[CLNP-6072] useConnectionHandler (#1291)

https://sendbird.atlassian.net/browse/SBISSUE-18182

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---------

Co-authored-by: HoonBaek <hoon@sendbird.com>

Author: chrisallo

src/hooks/useConnectionState.ts

@@ -0,0 +1,22 @@
+import { useState } from 'react';
+import { ConnectionState } from '@sendbird/chat';
+
+import ConnectionHandler from '../lib/handlers/ConnectionHandler';
+import useSendbirdStateContext from './useSendbirdStateContext';
+import uuidv4 from '../utils/uuid';
+
+export const useConnectionState = (): ConnectionState => {
+  const { stores } = useSendbirdStateContext();
+  const { sdkStore } = stores;
+  const { sdk } = sdkStore;
+
+  const [connectionState, setConnectionState] = useState(sdk.connectionState);
+  sdk.addConnectionHandler(uuidv4(), new ConnectionHandler({
+    onConnected: () => setConnectionState(ConnectionState.OPEN),
+    onDisconnected: () => setConnectionState(ConnectionState.CLOSED),
+    onReconnectStarted: () => setConnectionState(ConnectionState.CONNECTING),
+    onReconnectSucceeded: () => setConnectionState(ConnectionState.OPEN),
+    onReconnectFailed: () => setConnectionState(ConnectionState.CLOSED),
+  }));
+  return connectionState;
+};