I say this as a developer who uses ruby as my primary language - Can we just please cut it out with the coffeescript in these tutorials? It just adds another level of complexity on top of the tutorial. Everybody already knows javascript, just write your examples in that. Instead, in addition to absorbing the Angular portion of this tutorial, I also have to mentally translate everything from coffeescript to javascript, which makes learning this stuff harder.
Javascript is the lingua franca of frontend web development. Stick to that.