Add Babel Typecheck

[RickWong]

https://github.com/codemix/babel-plugin-typecheck

[ericfong]

Hi, I think is off topic. But

When using "piping" + "babel/register" in my project,
The dev server restart (for about 0.5 to 1 second) after every changes that we make.

I think that is because piping "hot" reloading and babel slow compilation?
Will this make the compilation even slower?

[RickWong]

0.5 to 1 second is considered fast, for restarting node server-side :) "babel/register" allows us to write modern Javascript (ES5/6/7) and Babel Typecheck will allow static + runtime type checking, which prevents an entire class of bugs. So it's worth it. But you can turn it off.

Also, perhaps I should bring back the production build for the server, so Babel-transformations are pre-compiled for production.

[RickWong]

@ericfong Do you think webpack hot-loading for the server (https://github.com/webpack/hot-node-example) would be a faster solution?

[ericfong]

The problem of "piping" + "babel/register":
Step 1: file changed
2: restart
3: compile
4: finally can be used

If webpack way:
Step 1: file changed
2: compile
3: restart after compile (browser HMR is like that, not sure about server)
4: Can be used
Pros: faster?
Cons: stack trace is ... the friend of flux (fuXk)

Personally, I prefer faster.
SourceMap for node?

By the way, I use babel for jsx only. I am using iojs 2.0.
We only use es6 syntax that support natively by iojs.

[RickWong]

I'll have to experiment with server-side HMR. Never done that before. If you have the time, a Pull Request is welcome :)

[RickWong]

On-topic: I added Babel Typecheck plugin. It works quite well for regular functions et cetera but unfortunately doesn't support some ES6 syntax (class methods) yet.