MockMvc 테스트 body가 '<no character encoding set>' 인경우

@WebMvc 테스트 중 Request Body 데이터가 나오지 않는 상황이 발생.

MockHttpServletRequest:
      HTTP Method = POST
      Request URI = /api/v1/items
       Parameters = {_csrf=[89d3f355-ea84-4108-b910-eebcb6795735]}
          Headers = [Content-Type:"application/json", Accept:"application/json", Content-Length:"505"]
             Body = <no character encoding set> // 
    Session Attrs = {}

Handler:
         Type = com.prgrms.bdbks.domain.item.api.ItemController
         Method = com.prgrms.bdbks.domain.item.api.ItemController#createItem(ItemCreateRequest)

Body = <no character encoding set>

RequestBuilder 속성에 characterEncoding(StandardCharsets.UTF_8) 또는 .characterEncoding("utf-8") 를 추가해주면 된다

mockMvc.perform(post(BASE_REQUEST_URI)
                .with(csrf())
                .contentType(MediaType.APPLICATION_JSON)
                .accept(MediaType.APPLICATION_JSON)

                .characterEncoding(StandardCharsets.UTF_8) // here

                .content(objectMapper.writeValueAsString(request)
                )
            ).andDo(print())
            .andExpect(status().isCreated());