CoffeeScript was a welcome addition when it first arrived. Nowadays though, I am finding its benefits are decreasing, and its drawbacks are increasing. I plan to no longer use CoffeeScript in my future projects, here is why.

I’ve tweeted about this here and there, and today someone asked me why. So I thought I’d blog it out.

##EcmaScript 6 Has the Key CoffeeScript Features I Like

arrow functions, destructuring assignment and shorthand object literals are my favorite features of CoffeeScript. They are all in EcmaScript 6. This is the biggest reason why CoffeeScript is becoming less relevant to me. For sure, ES6 has a ways to go and not even Node has these features yet. But by the time my current project is done, Node’s Harmony support will likely meet my needs.

##EcmaScript 6 Has None of the CoffeeScript Features I Hate

I hate significant whitespace, and always have. I downright think it’s wrong. I grudgingly accepted it when adopting CoffeeScript. I really look forward to no longer dealing with it.

As my project grows in size, significant whitespace becomes more and more of a problem. It’s just plain not readable or visually parsable. Your files become a wall of dense text. Damn you Python, damn you to hell!

Using CoffeeScript has also made me dislike implicit return. Saving one keyword is not worth this:

module((provide) -> provide.value('foo', bar) return # <-- bleh ) 

without return (or null or undefined, all ugly), the return value is provide.value()s return value (a function), which is not what module() wants here (leading to an error). I often have to do this to avoid loops becoming unneeded expressions too. The real problem here though is not the ugliness, but the occassional surprises. I don’t even use implicit return, so a double whammy for me.

##EcmaScript 5 is Ubiquitous for Me

I have to support IE8 at work, but not at home. ES5’s features (especially the array functions) negate even more of CoffeeScript’s features for me. CoffeeScript compiling all of its loop constructs into a standard for loop is a nice little bonus though.

##Open Source Code is Better Written in JavaScript

If you’re contributing to the JS community, you’re better off writing in JavaScript. More people will contribute and/or adopt your code.

##Tooling Support

Tooling support for CoffeeScript is pretty darn good. But it’s not perfect. It is perfect with JavaScript, it has to be. This is a minor point, but eliminating even a little bit of friction is a good thing. Tools all tend to support CoffeeScript just a little bit differently: where they dump the compiled JS, how to specify wrap, etc.

Not having to grunt watch your JS is another minor win.

##CoffeeScript Isn’t Irrelevant Yet

Even for me, and it won’t be for a while yet. But I do suspect I’m on my last CS project. If you need to support old IEs, want to use PhantomJS, etc, then CS is still very welcome.