bug: Real-time collaboration room sync via Firebase has no conflict resolution — two users typing simultaneously in the same room can produce garbled/merged code that neither user intended

[prince-pokharna]

🐛 Problem Statement

Debugra's README documents: "Real-Time Collaboration — Create rooms, share a Room ID, and code together with live Firebase sync." The useRoom hook syncs code changes via Firebase Realtime Database or Firestore. However, the current implementation appears to use last-write-wins synchronization: when two users type simultaneously, each keystroke is written to Firebase and the last write wins, causing:

• Lost keystrokes: User A types "function" while User B types "const" simultaneously. Depending on network timing, one user's changes are silently discarded.
• Garbled state: Interleaved writes from two users can produce syntactically invalid code like funccotnst ion that neither user wrote.
• No operational transformation or CRDT: Without OT/CRDT, any simultaneous edit is a race condition.

Proposed Fix

Implement Yjs (a battle-tested CRDT library) with Firebase as the sync backend:

// src/hooks/useRoom.js — replace raw Firebase write with Yjs

import * as Y from 'yjs';
import { FirebaseProvider } from 'y-firebase'; // or y-webrtc as fallback

const ydoc = new Y.Doc();
const yText = ydoc.getText('monaco');

// Connect Yjs document to Firebase for sync
const provider = new FirebaseProvider(firebaseDb, `rooms/${roomId}`, ydoc);

// Bind Monaco editor to Yjs document
import { MonacoBinding } from 'y-monaco';
new MonacoBinding(yText, monacoEditorRef.current.getModel(), new Set([monacoEditorRef.current]), provider.awareness);

Yjs's CRDT guarantees convergence — all users always reach the same final state regardless of write order or simultaneous edits. y-monaco provides a drop-in binding for Monaco Editor that requires no changes to the editor itself.

Dependencies to add:

npm install yjs y-firebase y-monaco

Files to Modify

File	Change
src/hooks/useRoom.js	Replace raw Firebase code writes with Yjs + FirebaseProvider
package.json	Add yjs, y-firebase, y-monaco

Suggested labels: bug, collaboration, frontend, level: advanced

I would like to work on this. Could you please assign it to me?

[prince-pokharna]

Hey @vijaypatil477 ,
Please assign it to me under GSSOC 2026.
/assign /claim

[Yuvraj-Sarathe]

@prince-pokharna and @vijaypatil477, I'm interested in working on this bug and have read the issue description. I'd like to volunteer to be assigned to this task and contribute to resolving the conflict resolution issue in real-time collaboration via Firebase.