Spring Test How to test a JSON Array in jsonPath

In Spring, we can use Hamcrest APIs like hasItem and hasSize to test a JSON Array. Review the following example :

package com.mkyong;
import org.junit.Test;
import org.junit.runner.RunWith;
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.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.test.context.ActiveProfiles;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import static org.hamcrest.Matchers.*;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureMockMvc
@ActiveProfiles("test")
public class BookControllerTest {
    @Autowired
    private MockMvc mockMvc;
    @MockBean
    private BookRepository mockRepository;
    /*
            "timestamp":"2019-03-05T09:34:13.280+0000",
            "status":400,
            "errors":["Author is not allowed.","Please provide a price","Please provide a author"]
     */
    //article : jsonpath in array
    @Test
    public void save_emptyAuthor_emptyPrice_400() throws Exception {
        String bookInJson = "{\"name\":\"ABC\"}";
        mockMvc.perform(post("/books")
                .content(bookInJson)
                .header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON))
                .andDo(print())
                .andExpect(status().isBadRequest())
                .andExpect(jsonPath("$.timestamp", is(notNullValue())))
                .andExpect(jsonPath("$.status", is(400)))
                .andExpect(jsonPath("$.errors").isArray())
                .andExpect(jsonPath("$.errors", hasSize(3)))
                .andExpect(jsonPath("$.errors", hasItem("Author is not allowed.")))
                .andExpect(jsonPath("$.errors", hasItem("Please provide a author")))
                .andExpect(jsonPath("$.errors", hasItem("Please provide a price")));
        verify(mockRepository, times(0)).save(any(Book.class));

P.S Tested with Spring Boot 2