KL-72/test: add city service test code

src/test/java/taco/klkl/domain/region/service/CityServiceImplTest.java

@@ -0,0 +1,36 @@
+package taco.klkl.domain.region.service;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import taco.klkl.domain.region.dao.CityRepository;
+
+@ExtendWith(MockitoExtension.class)
+public class CityServiceImplTest {
+
+	@InjectMocks
+	CityServiceImpl cityService;
+
+	@Mock
+	CityRepository cityRepository;
+
+	@Test
+	@DisplayName("id로 도시 존재 여부 확인 테스트")
+	void isExitsCity_True() {
+		// given
+		when(cityRepository.existsById(1L)).thenReturn(true);
+
+		// when
+		boolean result = cityService.exitsCityById(1L);
+
+		// then
+		assertThat(result).isTrue();
+	}
+}