feat: enforce authentication on sendChat() with three-layer guard

미인증 상태에서 sendChat() 호출 시 AuthenticationException으로 즉시 실패하도록
SOOPChatClient, SOOPConnection, WebSocketManager에 인증 검사를 추가.
읽기 전용(이벤트 수신)은 인증 없이 유지.

Author: getCurrentThread

README.md

@@ -103,9 +103,6 @@ public class Example {
 
         chat.connectToChat().join();
 
-        // 채팅 전송
-        chat.sendChat("Hello!");
-
         // 프로그램 실행 유지
         Thread.sleep(Long.MAX_VALUE);
     }
@@ -139,14 +136,33 @@ public class DirectExample {
 }
 ```
 
-### 인증 (선택사항)
+### 인증 (채팅 전송 시 필수)
+
+읽기 전용(이벤트 수신)은 인증 없이 사용할 수 있지만, `sendChat()`으로 채팅을 전송하려면 반드시 인증이 필요합니다.
 
 ```java
 SoopClient client = new SoopClient();
 
+// 1. 로그인
 AuthCookie cookie = client.auth.signIn("userId", "password").join();
 if (cookie.success()) {
     System.out.println("로그인 성공");
+
+    // 2. 인증된 설정으로 채팅 클라이언트 생성
+    SOOPChatConfig config = new SOOPChatConfig.Builder()
+            .bid("streamerId")
+            .authCookie(cookie)
+            .build();
+
+    SOOPChatClient chat = new SOOPChatClient(config);
+
+    chat.on(ChatEvent.CHAT_MESSAGE, (ChatMessageEvent e) -> {
+        System.out.println(e.senderNickname() + ": " + e.message());
+    });
+
+    // 3. 연결 후 채팅 전송
+    chat.connectToChat().join();
+    chat.sendChat("Hello!").join();
 }
 ```
 

lib/src/main/java/com/github/getcurrentthread/soopapi/client/SOOPChatClient.java

@@ -14,6 +14,7 @@
 import com.github.getcurrentthread.soopapi.event.EventEmitter;
 import com.github.getcurrentthread.soopapi.event.EventListener;
 import com.github.getcurrentthread.soopapi.event.model.BaseEvent;
+import com.github.getcurrentthread.soopapi.exception.AuthenticationException;
 import com.github.getcurrentthread.soopapi.exception.ConnectionException;
 import com.github.getcurrentthread.soopapi.util.SOOPChatUtils;
 
@@ -98,6 +99,10 @@ public void connectToChattingBlocking() throws ConnectionException {
     }
 
     public CompletableFuture<Void> sendChat(String message) {
+        if (!config.isAuthenticated()) {
+            return CompletableFuture.failedFuture(
+                    new AuthenticationException("인증이 필요합니다. 채팅을 전송하려면 AuthCookie를 설정하세요."));
+        }
         if (connection == null || !isConnected) {
             return CompletableFuture.failedFuture(
                     new IllegalStateException("연결이 되어 있지 않습니다. 먼저 connectToChat을 호출하세요."));

lib/src/main/java/com/github/getcurrentthread/soopapi/connection/SOOPConnection.java

@@ -10,6 +10,7 @@
 import com.github.getcurrentthread.soopapi.event.ChatEvent;
 import com.github.getcurrentthread.soopapi.event.EventEmitter;
 import com.github.getcurrentthread.soopapi.event.model.JoinChannelEvent;
+import com.github.getcurrentthread.soopapi.exception.AuthenticationException;
 import com.github.getcurrentthread.soopapi.exception.ConnectionException;
 import com.github.getcurrentthread.soopapi.model.ChannelInfo;
 import com.github.getcurrentthread.soopapi.util.SOOPChatUtils;
@@ -161,6 +162,10 @@ public CompletableFuture<Void> reconnect() {
     }
 
     public CompletableFuture<Void> sendChat(String message) {
+        if (!config.isAuthenticated()) {
+            return CompletableFuture.failedFuture(
+                    new AuthenticationException("인증이 필요합니다. 채팅을 전송하려면 AuthCookie를 설정하세요."));
+        }
         return webSocketManager.sendChat(message);
     }
 

lib/src/main/java/com/github/getcurrentthread/soopapi/exception/AuthenticationException.java

@@ -0,0 +1,24 @@
+package com.github.getcurrentthread.soopapi.exception;
+
+/** 인증이 필요한 작업을 미인증 상태에서 시도할 때 발생하는 예외입니다. */
+public class AuthenticationException extends SOOPChatException {
+
+    /**
+     * 지정된 메시지로 새 AuthenticationException을 구성합니다.
+     *
+     * @param message 예외 메시지
+     */
+    public AuthenticationException(String message) {
+        super(message);
+    }
+
+    /**
+     * 지정된 메시지와 원인으로 새 AuthenticationException을 구성합니다.
+     *
+     * @param message 예외 메시지
+     * @param cause 원인 (null 허용)
+     */
