diff --git a/src/main/java/com/openisle/service/SearchService.java b/src/main/java/com/openisle/service/SearchService.java
index 3964da85a..271678bca 100644
--- a/src/main/java/com/openisle/service/SearchService.java
+++ b/src/main/java/com/openisle/service/SearchService.java
@@ -67,7 +67,7 @@ public class SearchService {
                                     "post",
                                     p.getId(),
                                     p.getTitle(),
-                                    p.getCategory().getName(),
+                                    p.getCategory() != null ? p.getCategory().getName() : null,
                                     extractSnippet(p.getContent(), keyword, false),
                                     null
                             )),
@@ -76,7 +76,7 @@ public class SearchService {
                                     "post_title",
                                     p.getId(),
                                     p.getTitle(),
-                                    p.getCategory().getName(),
+                                    p.getCategory() != null ? p.getCategory().getName() : null,
                                     extractSnippet(p.getContent(), keyword, true),
                                     null
                             ))
diff --git a/src/test/java/com/openisle/controller/NotificationControllerTest.java b/src/test/java/com/openisle/controller/NotificationControllerTest.java
index 53a8c80f8..d956b6eb9 100644
--- a/src/test/java/com/openisle/controller/NotificationControllerTest.java
+++ b/src/test/java/com/openisle/controller/NotificationControllerTest.java
@@ -47,7 +47,7 @@ class NotificationControllerTest {
                         .principal(new UsernamePasswordAuthenticationToken("alice","p")))
                 .andExpect(status().isOk())
                 .andExpect(jsonPath("$[0].id").value(1))
-                .andExpect(jsonPath("$[0].postId").value(2));
+                .andExpect(jsonPath("$[0].post.id").value(2));
     }
 
     @Test
diff --git a/src/test/java/com/openisle/controller/UserControllerTest.java b/src/test/java/com/openisle/controller/UserControllerTest.java
index d3d1b301c..4135281c1 100644
--- a/src/test/java/com/openisle/controller/UserControllerTest.java
+++ b/src/test/java/com/openisle/controller/UserControllerTest.java
@@ -81,7 +81,7 @@ class UserControllerTest {
         User u = new User();
         u.setId(2L);
         u.setUsername("bob");
-        Mockito.when(userService.findByUsername("bob")).thenReturn(Optional.of(u));
+        Mockito.when(userService.findByIdentifier("bob")).thenReturn(Optional.of(u));
 
         mockMvc.perform(get("/api/users/bob"))
                 .andExpect(status().isOk())
@@ -100,6 +100,7 @@ class UserControllerTest {
         post.setCreatedAt(java.time.LocalDateTime.now());
         post.setCategory(cat);
         post.setAuthor(user);
+        Mockito.when(userService.findByIdentifier("bob")).thenReturn(Optional.of(user));
         Mockito.when(postService.getRecentPostsByUser("bob", 10)).thenReturn(java.util.List.of(post));
 
         mockMvc.perform(get("/api/users/bob/posts"))
@@ -119,6 +120,7 @@ class UserControllerTest {
         comment.setCreatedAt(java.time.LocalDateTime.now());
         comment.setAuthor(user);
         comment.setPost(post);
+        Mockito.when(userService.findByIdentifier("bob")).thenReturn(Optional.of(user));
         Mockito.when(commentService.getRecentCommentsByUser("bob", 50)).thenReturn(java.util.List.of(comment));
 
         mockMvc.perform(get("/api/users/bob/replies"))
@@ -147,7 +149,7 @@ class UserControllerTest {
         comment.setAuthor(user);
         comment.setPost(post);
 
