You can see it in action below:
Click the canvas window and walk with arrows. Press "F" go go fullscreen.
There's nothing much to see here. I even didn't implement any collision.
The source code for the raycaster can be downloaded on github: https://github.com/rasmaxim/canvas-raycaster. As you may notice, it is heavily based on Lode Vandevennes's raycasting tutorial. I even left the same comments in. The code itself is awful, but it works.