I like everything you propose here. Dart is earlier in development than I think most people realize, and I really hope we can get to something like what you're listing. Definitely self-hosting and a self-hosted IDE would be on my love-to-have list. As a testing nerd, integrating testing would definitely be on it too.
A good development environment is something where you could really differentiate yourselves, and I guess you could very easily integrate introspection and analysis features into chrome to help with it.
I've been thinking for years that if I ever were to develop a new language, I would start from developer usability first - I think there is much more to innovate there than in the core language features, nowadays. Developer usability is tightly coupled with the development tools the developer can use, not just with abstract language features. And especially for web development, you can't think only about top of class developers.
As I'm at it, I'll write here my dream feature of any language and IDE - not knowing if it is really feasible, but it doesn't look really impossible to me. Use case:
- You run your unit tests
- An assertion fails/there is an error
- A debugger brings you to where the problem is
- You can step back from where you are, make changes on the fly to your code and the tests, and step forward to the assertion/error again.
I guess that with a VM, and excluding some operations that depend from external status and which are destructive, this could be possible, and it could allow an incredible speedup in development...
- write a test for a method that isn't there yet
- run it, get a red bar, as expected
- run it in debug mode, and get a debugger
- write the method implementation in the debugger
- possibly write other methods that the new method calls, also in the debugger
- resume the program, get a green bar
Writing code in the debugger is great, because you've got all the runtime state right in front of you, and you can step through the code you're working on. I'd love, love, love to see this in Dart.
I read about this, and even tried downloading squeak once, but didn't find it very compelling. I admit that I might not have given it the time it needed, though...
