Adding ping message and pong event to RTM client

slack-api-client/src/main/java/com/slack/api/rtm/message/PingMessage.java

@@ -0,0 +1,21 @@
+package com.slack.api.rtm.message;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.time.Instant;
+
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class PingMessage implements RTMMessage {
+
+	public static final String TYPE_NAME = "ping";
+
+	private Long id;
+	private final String type = TYPE_NAME;
+	private Instant time;
+}

slack-api-client/src/test/java/test_with_remote_apis/methods/rtm_Test.java

@@ -11,9 +11,11 @@
 import com.slack.api.model.User;
 import com.slack.api.model.event.HelloEvent;
 import com.slack.api.model.event.MessageBotEvent;
+import com.slack.api.model.event.PongEvent;
 import com.slack.api.model.event.UserTypingEvent;
 import com.slack.api.rtm.*;
 import com.slack.api.rtm.message.Message;
+import com.slack.api.rtm.message.PingMessage;
 import com.slack.api.rtm.message.PresenceQuery;
 import com.slack.api.rtm.message.PresenceSub;
 import com.slack.api.rtm.message.Typing;
@@ -30,7 +32,9 @@
 import javax.websocket.DeploymentException;
 import java.io.IOException;
 import java.net.URISyntaxException;
+import java.time.Instant;
 import java.util.Arrays;
+import java.util.Objects;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import static org.hamcrest.CoreMatchers.*;
@@ -301,4 +305,49 @@ public void handle(String message) {
         assertThat(counter.get(), is(greaterThanOrEqualTo(5)));
     }
 
+
+    @Test
+    public void givenRTMClient_whenPing_ensureReceivesPong() throws Exception {
+
+        // given
+        SlackConfig config = new SlackConfig();
+        config.setLibraryMaintainerMode(false);
+        config.getHttpClientResponseHandlers().add(new JsonDataRecordingListener());
+        Slack slack = Slack.getInstance(config);
+
+        final Instant now = Instant.now();
+        final long pingId = now.toEpochMilli();
+
+        class PongReceived { PongEvent event = null; }
+        final PongReceived pongReceived = new PongReceived();
+
+        RTMEventsDispatcher dispatcher = RTMEventsDispatcherFactory.getInstance();
+        dispatcher.register(new RTMEventHandler<PongEvent>() {
+            @Override public void handle(PongEvent event) {
+                if (Objects.equals(event.getReply_to(), pingId)) {
+                    synchronized(pongReceived) {
+                        pongReceived.event = event;
+                        pongReceived.notifyAll();
+                    }
+                }
+            }
+        });
+
+        try (RTMClient rtm = slack.rtmStart(classicAppBotToken)) {
+            rtm.connect();
+            rtm.addMessageHandler(dispatcher.toMessageHandler());
+
+            // when
+            rtm.sendMessage(PingMessage.builder().id(pingId).time(now).build().toJSONString());
+
+            // ensure
+            synchronized(pongReceived) {
+                pongReceived.wait(5000L);
+            }
+            assertThat(pongReceived.event, notNullValue());
+            assertThat(pongReceived.event.getReply_to(), equalTo(pingId));
+            assertThat(pongReceived.event.getTime(), equalTo(now));
+        }
+
+    }
 }

slack-api-model/src/main/java/com/slack/api/model/event/PongEvent.java

@@ -0,0 +1,21 @@
+package com.slack.api.model.event;
+
+import lombok.Data;
+
+import java.time.Instant;
+
+/**
+ * The pong event is sent in response to a 'ping' message previously sent. The id and
+ * other fields will match that of the ping message.
+ * <p>
+ * https://api.slack.com/rtm
+ */
+@Data
+public class PongEvent implements Event
+{
+	public static final String TYPE_NAME = "pong";
+	private final String type = TYPE_NAME;
+
+	private final Long reply_to;
+	private final Instant time;
+}