Collaborative document editor that allows 1+ users editting the same document simultaneously. Syncing document state across server and clients is done through my implementation of operational transformation. Think Google Docs, but in a code editor with infinitely less features than you'd need. Proof of concept project.

I initially undertook this project in college in the summer of 2022. I achieved a near perfect solution then, but a few edge case bugs had eluded me and I took a break from the project out of frustration. 2 years later, my implementation of operational transformation is functionally near perfect, if not perfect. While the transformation engine and data model were at its largely developed during my formative years in college and were therefore horribly thought through -- it works. Perhaps someday I will come back to rewrite the transformation engine in a manner that doesn't make me cringe, but that day is not today. Nor tommorrow. Give me another 2 years perhaps :)

If you're interested in undertaking a side project more intellectually stimulating than a portfolio website and are a macochist when it comes to headaches, then give operational transformation a try. Close your browser tab, develop a high-level understanding of distributed document syncing, and hit the ground running (or crawling as it was in my case) on your own implementation. I promise this will be one of the most difficult problems you'll ever undertake independently. Not quite as difficult as exiting vim however.

Simultaneous document editing is the goal. This means that you need a process that can sync document state in real time between 2+ clients with zero tolerance for mistakes. If there was no latency between clients, then this would be accomplished automatically, no different than multiple keyboards attached to the same computer editting the same local document. However, latency causes the intention and natural causality of document changes to be lost. In other terms, two conccurent operations can be executed in different orders on two different clients editting the same document -- which compounds with more concurrent operations and leads to divergent documents states.

Update SignalrConnection.ts with the IP address of the device on your network running the backend.

cd client && yarn && npm start

Access webpage using any browser at YOUR_IP:3000

Install .NET core 8

cd server/src && dotnet build && dotnet run

Alternatively, vscode is configured to be able to launch the backend in debugging mode.

• React (CRA), Typescript, Jest, SignalR websockets, Monaco Code Editor library
• dotnet, SignalR websockets, xunit

• Write up documentation on how I am resolving document state conflicts.
• Refactor transformer
• Refactor data model to be startIndex, endIndex. Instead of column and line based ??
• Investigate if resolving conflicting ranges requires a possible introduction of secondary operation
• Double check that the How to run steps are actually correct lol