I don't see how you can really use this without already being very familiar with Javascript. While you're writing your code you'd need to be constantly aware of how the code will be translated to js (so you can use the correct attributes and define datatypes correctly), and you'd also need to be aware of avoiding. NET library classes that can't be used by the translated js. It seems easier to just learn to manage large js projects.
The reason I'm looking for either C# / Scala JS compiler is that I'm a static typing fan, I am an old school developer who likes IDEs and like discovering API by pressing ctrl+space, instead of mentally knowing it or constantly checking the API docs, I know it's against the trend, and not considered cool, but this gets me working software out the door. I'm much more productive and have much less bugs while writing old school, unpopular Java, and using the IDE's (eclipse) sugar features. Scala is now my favorite language (I really hope it was a little more new dev friendly, it can become very syntax overwhelming sometimes) as I can many of the functional features in Ruby / Python / JavaScript / Clojure, but still stay in Static Java land.
Another thing static typing gives me that I really wish I had in JavaScript, is (almost) worry free refactoring.
In Java, I can extract methods, constants, delegates, change method signatures, rename members, fix typos in code, and never to worry I copy pasted something wrong.
I have yet to find such a way to do it safely in JavaScript / CoffeScript or any other dynamically typed language. (feel free to point if I'm missing something, I said I'm not that a great of a developer)
So maybe I'm just not good enough as a developer, but I like IDEs to protect me, perhaps I'm not smart enough to use VIM / Emacs / TextMate, and I can't memorize APIs. Static typing + functional features make me the most productive.
So C# / Scala / Java 8 javascript compilers are on the top of my wish list.
I hear you, but I can't agree. Maybe it's my background. For 13 years as a professional developer my primary languages were Perl and Javascript, using Vim and the Unix command-line as my IDE. For the past 1.5 years I've swapped C# for Perl and Visual Studio for my IDE (still have a vi emulator though.) Intellisense is definitely useful, but I find it gets in the way a lot... both literally by overlapping the code around the code I'm typing, and figuratively by trying to insert text while I type which causes me to double-type characters and backspace a lot. It does help with remembering (not learning) APIs, but that's one of my concerns about translating to js: Intellisense won't know which APIs are usable and which ones are not. If you're a C# developer who's dependent on Intellisense, it's going to mislead you here.
Regarding refactoring, it's hardly worry free for me. I always have to double check what VS is going to do when I use its refactoring tools, because sometimes it makes a significant mistake. Now, that's often caused by the way I wrote some code and I have to fix it up as part of my refactoring, but I would have discovered that while refactoring manually too, and if I trusted VS I wouldn't have discovered it at all. So VS helps a bit with the typing, but it's not much faster than I'd be without it. A lot of that is probably because I learned to refactor using vim, grep, sed, and other Unix command-line tools, so I have no problem doing large-scale refactoring changes touching thousands of lines over a 100k+ line codebase. Extracting a method is childs play in comparison, and I don't mind the extra few seconds it takes to do it manually exactly the way I want it.
There is definitely a need for better javascript editing tools. VS, with the right plugins, wouldn't be bad, but I'm not sure Intellisense can really cut it. When I'm putting some code into an MVC template or js file and I want to refer to a jQuery plugin I know is loaded by my layout template, there is no way for Intellisense to know about that plugin or its API, so it can't help me. In contrast if I load my app in Firefox and use Firebug's console and debugger, I can type in some code and it's able to show me the API in real-time because it's reflecting the live javascript objects as I type. That's the kind of intellisense I want.
I fully relate, I wish I had the same background, it would have made me probably a better developer, but I'm already hooked...
What I'm wondering is, why can't we have the browser then be our IDE, chrome already supports editing, just need to persist it to my code base
By the way, I strongly suggest using something like resharper, VS is great, but I found eclipse much better if you are looking for those tricks and shortcuts.
If you haven't tried it yet, I encourage anyone to get eclipse, put in some java code, and play with ctrl+1 magic shortcut (mark anything in code and let it do the work for you) it allows you to be more expressive and write code in a modular way, for example, I don't have to be a boolean logic master, or even a smart developer to extract negation up a boolean condition, and if I forgot a param / method, it will create it for me with the right signature, and if I see a piece of string I want to replace with a variable, it takes it for me and adds those dreadful " + ... + " in so I don't have to. does it makes you a zombie programmer? probably yes, does it make you smarter? probably not, but does it make you more productive? absolutely yes.
again, VS I think is nowhere near eclipse JDT in that end (without resharper at least)
I think this is why GWT, Dart, Scala, Hibernate / Seam, Spring all invest so much in eclipse,
most developers of this world (me included) are just not good enough hackers to do it the VIM / grep way... sad but true.
For statically typing Javascript, I strongly recommend Google's Closure toolset- it uses JS comments to statically type and validate your code, plus you can either run it compiled or uncompiled.
but I find it gets in the way a lot... both literally by overlapping the code around the code I'm typing, and figuratively by trying to insert text while I type
I sometimes forget that this is the default, since my first step when installing VS.NET is to turn off all the automatic popping up and getting your way functionality. I think it's analogous to that "Torch Mode" setting that new TVs are on when they're in the showroom, demonstrating every feature they have at once so you see it all and are impressed. The VS.NET that I know doesn't do that. But I guess it would prefer to if you didn't reel it in.
Keep all the good stuff, but leave it behind CTRL+Space. You're four checkboxes away from having your cake and eating it too. And not having it leap up in between you and what you're trying to accomplish.
The author might assume it, but I think it needs to be explicitly stated. Tools like this are often sold as "You don't need to know X because you can now code in Y and translate automatically to X!" That never works out though because there are always leaky abstractions. (For this project, just take a look at the Attributes docs to see how leaky the abstractions are.)
I've had to work with a bunch of C, C++, Java, Perl, and C# developers who were good at backend stuff and just started to learn HTML, CSS, and Javascript, and they're mostly pretty awful at it until they give in and dedicate themselves to the frontend web developer platform and environment. Prior to that they'd grasp at tools like this one that seem to offer hope that they won't have to learn that nasty javascript.
I'm coming at it from a different perspective. I can't worry about what other programmers do. I need tools. I love JS but the tools for it could be better. I'm hoping C#->JS will be a great addition to the toolbox.
