Jest 15 has just been released and is way more awesome: http://facebook.github.io/jest/blog/2016/09/01/jest-15.html
This pull request updates jest from version 12 to 15. Right now there's a fix in jest around Symbol that hasn't been released yet, so this will break CI and cannot be merged it. But once it ships by the end of the day, we'll be good to go :)
See comments inline for all the changes I've done.
We currently write all our tests against the DOM implementation.
I need a way to run the Fiber tests against it. But I don't want
to take on any package dependencies on Fiber modules yet.
There's a problem with jest right now where you can't globally
mock modules that already exist. So I have to add a global call
to jest.mock.
Luckily we already have a way to test the useCreateElement paths
using a feature flag. I won't activate this flag in travis until
it passes, but the idea is to run all three variants in travis.
I'm not sure that invoking rAF and rIC synchronously is the best
way to test this since it doesn't capture the backwards
compatibility aspect. I.e. the fact that people might be relying
on the synchronous nature in real apps too. It's a start.
Ideally, jest would have these built-in.
Test Plan: Changed the preprocessor to log the output of babel.transform and saw
```
var _jsxFileName = 'src/isomorphic/modern/element/__tests__/ReactJSXElementValidator-test.js';
```
in the resulting output, instead of an absolute path.
You could make the argument that this should be optional, but it doesn't
work without it so we might as well just enforce it.
Makes `jest` work by default.
Turns out jest is _incredibly_ slow at resolving require paths like `require('fbjs/lib/foo')`. Like several milliseconds per require. Really adds up when all our files require `invariant` and `warning`. Here's a temporary hack to make things fast again.
Test Plan:
```
npm test src/renderers/shared/reconciler/__tests__/ReactCompositeComponent-test.js
```
has a self-proclaimed runtime of ~8 seconds now instead of ~35 seconds.
This reworks a few things in building and distributing React. The biggest change is using fbjs to share dependencies with other libraries. We're also using Gulp for some build steps.