-        Mockito.when(userService.findByUsername("bob")).thenReturn(Optional.of(user));
+        Mockito.when(userService.findByIdentifier("bob")).thenReturn(Optional.of(user));
         Mockito.when(postService.getRecentPostsByUser("bob", 10)).thenReturn(java.util.List.of(post));
         Mockito.when(commentService.getRecentCommentsByUser("bob", 50)).thenReturn(java.util.List.of(comment));
 
diff --git a/src/test/java/com/openisle/integration/PublishModeIntegrationTest.java b/src/test/java/com/openisle/integration/PublishModeIntegrationTest.java
index 81ae82d11..d7755f6c0 100644
--- a/src/test/java/com/openisle/integration/PublishModeIntegrationTest.java
+++ b/src/test/java/com/openisle/integration/PublishModeIntegrationTest.java
@@ -36,8 +36,10 @@ class PublishModeIntegrationTest {
         rest.postForEntity("/api/auth/register", new HttpEntity<>(
                 Map.of("username", username, "email", email, "password", "pass123"), h), Map.class);
         User u = users.findByUsername(username).orElseThrow();
-        rest.postForEntity("/api/auth/verify", new HttpEntity<>(
-                Map.of("username", username, "code", u.getVerificationCode()), h), Map.class);
+        if (u.getVerificationCode() != null) {
+            rest.postForEntity("/api/auth/verify", new HttpEntity<>(
+                    Map.of("username", username, "code", u.getVerificationCode()), h), Map.class);
+        }
         ResponseEntity<Map> resp = rest.postForEntity("/api/auth/login", new HttpEntity<>(
                 Map.of("username", username, "password", "pass123"), h), Map.class);
         return (String) resp.getBody().get("token");
diff --git a/src/test/java/com/openisle/service/PasswordValidatorTest.java b/src/test/java/com/openisle/service/PasswordValidatorTest.java
index ba564491f..5b8a6d911 100644
--- a/src/test/java/com/openisle/service/PasswordValidatorTest.java
+++ b/src/test/java/com/openisle/service/PasswordValidatorTest.java
@@ -1,6 +1,7 @@
 package com.openisle.service;
 
 import com.openisle.model.PasswordStrength;
+import com.openisle.exception.FieldException;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.*;
@@ -11,7 +12,7 @@ class PasswordValidatorTest {
     void lowStrengthRequiresSixChars() {
         PasswordValidator validator = new PasswordValidator(PasswordStrength.LOW);
 
-        assertThrows(IllegalArgumentException.class, () -> validator.validate("12345"));
+        assertThrows(FieldException.class, () -> validator.validate("12345"));
         assertDoesNotThrow(() -> validator.validate("123456"));
     }
 
@@ -19,9 +20,9 @@ class PasswordValidatorTest {
     void mediumStrengthRules() {
         PasswordValidator validator = new PasswordValidator(PasswordStrength.MEDIUM);
 
-        assertThrows(IllegalArgumentException.class, () -> validator.validate("abc123"));
-        assertThrows(IllegalArgumentException.class, () -> validator.validate("abcdefgh"));
-        assertThrows(IllegalArgumentException.class, () -> validator.validate("12345678"));
+        assertThrows(FieldException.class, () -> validator.validate("abc123"));
+        assertThrows(FieldException.class, () -> validator.validate("abcdefgh"));
+        assertThrows(FieldException.class, () -> validator.validate("12345678"));
         assertDoesNotThrow(() -> validator.validate("abcd1234"));
     }
 
@@ -29,11 +30,11 @@ class PasswordValidatorTest {
     void highStrengthRules() {
         PasswordValidator validator = new PasswordValidator(PasswordStrength.HIGH);
 
-        assertThrows(IllegalArgumentException.class, () -> validator.validate("Abc123$"));
-        assertThrows(IllegalArgumentException.class, () -> validator.validate("abcd1234$xyz"));
-        assertThrows(IllegalArgumentException.class, () -> validator.validate("ABCD1234$XYZ"));
-        assertThrows(IllegalArgumentException.class, () -> validator.validate("AbcdABCDabcd"));
-        assertThrows(IllegalArgumentException.class, () -> validator.validate("Abcd1234abcd"));
+        assertThrows(FieldException.class, () -> validator.validate("Abc123$"));
+        assertThrows(FieldException.class, () -> validator.validate("abcd1234$xyz"));
+        assertThrows(FieldException.class, () -> validator.validate("ABCD1234$XYZ"));
+        assertThrows(FieldException.class, () -> validator.validate("AbcdABCDabcd"));
+        assertThrows(FieldException.class, () -> validator.validate("Abcd1234abcd"));
         assertDoesNotThrow(() -> validator.validate("Abcd1234$xyz"));
     }
 }