Scrum Poker application

A small web application that allows users to quickly and easily start estimating user stories in dedicated rooms. It has been built to learn about websockets and realtime interactive experiences on the web.

Why create this?

When estimating user stories at work, we often use a website to submit estimations. The website we often use for this is scrumpoker-online.org. This works well, and really helps us to quickly estimate user stories. But it does have some limitations and annoyances.

• The temporary accounts are great, but don't allow for any customization by default
• It's full of ads, which are very distracting
• You cannot remove your estimate once you have one selected
  • It's only possible to remove all estimations for everyone
• It's not possible to join as a hidden user
  • This means that a project manager cannot join without being listed, which clutters up the overview

Overall, it's a nice website with some very good ideas. But there are some things that I would really like to see.

Creating the Scrum Poker application

Authentication

One of the best things about scrumpoker-online.org is, in my opinion, the authentication system. I really like how quickly you can create a temporary account and get started in seconds. That is something I really wanted to recreate. To do that, I created a users table with a token instead of a password. When creating a room, a user is created and the token will be stored as a cookie. This token is used to authenticate requests. When this cookie is cleared, it is no longer possible to use that user. This is no problem though, for multiple reasons:

• No personal data is stored at all
• Usernames do not have to be unique. Multiple users with the same username are allowed
• When a user has been inactive for a day, the user will get deleted in a cron

I think this is a great way to do authentication for this type of application. The goal is to get started quickly, and this makes it possible to just type a username and start sharing the room ID.

Rooms

With the authentication system decided, the next step was to decide on how to do rooms. This was also quite easy to do. A room has a UUID, which is a hex-encoded set of 16 bytes from the NodeJS crypto utility. Since rooms are temporary, it only serves to obscure the room URL. This is security by obscurity, of course. But again, there is no sensitive data here.

For cleanup, I extended the cron to check for rooms where the creator no longer exists. This check happens after the inactive users have gotten cleaned up. Doing this ensures that the database doesn't grow too large over time.

Websockets

Now that the application has both users and rooms, it was time to work on the interactivity. For this, I created a websocket endpoint in Go. I chose to do this in Go, because it's absolutely crucial to handle all edge cases. Go really helps with this, since errors are returned as values for most functions. This forces you to handle any potential error that might get returned at any point, and eliminates the need for try/ catch blocks which might get forgotten. Of course, edge cases can still happen, but this helps me handle a lot of them early.

The Scrum Poker Application

In the end, I'm very happy with the result. It's exactly what I was looking for. It's very quick and easy to get started, and there's a lot of customization options.

The site is available on scrum-poker.connor.nl.