diff --git a/src/main/java/gift/auth/AuthenticationResolver.java b/src/main/java/gift/auth/AuthenticationResolver.java
index cb428c53..05403337 100644
--- a/src/main/java/gift/auth/AuthenticationResolver.java
+++ b/src/main/java/gift/auth/AuthenticationResolver.java
@@ -26,7 +26,7 @@ public Member extractMember(String authorization) {
             final String email = jwtProvider.getEmail(token);
             return memberService.findByEmail(email).orElse(null);
         } catch (Exception e) {
-            return null;
+            throw new UnauthorizedException("유효하지 않은 토큰입니다");
         }
     }
 }
diff --git a/src/main/java/gift/auth/GlobalExceptionHandler.java b/src/main/java/gift/auth/GlobalExceptionHandler.java
new file mode 100644
index 00000000..340d5a69
--- /dev/null
+++ b/src/main/java/gift/auth/GlobalExceptionHandler.java
@@ -0,0 +1,14 @@
+package gift.auth;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@RestControllerAdvice
+public class GlobalExceptionHandler {
+
+    @ExceptionHandler(UnauthorizedException.class)
+    public ResponseEntity<Void> handleUnauthorized(UnauthorizedException e) {
+        return ResponseEntity.status(401).build();
+    }
+}
diff --git a/src/main/java/gift/auth/UnauthorizedException.java b/src/main/java/gift/auth/UnauthorizedException.java
new file mode 100644
index 00000000..6e0e11bc
--- /dev/null
+++ b/src/main/java/gift/auth/UnauthorizedException.java
@@ -0,0 +1,7 @@
+package gift.auth;
+
+public class UnauthorizedException extends RuntimeException {
+    public UnauthorizedException(String message) {
+        super(message);
+    }
+}
diff --git a/src/test/java/gift/auth/AuthenticationResolverTest.java b/src/test/java/gift/auth/AuthenticationResolverTest.java
new file mode 100644
index 00000000..b3df31a1
--- /dev/null
+++ b/src/test/java/gift/auth/AuthenticationResolverTest.java
@@ -0,0 +1,75 @@
+package gift.auth;
+
+import gift.member.MemberService;
+import io.restassured.RestAssured;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.server.LocalServerPort;
+import org.springframework.test.context.jdbc.Sql;
+
+import static org.hamcrest.Matchers.notNullValue;
+
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+class AuthenticationResolverTest {
+
+    @LocalServerPort
+    int port;
+
+    @Autowired
+    JwtProvider jwtProvider;
+
+    @Autowired
+    MemberService memberService;
+
+    @BeforeEach
+    void setUp() {
+        RestAssured.port = port;
+    }
+
+    @Test
+    @Sql(scripts = "/data/truncate.sql",
+         executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+    void 잘못된_토큰으로_요청하면_401() {
+        RestAssured
+            .given()
+                .header("Authorization", "Bearer invalid-token")
+            .when()
+                .get("/api/wishes")
+            .then()
+                .statusCode(401);
+    }
+
+    @Test
+    @Sql(scripts = "/data/truncate.sql",
+         executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+    void 유효한_토큰이지만_회원이_없으면_401() {
+        String token = jwtProvider.createToken("nonexistent@example.com");
+
+        RestAssured
+            .given()
+                .header("Authorization", "Bearer " + token)
+            .when()
+                .get("/api/wishes")
+            .then()
+                .statusCode(401);
+    }
+
+    @Test
+    @Sql(scripts = "/data/truncate.sql",
+         executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+    void 유효한_토큰과_회원이_존재하면_200() {
+        memberService.create("valid@example.com");
+        String token = jwtProvider.createToken("valid@example.com");
+
+        RestAssured
+            .given()
+                .header("Authorization", "Bearer " + token)
+            .when()
+                .get("/api/wishes")
+            .then()
+                .statusCode(200)
+                .body(notNullValue());
+    }
+}
diff --git a/src/test/java/gift/category/CategoryServiceTest.java b/src/test/java/gift/category/CategoryServiceTest.java
new file mode 100644
index 00000000..518bbd35
--- /dev/null
+++ b/src/test/java/gift/category/CategoryServiceTest.java
@@ -0,0 +1,40 @@
+package gift.category;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.jdbc.Sql;
+
+import java.util.NoSuchElementException;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+@SpringBootTest
+class CategoryServiceTest {
+
+    @Autowired
+    CategoryService categoryService;
+
+    @Test
+    @Sql(scripts = {"/data/truncate.sql", "/data/seed/find_category_by_id.sql"},
+         executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+    void 존재하는_ID로_엔티티를_조회하면_카테고리를_반환한다() {
+        Category category = categoryService.findEntityById(1L);
+
+        assertThat(category.getId()).isEqualTo(1L);
+        assertThat(category.getName()).isEqualTo("전자기기");
+        assertThat(category.getColor()).isEqualTo("#1E90FF");
+        assertThat(category.getImageUrl()).isEqualTo("https://example.com/images/electronics.jpg");
+        assertThat(category.getDescription()).isEqualTo("전자기기 카테고리");
+    }
+
+    @Test
+    @Sql(scripts = {"/data/truncate.sql"},
+         executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+    void 존재하지_않는_ID로_엔티티를_조회하면_예외가_발생하고_메시지에_ID가_포함된다() {
+        assertThatThrownBy(() -> categoryService.findEntityById(999L))
+            .isInstanceOf(NoSuchElementException.class)
+            .hasMessageContaining("999");
+    }
+}
diff --git a/src/test/resources/data/seed/delete_member_success.sql b/src/test/resources/data/seed/delete_member_success.sql
new file mode 100644
index 00000000..12669c47
--- /dev/null
+++ b/src/test/resources/data/seed/delete_member_success.sql
@@ -0,0 +1,3 @@
+-- seed for: delete_member_success
+INSERT INTO member (id, email, password, point)
+VALUES (1, 'delete-target@example.com', 'password123', 0);
diff --git a/src/test/resources/data/seed/find_category_by_id.sql b/src/test/resources/data/seed/find_category_by_id.sql
new file mode 100644
index 00000000..ae517460
--- /dev/null
+++ b/src/test/resources/data/seed/find_category_by_id.sql
@@ -0,0 +1,2 @@
+INSERT INTO category (id, name, color, image_url, description)
+VALUES (1, '전자기기', '#1E90FF', 'https://example.com/images/electronics.jpg', '전자기기 카테고리');