Transpile on build

[grabbou]

React Native supports Node >= 4, according to its package.json:

  "engines": {
    "node": ">=4"
  },

We are running latest Node which makes it possible to use ES2015+ features w/o transpiling first. We need a build step that will compile code to Node 4.x (there's preset somewhere I believe).

In dev mode, let's call CLI via cli/index.js which contains requireHook. Production builds should use cli/cli which doesn't have it.

This is done for speed (see how slow is current CLI)

[grabbou]

FYI @zamotany I have updated the description and title of this issue so it's easier to start.

[zamotany]

In dev mode, let's call CLI via cli/index.js which contains requireHook. Production builds should use cli/cli which doesn't have it.

Are you sure that's possible?? From what I know there is no option to specify witch binary to use depending on environment. I suggest to have single binary entry and there decide whether to use dev CLI or production CLI.

[grabbou]

Are you sure that's possible?

Yeah, in dev mode you'd call it via node whereas binary would skip the require hook.

Anyway, recent discussion moved us towards direction that uses babel-env with node: current meaning we won't transpile anything but flowtypes on latest Node version.

Having said so, this can be closed for now.