+    public AuthenticationException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

lib/src/main/java/com/github/getcurrentthread/soopapi/websocket/WebSocketManager.java

@@ -14,6 +14,7 @@
 import javax.net.ssl.SSLContext;
 
 import com.github.getcurrentthread.soopapi.config.SOOPChatConfig;
+import com.github.getcurrentthread.soopapi.exception.AuthenticationException;
 import com.github.getcurrentthread.soopapi.model.ChannelInfo;
 import com.github.getcurrentthread.soopapi.util.SSLContextProvider;
 
@@ -356,6 +357,10 @@ public boolean isConnected() {
     }
 
     public CompletableFuture<Void> sendChat(String message) {
+        if (!config.isAuthenticated()) {
+            return CompletableFuture.failedFuture(
+                    new AuthenticationException("인증이 필요합니다. 채팅을 전송하려면 AuthCookie를 설정하세요."));
+        }
         if (!isConnected() || webSocket == null) {
             return CompletableFuture.failedFuture(
                     new IllegalStateException("WebSocket is not connected"));

lib/src/test/java/com/github/getcurrentthread/soopapi/client/SOOPChatClientTest.java

@@ -1,7 +1,10 @@
 package com.github.getcurrentthread.soopapi.client;
 
+import static org.junit.jupiter.api.Assertions.*;
+
 import java.util.Arrays;
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.logging.ConsoleHandler;
 import java.util.logging.Level;
@@ -12,9 +15,11 @@
 import org.junit.jupiter.api.Tag;
 import org.junit.jupiter.api.Test;
 
+import com.github.getcurrentthread.soopapi.api.model.AuthCookie;
 import com.github.getcurrentthread.soopapi.config.SOOPChatConfig;
 import com.github.getcurrentthread.soopapi.event.ChatEvent;
 import com.github.getcurrentthread.soopapi.event.model.ChatMessageEvent;
+import com.github.getcurrentthread.soopapi.exception.AuthenticationException;
 import com.github.getcurrentthread.soopapi.model.ChannelInfo;
 import com.github.getcurrentthread.soopapi.util.SOOPChatUtils;
 
@@ -127,4 +132,56 @@ public void testSOOPChatClientConnection() throws Exception {
             LOGGER.info("Test completed.");
         }
     }
+
+    @Test
+    void sendChat_withoutAuth_throwsAuthenticationException() {
+        SOOPChatConfig config =
+                new SOOPChatConfig.Builder().bid("testStreamer").bno("12345").build();
+
+        SOOPChatClient client = new SOOPChatClient(config);
+
+        ExecutionException ex =
+                assertThrows(ExecutionException.class, () -> client.sendChat("Hello!").get());
+
+        assertInstanceOf(AuthenticationException.class, ex.getCause());
+    }
+
+    @Test
+    void sendChat_withFailedAuthCookie_throwsAuthenticationException() {
+        AuthCookie failedCookie =
+                new AuthCookie(
+                        "user", false, "", null, null, null, null, null, null, null, null, null,
+                        null);
+
+        SOOPChatConfig config =
+                new SOOPChatConfig.Builder()
+                        .bid("testStreamer")
+                        .bno("12345")
+                        .authCookie(failedCookie)
+                        .build();
+
+        SOOPChatClient client = new SOOPChatClient(config);
+
+        ExecutionException ex =
+                assertThrows(ExecutionException.class, () -> client.sendChat("Hello!").get());
+
+        assertInstanceOf(AuthenticationException.class, ex.getCause());
+    }
+
+    @Test
+    void sendChat_withoutAuth_prioritizesAuthOverConnection() {
+        SOOPChatConfig config =
+                new SOOPChatConfig.Builder().bid("testStreamer").bno("12345").build();
+
+        SOOPChatClient client = new SOOPChatClient(config);
+
+        // 미연결 + 미인증 상태에서 인증 오류가 먼저 발생해야 함
+        assertFalse(client.isConnected());
+
+        ExecutionException ex =
+                assertThrows(ExecutionException.class, () -> client.sendChat("Hello!").get());
+
+        assertInstanceOf(
+                AuthenticationException.class, ex.getCause(), "연결 오류가 아닌 인증 오류가 먼저 발생해야 합니다");
+    }
 }