[20210420] Assertions.assertThatThrownBy, Entity Validation

[JuHyun419]

Assertions.assertThatThrownBy,

• 예외처리 검증 함수

// pom.xml
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-validation</artifactId>
</dependency>


// Comment Entity
import org.hibernate.validator.constraints.Length;
import javax.validation.constraints.NotBlank;

...
    @Length(max = 1000, message = "댓글은 1000자를 초과할 수 없습니다.")
    @NotBlank(message = "댓글 내용은 비어 있을 수 없습니다.")
    private String content;


// Test
import static org.assertj.core.api.Assertions.assertThatThrownBy;

...

    @DisplayName("[예외] 댓글 내용은 1000자를 넘어서는 안된다.")
    @Test
    void commentIsTooLong() {
        // given
        final String tooLongComment = RandomStringUtils.randomAlphanumeric(1010);

        // when
        CommentCreateRequest request = CommentCreateRequest.builder()
                .content(tooLongComment)
                .lectureId(testLecture.getId())
                .userId(testUser.getId())
                .build();

        // then
        assertThatThrownBy(() -> commentService.createComment(request.toEntity(), request.getUserId(), request.getLectureId()))
                .isInstanceOf(ConstraintViolationException.class)
                .hasMessageContaining("1000자");
    }