Handle null state in cursor

frontend/src/components/headers/UserPresenceList.tsx

@@ -35,6 +35,8 @@ function UserPresenceList(props: UserPresenceListProps) {
 
 	const handleScrollToUserLocation = (presence: Presence) => {
 		const cursor = presence.presence.cursor;
+		if (cursor === null) return;
+
 		editorStore.cmView?.dispatch({
 			effects: EditorView.scrollIntoView(cursor[0], {
 				y: "center",

frontend/src/hooks/useYorkieDocument.ts

@@ -47,7 +47,7 @@ export const useYorkieDocument = (
 					name: presenceName,
 					color: Color(randomColor()).fade(0.15).toString(),
 					selection: null,
-					cursor: [0, 0],
+					cursor: null,
 				},
 			});
 		},

frontend/src/utils/yorkie/remoteSelection.ts

@@ -1,17 +1,15 @@
-import * as cmView from "@codemirror/view";
-
 import * as cmState from "@codemirror/state";
+import * as cmView from "@codemirror/view";
 import * as dom from "lib0/dom";
 import * as pair from "lib0/pair";
+import _ from "lodash";
 import * as yorkie from "yorkie-js-sdk";
-
 import {
-	YorkieSyncConfig,
 	YorkieCodeMirrorDocType,
 	YorkieCodeMirrorPresenceType,
+	YorkieSyncConfig,
 	yorkieSyncFacet,
 } from "./yorkieSync.js";
-import _ from "lodash";
 
 export const yorkieRemoteSelectionsTheme = cmView.EditorView.baseTheme({
 	".cm-ySelection": {},
@@ -162,6 +160,7 @@ export class YorkieRemoteSelectionsPluginValue {
 			} else if (presence.get("selection")) {
 				presence.set({
 					selection: null,
+					cursor: null,
 				});
 			}
 		});

frontend/src/utils/yorkie/yorkieSync.ts

@@ -10,7 +10,7 @@ export type YorkieCodeMirrorPresenceType = {
 	color: string;
 	name: string;
 	selection: yorkie.TextPosStructRange | null;
-	cursor: [number, number];
+	cursor: [number, number] | null;
 };
 
 export class YorkieSyncConfig<