The `enableHooks` feature flag used to only control whether the API
was exposed on the React package. But now it also determines if the
dispatcher and implementation are included in the bundle.
We're using hooks in www, so I've switched the feature flag to `true`
in the www build.
(Alternatively, we could have two feature flags: one for the
implementation and dispatcher, and one for exposing the API on the
React package.)
Removes the `enableDispatchCallback` feature flag and deletes the
associated code. An earlier version of the Hooks proposal included this
feature but we've since decided to remove it.
* [scheduler] Deadline object -> shouldYield
Instead of using a requestIdleCallback-style deadline object, expose a
method Scheduler.shouldYield that returns true if there's a higher
priority event in the queue.
* Nits
* Removed the enableGetDerivedStateFromCatch feature flag (aka permanently enabled the feature)
* Forked/copied ReactErrorBoundaries to ReactLegacyErrorBoundaries for testing componentDidCatch
* Updated error boundaries tests to apply to getDerivedStateFromCatch
* Renamed getDerivedStateFromCatch -> getDerivedStateFromError
* Warn if boundary with only componentDidCatch swallows error
* Fixed a subtle reconciliation bug with render phase error boundary
All of these features are based on features of React's internal
scheduler. The eventual goal is to lift as much as possible out of the
React internals into the Scheduler package.
Includes some renaming of existing methods.
- `scheduleWork` is now `scheduleCallback`
- `cancelScheduledWork` is now `cancelCallback`
Priority levels
---------------
Adds the ability to schedule callbacks at different priority levels.
The current levels are (final names TBD):
- Immediate priority. Fires at the end of the outermost currently
executing (similar to a microtask).
- Interactive priority. Fires within a few hundred milliseconds. This
should only be used to provide quick feedback to the user as a result
of an interaction.
- Normal priority. This is the default. Fires within several seconds.
- "Maybe" priority. Only fires if there's nothing else to do. Used for
prerendering or warming a cache.
The priority is changed using `runWithPriority`:
```js
runWithPriority(InteractivePriority, () => {
scheduleCallback(callback);
});
```
Continuations
-------------
Adds the ability for a callback to yield without losing its place
in the queue, by returning a continuation. The continuation will have
the same expiration as the callback that yielded.
Wrapped callbacks
-----------------
Adds the ability to wrap a callback so that, when it is called, it
receives the priority of the current execution context.
* 🔥 Stop syncing the value attribute on inputs
* Eliminate some additional checks
* Remove initialValue and initialWrapper from wrapperState flow type
* Update tests with new sync logic, reduce some operations
* Update tests, add some caveats for SSR mismatches
* Revert newline change
* Remove unused type
* Call toString to safely type string values
* Add disableInputAttributeSyncing feature flag
Reverts tests to original state, adds attribute sync feature flag,
then moves all affected tests to ReactFire-test.js.
* Revert position of types in toStringValues
* Invert flag on number input blur
* Add clarification why double blur is necessary
* Update ReactFire number cases to be more explicite about blur
* Move comments to reduce diff size
* Add comments to clarify behavior in each branch
* There is no need to assign a different checked behavior in Fire
* Use checked reference
* Format
* Avoid precomputing stringable values
* Revert getToStringValue comment
* Revert placement of undefined in getToStringValue
* Do not eagerly stringify value
* Unify Fire test cases with normal ones
* Revert toString change. Only assign unsynced values when not nully
* Removed 'private' ref methods from UMD forwarding API
* Replaced getters with exported constants since they were no longer referenced for UMD forwarding
* Merged interaction-tracking package into react-scheduler
* Add tracking API to FB+www builds
* Added Rollup plugin to strip no-side-effect imports from Rollup bundles
* Re-bundle tracking and scheduling APIs on SECRET_INTERNALS object for UMD build (and provide lazy forwarding methods)
* Added some additional tests and fixtures
* Fixed broken UMD fixture in master (#13512)
* Removed enableInteractionTrackingObserver as a separate flag; only enableInteractionTracking is used now
* Added interaction-tracking/subscriptions bundle and split tests
* Added multi-subscriber support
* Moved subscriptions behind feature flag
* Fixed bug with wrap() parameters and added test
* Replaced wrap arrow function
* Remove rAF fork
**what is the change?:**
Undid https://github.com/facebook/react/pull/12837
**why make this change?:**
We originally forked rAF because we needed to pull in a particular
version of rAF internally at Facebook, to avoid grabbing the default
polyfilled version.
