[TheAnimus]

Full discolusre, I'm dyslexic. I've spent DAYS working on bugs that were typos that I just couldn't notice. This may well make me rather biased.

However I strongly disagree with this, TypeScript isn't ment to 'Fix' JavaScript, as any valid JS is valid TS. This limits a lot.

What it does do, is reduce boiler plate, give you a take as much as you want level of typing. No features are missing, you can always just <any> and do what you want.

The 'flaw' that the Type Defintions for a library might change, and be out of date, is a also a massive con. Want to see if I've any simple type missing or changed errors introduced by an otherwise innocuous library change? Easy! Granted, it's no replacement for integration testing, to ensure functions still behave as expected.

The comment about the 'this' issue that plagues the functional mascarading as a class nature of JS, is incomplete. It is simple to fix in TS, using the Lambda notation.

[johnny_reilly]

Good points. I also noticed the 'this' issue Jeff had and ended up turning it into a blogpost as I don't think the instance methods / lambda notation approach is as well known as I'd hope. It's here if you're interested:

http://icanmakethiswork.blogspot.co.uk/2014/04/typescript-in...