fix: use optional chaining

src/services/dto/KakaoResponse.ts

@@ -70,7 +70,7 @@ const toPiickleAgeGroup = (ageGroup: string): AgeGroup => {
 
 const kakaoToPiickleUser = (kakaoUser: KakaoResponse): IUser => {
   const nickname =
-    kakaoUser.kakao_account.profile.nickname || `kakao ${kakaoUser.id}`;
+    kakaoUser.kakao_account?.profile?.nickname ?? `kakao ${kakaoUser.id}`;
   const profileImageUrl =
     kakaoUser.kakao_account.profile.profile_image_url ||
     config.defaultProfileImgUrl;

test/userConverter.spec.ts

@@ -0,0 +1,39 @@
+import KakaoResponse, {
+  kakaoToPiickleUser
+} from '../src/services/dto/KakaoResponse';
+import { expect } from 'chai';
+
+describe('kakaoToPiickleUser', () => {
+  it('should return IUser', () => {
+    const kakaoUser: KakaoResponse = {
+      id: '1234',
+      kakao_account: {
+        profile_nickname_needs_agreement: true,
+        profile_image_needs_agreement: true,
+        profile: {
+          // nickname: 'nickname',
+          thumbnail_image_url: 'kakao',
+          profile_image_url: 'kakao',
+          is_default_image: true
+        },
+        has_email: true,
+        email_needs_agreement: true,
+        is_email_valid: true,
+        is_email_verified: true,
+        email: 'kakao',
+        has_age_range: true,
+        age_range_needs_agreement: true,
+        age_range: '20~29',
+        has_birthday: true,
+        birthday_needs_agreement: true,
+        birthday: '1103',
+        birthday_type: 'SOLAR',
+        has_gender: true,
+        gender_needs_agreement: true,
+        gender: 'female'
+      }
+    };
+    const convertedUser = kakaoToPiickleUser(kakaoUser);
+    expect(convertedUser.nickname).equals('kakao 1234');
+  });
+});