The longer term solution, until we can get rid of the global polyfill
behavior, is to initialize 'schedule' before the polyfilling happens.
Now that we have landed and synced
https://github.com/facebook/react/pull/12900 successfully, we can
initialize 'schedule' before the polyfill runs.
So we can remove the rAF fork. Here is how it will work:
1. Land this PR on Github.
2. Flarnie will quickly run a sync getting this change into www.
3. We delete the internal forked version of
'requestAnimationFrameForReact'.
4. We require 'schedule' in the polyfill file itself, before the
polyfilling happens.
**test plan:**
Flarnie will manually try the above steps locally and verify that things
work.
**issue:**
Internal task T29442940
* fix nits
* fix tests, fix changes from rebasing
* fix lint
* 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
* add legacy context APIs warning in strict mode
* refactor if statement and the warning message
* add other flags for type check
* add component stack tree and refactor wording
* fix the nits
* Extract base Jest config
This makes it easier to change the source config without affecting the build test config.
* Statically import the host config
This changes react-reconciler to import HostConfig instead of getting it through a function argument.
Rather than start with packages like ReactDOM that want to inline it, I started with React Noop and ensured that *custom* renderers using react-reconciler package still work. To do this, I'm making HostConfig module in the reconciler look at a global variable by default (which, in case of the react-reconciler npm package, ends up being the host config argument in the top-level scope).
This is still very broken.
* Add scaffolding for importing an inlined renderer
* Fix the build
* ES exports for renderer methods
* ES modules for host configs
* Remove closures from the reconciler
* Check each renderer's config with Flow
* Fix uncovered Flow issue
We know nextHydratableInstance doesn't get mutated inside this function, but Flow doesn't so it thinks it may be null.
Help Flow.
* Prettier
* Get rid of enable*Reconciler flags
They are not as useful anymore because for almost all cases (except third party renderers) we *know* whether it supports mutation or persistence.
This refactoring means react-reconciler and react-reconciler/persistent third-party packages now ship the same thing.
Not ideal, but this seems worth how simpler the code becomes. We can later look into addressing it by having a single toggle instead.
* Prettier again
* Fix Flow config creation issue
* Fix imprecise Flow typing
* Revert accidental changes
* 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
* Timeout component
Adds Timeout component. If a promise is thrown from inside a Timeout component,
React will suspend the in-progress render from committing. When the promise
resolves, React will retry. If the render is suspended for longer than the
maximum threshold, the Timeout switches to a placeholder state.
The timeout threshold is defined as the minimum of:
- The expiration time of the current render
- The `ms` prop given to each Timeout component in the ancestor path of the
thrown promise.
* Add a test for nested fallbacks
Co-authored-by: Andrew Clark <acdlite@fb.com>
* Resume on promise rejection
React should resume rendering regardless of whether it resolves
or rejects.
* Wrap Suspense code in feature flag
* Children of a Timeout must be strict mode compatible
Async is not required for Suspense, but strict mode is.
* Simplify list of pending work
Some of this was added with "soft expiration" in mind, but now with our revised
model for how soft expiration will work, this isn't necessary.
It would be nice to remove more of this, but I think the list itself is inherent
because we need a way to track the start times, for <Timeout ms={ms} />.
* Only use the Timeout update queue to store promises, not for state
It already worked this way in practice.
* Wrap more Suspense-only paths in the feature flag
* Attach promise listener immediately on suspend
Instead of waiting for commit phase.
* Infer approximate start time using expiration time
* Remove list of pending priority levels
We can replicate almost all the functionality by tracking just five
separate levels: the highest/lowest priority pending levels, the
highest/lowest priority suspended levels, and the lowest pinged level.
We lose a bit of granularity, in that if there are multiple levels of
pending updates, only the first and last ones are known. But in practice
this likely isn't a big deal.
These heuristics are almost entirely isolated to a single module and
can be adjusted later, without API changes, if necessary.
