**what is the change?:**
Basically undoes 4b2e65d32e (diff-904ceabd8a1e9a07ab1d876d843d62e1)
**why make this change?:**
We rolled out this fix internally and in open source weeks ago, and now
we're cleaning up.
**test plan:**
Ran tests and lint, and really we have been testing this because the
flag is open internally as of last week or so.
**issue:**
Internal task T29948812 has some info.
* 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
* 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).
* 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).
Brian Vaughn