[Node 4] Prepare for Node 4

[ide]

I believe the codebase is in good shape for Node 4.0. It's going to be much better when we can tell people just to get the latest version of Node without any of the io.js confusion.

Things that need to be done:

• Update the documentation to tell people to install Node.js 4 or newer ([Docs] Update RN website docs to mention Node 4+ instead of io.js #2546)
• Update the version check message in the packager ([Node 4.x] Update the packager's version check message for Node 4.0 #2547)
• Test with Node 4.0 RC. Some of the native modules like the WebSockets library may break since V8 is probably being upgraded from 4.4 to 4.5 but I expect we're OK since NAN is designed to protect against this.
• Upgrade the Travis CI tests to run against Node 4.0 ([Node 4] Update .travis.yml to install Node 4.x #2548)
• Fix jest, which breaks when mocking bound functions (Bound functions in Node 4.0 break moduleMocker.js jestjs/jest#488)

cc @vjeux and @cpojer I think you will be excited

[cpojer]

• Does it have arrow functions like Chrome 45?
• Where can I find the RC?

[ide]

The RC is potentially getting cut later today. If the V8 4.5 upgrade lands in time, then I believe it includes arrow functions (that aren't broken and behind a flag like in 3.x).

[cpojer]

They are now shipped natively in Chrome, and they are awesome.

[vjeux]

Me gusta

[ide]

Some good news: react-native installs fine with 4.0.0-rc.1. The packager, Chrome debugger, and React devtools all work with the UIExplorer. All of the jest tests pass except this one:

 FAIL  Libraries/Utilities/__tests__/MessageQueue-test.js
SyntaxError: react-native/Libraries/Utilities/__tests__/MessageQueue-test.js: react-native/Libraries/Utilities/MessageQueue.js: react-native/Libraries/JavaScriptAppEngine/System/JSTimers/JSTimersExecution.js: Unexpected identifier
  at Function (native)
  at makeComponent (react-native/node_modules/jest-cli/src/lib/moduleMocker.js:157:15)
  at generateMock (react-native/node_modules/jest-cli/src/lib/moduleMocker.js:222:16)
  at Object.generateFromMetadata (react-native/node_modules/jest-cli/src/lib/moduleMocker.js:255:14)

jest bug opened here: jestjs/jest#488. react-native tests pass with jestjs/jest#489.

[cpojer]

👍 I have a reasonably important bug to fix for jest, I'll do that on Tuesday and tag 0.5.2.

[ide]

All tests are green! https://travis-ci.org/facebook/react-native/builds/79353110

@vjeux could you find someone to look at #2548 (upgrade jest + travis), #2547 (add message to the packager), and #2546 (update docs) in that order? Once #2548 is in, we can also cherry-pick 7f65971 over to 0.11-stable and ship Node 4.x support with 0.11 and not think about "io.js" any more.

EDIT: I went ahead with cherry-picking 7f65971

[brentvatne]

@ide 😍

[alinz]

👍

[cyprusglobe]

👍

[brunoksato]

+1

[chirag04]

Seems like everything is in place for node 4 now.