outcome of each function test.

You can find the related GitHub repository branch here: book-details-integration-test-controller-class

BookControllerTest.java

package com.codersstash.book_details.controller;


import com.codersstash.book_details.entity.Book;
import com.codersstash.book_details.service.BookService;
import org.junit.jupiter.api.BeforeEach;
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.WebMvcTest;
import org.springframework.test.context.bean.override.mockito.MockitoBean;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;

import java.util.Arrays;
import java.util.List;

import static org.mockito.Mockito.*;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

@ExtendWith(SpringExtension.class)
@WebMvcTest(BookController.class)
public class BookControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @MockitoBean
    private BookService bookService;

    private Book book;
    @BeforeEach
    void setUp(){
        book = new Book();
        book.setBook_id(1);
        book.setBook_name("Test Book");
        book.setBook_author("Test Author");
        book.setBook_publisher("Test Publisher");
        book.setBook_description("Test Description");
        book.setBook_price(28.59);
    }

    @Test
    void showAllBooks_shouldReturnIndexPage() throws Exception {
        List<Book> books= Arrays.asList(book);
        when(bookService.getAllBooks()).thenReturn(books);

        mockMvc.perform(MockMvcRequestBuilders.get("/index"))
                .andExpect(status().isOk())
                .andExpect(view().name("index"))
                .andExpect(model().attributeExists("books"));

        verify(bookService,times(1)).getAllBooks();
    }

    @Test
    void getNewBookForm_ShouldReturnAddNewBookFormPage() throws Exception {
        mockMvc.perform(MockMvcRequestBuilders.get("/addnewbook"))
                .andExpect(status().isOk())
                .andExpect(view().name("addNewBookForm"))
                .andExpect(model().attributeExists("book"));
    }

    @Test
    void addNewBook_ShouldRedirectToIndex()throws Exception{
        when(bookService.saveBook(any(Book.class))).thenReturn(book);
        mockMvc.perform(MockMvcRequestBuilders.post("/saveBook")
                .flashAttr("book",book))
                .andExpect(status().is3xxRedirection())
                .andExpect(redirectedUrl("/index"));

        verify(bookService,times(1)).saveBook(any(Book.class));
    }

    @Test
    void editBook_shouldReturnUpdateForm()throws Exception{
        when(bookService.getBookById(1)).thenReturn(book);

        mockMvc.perform(MockMvcRequestBuilders.get("/editbook/1"))
                .andExpect(status().isOk())
                .andExpect(view().name("updateBookForm"))
                .andExpect(model().attributeExists("book"));

        verify(bookService,times(1)).getBookById(1);
    }

    @Test
    void deleteBook_ShouldRedirectToIndex()throws Exception{
        doNothing().when(bookService).deleteBook(1);
        mockMvc.perform(MockMvcRequestBuilders.get("/deletebook/1"))
                .andExpect(status().is3xxRedirection())
                .andExpect(redirectedUrl("/index"));

        verify(bookService,times(1)).deleteBook(1);
    }
}