Non-IO-bound work is not affected at all.
* ReactFiberPendingWork -> ReactFiberPendingPriority
* Renaming method names from "pending work" to "pending priority"
* Get rid of SuspenseThenable module
Idk why I thought this was neccessary
* Nits based on Sebastian's feedback
* More naming nits + comments
* Add test for hiding a suspended tree to unblock
* Revert change to expiration time rounding
This means you have to account for the start time approximation
heuristic when writing Suspense tests, but that's going to be
true regardless.
When updating the tests, I also made a fix related to offscreen
priority. We should never timeout inside a hidden tree.
* palceholder -> placeholder
Add a new component type, Profiler, that can be used to collect new render time metrics. Since this is a new, experimental API, it will be exported as React.unstable_Profiler initially.
Most of the functionality for this component has been added behind a feature flag, enableProfileModeMetrics. When the feature flag is disabled, the component will just render its children with no additional behavior. When the flag is enabled, React will also collect timing information and pass it to the onRender function (as described below).
* Support using id to cancel scheduled callback
**what is the change?:**
see title
**why make this change?:**
Once we support multiple callbacks you will need to use the id to
specify which callback you mean.
**test plan:**
Added a test, ran all tests, lint, etc.
* ran prettier
* fix lint
* Use object for storing callback info in scheduler
* Wrap initial test in a describe block
* Support multiple callbacks in `ReactScheduler`
**what is the change?:**
We keep a queue of callbacks instead of just one at a time, and call
them in order first by their timeoutTime and then by the order which
they were scheduled in.
**why make this change?:**
We plan on using this module to coordinate JS outside of React, so we
will need to schedule more than one callback at a time.
**test plan:**
Added a boatload of shiny new tests. :)
Plus ran all the old ones.
NOTE: The tests do not yet cover the vital logic of callbacks timing
out, and later commits will add the missing test coverage.
* Heuristic to avoid looking for timed out callbacks when none timed out
**what is the change?:**
Tracks the current soonest timeOut time for all scheduled callbacks.
**why make this change?:**
We were checking every scheduled callback to see if it timed out on
every tick. It's more efficient to skip that O(n) check if we know that
none have timed out.
**test plan:**
Ran existing tests.
Will write new tests to cover timeout behavior in more detail soon.
* Put multiple callback support under a disabled feature flag
**what is the change?:**
See title
**why make this change?:**
We don't have error handling in place yet, so should maintain the old
behavior until that is in place.
But want to get this far to continue making incremental changes.
**test plan:**
Updated and ran tests.
* Hide support for multiple callbacks under a feature flag
**what is the change?:**
see title
**why make this change?:**
We haven't added error handling yet, so should not expose this feature.
**test plan:**
Ran all tests, temporarily split out the tests for multiple callbacks
into separate file. Will recombine once we remove the flag.
* Fix nits from code review
See comments on https://github.com/facebook/react/pull/12743
* update checklist in comments
* Remove nested loop which calls additional timed out callbacks
**what is the change?:**
We used to re-run any callbacks which time out whilst other callbacks
are running, but now we will only check once for timed out callbacks
then then run them.
**why make this change?:**
To simplify the code and the behavior of this module.
**test plan:**
Ran all existing tests.
* Remove feature flag
**what is the change?:**
see title
**why make this change?:**
Because only React is using this, and it sounds like async. rendering
won't hit any different behavior due to these changes.
**test plan:**
Existing tests pass, and this allowed us to recombine all tests to run
in both 'test' and 'test-build' modes.
* remove outdated file
* fix typo
* Remove the 'alwaysUseRequestIdleCallbackPolyfill' feature flag
**what is the change?:**
Removes the feature flag 'alwaysUseRequestIdleCallbackPolyfill', such
that we **always** use the polyfill for requestIdleCallback.
**why make this change?:**
We have been testing this feature flag at 100% for some time internally,
and determined it works better for React than the native implementation.
Looks like RN was overriding the flag to use the native when possible,
but since no RN products are using 'async' mode it should be safe to
switch this flag over for RN as well.
**test plan:**
We have already been testing this internally for some time.
