diff --git a/walkguide-backend/demo/src/test/java/com/walkguide/service/FcmServiceTest.java b/walkguide-backend/demo/src/test/java/com/walkguide/service/FcmServiceTest.java
new file mode 100644
index 0000000..7f09c68
--- /dev/null
+++ b/walkguide-backend/demo/src/test/java/com/walkguide/service/FcmServiceTest.java
@@ -0,0 +1,127 @@
+package com.walkguide.service;
+
+import org.junit.jupiter.api.BeforeEach;
+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.junit.jupiter.MockitoExtension;
+
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.*;
+
+/**
+ * Unit test untuk FcmService.
+ *
+ * FcmService saat ini berjalan dalam mode LOG-ONLY (tidak mengirim FCM nyata),
+ * sehingga test di sini memastikan:
+ *  1. Metode tidak melempar exception dalam kondisi normal
+ *  2. Metode gracefully handle token kosong / null
+ *  3. sendHighPriority mendelegasikan ke sendToToken tanpa error
+ */
+@ExtendWith(MockitoExtension.class)
+@DisplayName("FcmService Unit Tests")
+class FcmServiceTest {
+
+    @InjectMocks
+    FcmService fcmService;
+
+    private static final String VALID_TOKEN = "fcm-token-abc123xyz";
+    private static final String TITLE = "Test Title";
+    private static final String BODY = "Test Body";
+    private static final Map<String, String> DATA = Map.of("type", "TEST");
+
+    // ===== sendToToken TESTS =====
+
+    @Test
+    @DisplayName("sendToToken - token valid harus tidak throw exception")
+    void sendToToken_validToken_shouldNotThrow() {
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendToToken(VALID_TOKEN, TITLE, BODY, DATA));
+    }
+
+    @Test
+    @DisplayName("sendToToken - token null harus tidak throw exception (skip gracefully)")
+    void sendToToken_nullToken_shouldNotThrow() {
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendToToken(null, TITLE, BODY, DATA));
+    }
+
+    @Test
+    @DisplayName("sendToToken - token kosong/blank harus tidak throw exception")
+    void sendToToken_blankToken_shouldNotThrow() {
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendToToken("", TITLE, BODY, DATA));
+
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendToToken("   ", TITLE, BODY, DATA));
+    }
+
+    @Test
+    @DisplayName("sendToToken - data null harus tidak throw exception")
+    void sendToToken_nullData_shouldNotThrow() {
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendToToken(VALID_TOKEN, TITLE, BODY, null));
+    }
+
+    @Test
+    @DisplayName("sendToToken - data kosong (empty map) harus tidak throw exception")
+    void sendToToken_emptyData_shouldNotThrow() {
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendToToken(VALID_TOKEN, TITLE, BODY, Map.of()));
+    }
+
+    @Test
+    @DisplayName("sendToToken - title null harus tidak throw exception")
+    void sendToToken_nullTitle_shouldNotThrow() {
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendToToken(VALID_TOKEN, null, BODY, DATA));
+    }
+
+    @Test
+    @DisplayName("sendToToken - body null harus tidak throw exception")
+    void sendToToken_nullBody_shouldNotThrow() {
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendToToken(VALID_TOKEN, TITLE, null, DATA));
+    }
+
+    // ===== sendHighPriority TESTS =====
+
+    @Test
+    @DisplayName("sendHighPriority - token valid harus tidak throw exception")
+    void sendHighPriority_validToken_shouldNotThrow() {
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendHighPriority(VALID_TOKEN, TITLE, BODY, DATA));
+    }
+
+    @Test
+    @DisplayName("sendHighPriority - token null harus tidak throw exception")
+    void sendHighPriority_nullToken_shouldNotThrow() {
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendHighPriority(null, TITLE, BODY, DATA));
+    }
+
+    @Test
+    @DisplayName("sendHighPriority - token kosong harus tidak throw exception")
+    void sendHighPriority_blankToken_shouldNotThrow() {
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendHighPriority("", TITLE, BODY, null));
+    }
+
+    @Test
+    @DisplayName("sendHighPriority - data SOS payload besar harus ditangani tanpa error")
+    void sendHighPriority_sosBigPayload_shouldNotThrow() {
+        Map<String, String> sosData = Map.of(
+                "type", "SOS_TRIGGERED",
+                "sosId", "12345",
+                "userId", "99",
+                "lat", "-7.257472",
+                "lng", "112.752088",
+                "address", "Jl. Kenangan No. 1, Surabaya"
+        );
+
+        assertThatNoException().isThrownBy(() ->
+                fcmService.sendHighPriority(VALID_TOKEN, "SOS Darurat!", "Pengguna membutuhkan bantuan", sosData));
+    }
+}
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