* Fix react-dom ReferenceError requestAnimationFrame in non-browser env (#13000)
The https://github.com/facebook/react/pull/12931 ( https://github.com/facebook/react/commit/79a740c6e32ca300d4e7ff55ab06de172d4237fd ) broke the server-side rendering: in the `fixtures/ssr` the following error appeared from the server-side when `localhost:3000` is requested:
```
ReferenceError: requestAnimationFrame is not defined
at /__CENSORED__/react/build/node_modules/react-dom/cjs/react-dom.development.js:5232:34
at Object.<anonymous> (/__CENSORED__/react/build/node_modules/react-dom/cjs/react-dom.development.js:17632:5)
at Module._compile (module.js:624:30)
at Module._extensions..js (module.js:635:10)
at Object.require.extensions.(anonymous function) [as .js] (/__CENSORED__/react/fixtures/ssr/node_modules/babel-register/lib/node.js:152:7)
at Module.load (module.js:545:32)
at tryModuleLoad (module.js:508:12)
at Function.Module._load (module.js:500:3)
at Module.require (module.js:568:17)
at require (internal/module.js:11:18)
```
The exception pointed to this line:
```js
// We capture a local reference to any global, in case it gets polyfilled after
// this module is initially evaluated.
// We want to be using a consistent implementation.
const localRequestAnimationFrame = requestAnimationFrame;
```
**Test plan**
1. In `react` repo root, `yarn && yarn build`.
2. In `fixtures/ssr`, `yarn && yarn start`,
3. In browser, go to `http://localhost:3000`.
4. Observe the fixture page, not the exception message.
* Move the requestAnimationFrameForReact check and warning to callsites (#13000)
According to the comment by @gaearon: https://github.com/facebook/react/pull/13001#issuecomment-395803076
* Use `invariant` instead of `throw new Error`, use the same message (#13000)
According to the comment by @gaearon: https://github.com/facebook/react/pull/13001#discussion_r194133355
**what is the change?:**
In a recent PR we were referencing some global variables and storing
local references to them.
To make things more natural, we co-opted the original name of the global
for our local reference. To make this work with Flow, we get the
original reference from 'window.requestAnimationFrame' and assign it to
'const requestAnimationFrame'.
Sometimes React is used in an environment where 'window' is not defined
- in that case we need to use something else, or hide the 'window'
reference somewhere.
We opted to use 'global' thinking that Babel transforms would fill that
in with the proper thing.
But for some of our fixtures we are not doing that transform on the
bundle.
**why make this change?:**
I want to unbreak this on master and then investigate more about what we
should do to fix this.
**test plan:**
run `yarn build` and open the fixtures.
**issue:**
https://github.com/facebook/react/issues/12930
* Use local references to global things inside 'scheduler'
**what is the change?:**
See title
**why make this change?:**
We want to avoid initially calling one version of an API and then later
accessing a polyfilled version.
**test plan:**
Run existing tests.
* Shim ReactScheduler for www
**what is the change?:**
In 'www' we want to reference the separate build of ReactScheduler,
which allows treating it as a separate module internally.
**why make this change?:**
We need to require the ReactScheduler before our rAF polyfill activates,
in order to customize which custom behaviors we want.
This is also a step towards being able to experiment with using it
outside of React.
**test plan:**
Ran tests, ran the build, and ran `test-build`.
* Generate a bundle for fb-www
**what is the change?:**
See title
**why make this change?:**
Splitting out the 'schedule' module allows us to load it before
polyfills kick in for rAF and other APIs.
And long term we want to split this into a separate module anyway, this
is a step towards that.
**test plan:**
I'll run the sync next week and verify that this all works. :)
* ran prettier
* fix rebase issues
* Change names of variables used for holding globals
* Temporary fix for grabbing wrong rAF polyfill in ReactScheduler
**what is the change?:**
For now...
We need to grab a slightly different implementation of rAF internally at
FB than in Open Source. Making rAF a dependency of the ReactScheduler
module allows us to fork the dependency at FB.
NOTE: After this lands we have an alternative plan to make this module
separate from React and require it before our Facebook timer polyfills
are applied. But want to land this now to keep master in a working state
and fix bugs folks are seeing at Facebook.
Thanks @sebmarkbage @acdlite and @sophiebits for discussing the options
and trade-offs for solving this issue.
**why make this change?:**
This fixes a problem we're running into when experimenting with
ReactScheduler internally at Facebook, **and* it's part of our long term
plan to use dependency injection with the scheduler to make it easier to
test and adjust.
**test plan:**
Ran tests, lint, flow, and will manually test when syncing into
Facebook's codebase.
**issue:**
See internal task T29442940
* ran prettier
Ivan Babak
Flarnie Marchan