**issue:**
internal task t28128480
* fix mistaken conditional
* Add mocking of rAF, postMessage, and initial test for ReactScheduler
**what is the change?:**
- In all tests where we previously mocked rIC or relied on native
mocking which no longer works, we are now mocking rAF and postMessage.
- Also adds a basic initial test for ReactScheduler.
NOTE -> we do plan to write headless browser tests for ReactScheduler!
This is just an initial test, to verify that it works with the mocked
out browser APIs as expected.
**why make this change?:**
We need to mock out the browser APIs more completely for the new
'ReactScheduler' to work in our tests. Many tests are depending on it,
since it's used at a low level.
By mocking the browser APIs rather than the 'react-scheduler' module, we
enable testing the production bundles. This approach is trading
isolation for accuracy. These tests will be closer to a real use.
**test plan:**
run the tests :)
**issue:**
internal task T28128480
* Added new "native-fb" and "native-fabric-fb" bundles.
* Split RN_DEV and RN_PROD bundle types into RN_OSS_DEV, RN_OSS_PROD, RN_FB_DEV, and RN_FB_PROD. (This is a bit redundant but it seemed the least intrusive way of supporting a forked feature flags file for these bundles.)
* Renamed FB_DEV and FB_PROD bundle types to be more explicitly for www (FB_WWW_DEV and FB_WWW_PROD)
* Removed Haste @providesModule headers from the RB-specific RN renderer bundles to avoid a duplicate name conflicts.
* Remove dynamic values from OSS RN feature flags. (Leave them in FB RN feature flags.)
* Updated the sync script(s) to account for new renderer type.
* Move ReactFeatureFlags.js shim to FB bundle only (since OSS bundle no longer needs dynamic values).
These are based on the ReactNoop renderer, which we use to test React
itself. This gives library authors (Relay, Apollo, Redux, et al.) a way
to test their components for async compatibility.
- Pass `unstable_isAsync` to `TestRenderer.create` to create an async
renderer instance. This causes updates to be lazily flushed.
- `renderer.unstable_yield` tells React to yield execution after the
currently rendering component.
- `renderer.unstable_flushAll` flushes all pending async work, and
returns an array of yielded values.
- `renderer.unstable_flushThrough` receives an array of expected values,
begins rendering, and stops once those values have been yielded. It
returns the array of values that are actually yielded. The user should
assert that they are equal.
Although we've used this pattern successfully in our own tests, I'm not
sure if these are the final APIs we'll make public.
We'll use this in www to test whether the polyfill is better at
scheduling high-pri async work than the native one. My preliminary tests
suggest "yes" but it's hard to say for certain, given how difficult it
is to consistently reproduce the starvation issues we've been seeing.
* Add stack unwinding phase for handling errors
A rewrite of error handling, with semantics that more closely match
stack unwinding.
Errors that are thrown during the render phase unwind to the nearest
error boundary, like before. But rather than synchronously unmount the
children before retrying, we restart the failed subtree within the same
render phase. The failed children are still unmounted (as if all their
keys changed) but without an extra commit.
Commit phase errors are different. They work by scheduling an error on
the update queue of the error boundary. When we enter the render phase,
the error is popped off the queue. The rest of the algorithm is
the same.
This approach is designed to work for throwing non-errors, too, though
that feature is not implemented yet.
* Add experimental getDerivedStateFromCatch lifecycle
Fires during the render phase, so you can recover from an error within the same
pass. This aligns error boundaries more closely with try-catch semantics.
Let's keep this behind a feature flag until a future release. For now, the
recommendation is to keep using componentDidCatch. Eventually, the advice will
be to use getDerivedStateFromCatch for handling errors and componentDidCatch
only for logging.
* Reconcile twice to remount failed children, instead of using a boolean
* Handle effect immediately after its thrown
This way we don't have to store the thrown values on the effect list.
* ReactFiberIncompleteWork -> ReactFiberUnwindWork
* Remove startTime
* Remove TypeOfException
We don't need it yet. We'll reconsider once we add another exception type.
* Move replay to outer catch block
This moves it out of the hot path.
Andrew Clark
Andrew Clark
Brian Vaughn
Dan Abramov
Andrew Clark
Nathan Hunzaker
Héctor Ramos
Alex Taylor
Chang Yan
Flarnie Marchan