Provides partial support for React.lazy() components from the existing PartialRenderer server-side renderer.
Lazy components which are already resolved (or rejected), perhaps with something like `react-ssr-prepass`, can be continued into synchronously. If they have not yet been initialized, they'll be initialized before checking, opening the possibility to exploit this capability with a babel transform. If they're pending (which will typically be the case for a just initialized async ctor) then the existing invariant continues to be thrown.
* Move dehydrated to be child of regular SuspenseComponent
We now store the comment node on SuspenseState instead and that indicates
that this SuspenseComponent is still dehydrated.
We also store a child but that is only used to represent the DOM node for
deletions and getNextHostSibling.
* Move logic from DehydratedSuspenseComponent to SuspenseComponent
Forked based on SuspenseState.dehydrated instead.
* Retry logic for dehydrated boundary
We can now simplify the logic for retrying dehydrated boundaries without
hydrating. This is becomes simply a reconciliation against the dehydrated
fragment which gets deleted, and the new children gets inserted.
* Remove dehydrated from throw
Instead we use the regular Suspense path. To save code, we attach retry
listeners in the commit phase even though technically we don't have to.
* Pop to nearest Suspense
I think this is right...?
* Popping hydration state should skip past the dehydrated instance
* Split mount from update and special case suspended second pass
The DidCapture flag isn't used consistently in the same way. We need
further refactor for this.
* Reorganize update path
If we remove the dehydration status in the first pass and then do a second
pass because we suspended, then we need to continue as if it didn't
previously suspend. Since there is no fragment child etc.
However, we must readd the deletion.
* Schedule context work on the boundary and not the child
* Warn for Suspense hydration in legacy mode
It does a two pass render that client renders the content.
* Rename DehydratedSuspenseComponent -> DehydratedFragment
This now doesn't represent a suspense boundary itself. Its parent does.
This Fiber represents the fragment around the dehydrated content.
* Refactor returns
Avoids the temporary mutable variables. I kept losing track of them.
* Add a comment explaining the type.
Placing it in the type since that's the central point as opposed to spread
out.
When React schedules a rendering task, it passes a `timeout` option
based on its expiration time. This is intended to avoid starvation
by other React updates. However, it also affects the relative priority
of React tasks and other Scheduler tasks at the same level, like
data processing.
This adds a feature flag to disable passing a `timeout` option to
Scheduler. React tasks will always append themselves to the end of
the queue, without jumping ahead of already scheduled tasks.
This does not affect the order in which React updates within a single
root are processed, but it could affect updates across multiple roots.
This also doesn't remove the expiration from Scheduler. It only means
that React tasks are not given special treatment.
* Add a feature flag to disable legacy context
* Address review
- invariant -> warning
- Make this.context and context argument actually undefined
* Increase test coverage for lifecycles
* Also disable it on the server is flag is on
* Make this.context {} when disabled, but function context is undefined
* Move checks inside
In this PR, for tests (specifically, code inside an `act()` scope), we immediately trigger work that would have otherwise required a timeout. This makes it simpler to tests loading/spinner states, and makes tests resilient to changes in React.
For some of our tests(specifically, ReactSuspenseWithNoopRenderer-test.internal), we _don't_ want fallbacks to immediately trigger, because we're testing intermediate states and such. Added a feature flag `flushSuspenseFallbacksInTests` to disable this behaviour on a per case basis.
Concurrent/Batched mode tests should always be run with a mocked scheduler (v17 or not). This PR adds a warning for the same. I'll put up a separate PR to the docs with a page detailing how to mock the scheduler.
This adds a 'SuspenseCallback' feature flag. When the property is set on
a suspense component it will be called during the commit phase with a
set of the immediate thenable for this component. This will allow user
code to build runtime tracing of the cause for a suspense boundary.
- redoes #15431 from scratch, taking on the feedback there
- unifies the messaging between "deprecated" and UNSAFE_ lifecycle messages. It reorganizes ReactStrictModeWarnings.js to capture and flush all the lifecycle warnings in one procedure each.
- matches the warning from ReactPartialRenderer to match the above change
- passes all the tests
- this also turns on `warnAboutDeprecatedLifecycles` for the test renderer. I think we missed doing so it previously. In a future PR, I'll remove the feature flag altogether.
- this DOES NOT do the same treatment for context warnings, I'll do that in another PR too
* [Scheduler] requestPaint
Signals to Scheduler that the browser needs to paint the screen. React
will call it in the commit phase. Scheduler will yield at the end of
the current frame, even if there is no pending input.
When `isInputPending` is not available, this has no effect, because we
yield at the end of every frame regardless.
React will call `requestPaint` in the commit phase as long as there's at
least one effect. We could choose not to call it if none of the effects
are DOM mutations, but this is so rare that it doesn't seem worthwhile
to bother checking.
* Fall back gracefully if requestPaint is missing
* Add SuspenseList component type
* Push SuspenseContext for SuspenseList
* Force Suspense boundaries into their fallback state
In the "together" mode, we do a second render pass that forces the
fallbacks to stay in place, if not all can unsuspend at once.
* Add test
* Transfer thennables to the SuspenseList
This way, we end up retrying the SuspenseList in case the nested boundary
that just suspended doesn't actually get mounted with this set of
thennables. This happens when the second pass renders the fallback
directly without first attempting to render the content.
* Add warning for unsupported displayOrder
* Add tests for nested sibling boundaries and nested lists
* Fix nested SuspenseList forwarding thennables
* Rename displayOrder to revealOrder
Display order has some "display list" connotations making it sound like
a z-index thing.
Reveal indicates that this isn't really about when something gets rendered
or is ready to be rendered. It's about when content that is already there
gets to be revealed.
* Add test for avoided boundaries
* Make SuspenseList a noop in legacy mode
* Use an explicit suspense list state object
This will be used for more things in the directional case.
* Same as previous commit, but for Flare
I don't know what the public API for setting the event priority should
be. Right now it accepts a numeric enum, but is this what we want?
Maybe it should be a string enum? I've punted on this for now.
* Add test for hover events
* [Events] Add EventPriority enum
React DOM's DispatchConfig for synthetic events has an `isDiscrete`
field that affects how updates triggered by an event are scheduled.
Events are either discrete or continuous.
This commit adds an additional type of configuration where an event
has user-blocking priority, but is not discrete. E.g. updates triggered
by hover are more important than the default, but they don't need to
be processed serially. Because there are now three types of event
priority instead of two, I've replaced the `isDiscrete` boolean with an
enum: `eventPriority`.
This commit implements the new enum value but does not change any
behavior. I'll enable it behind a feature flag in the next commit.
I've only implemented this in the legacy event system. I'll leave Flare
for a follow-up.
* enableUserBlockingEvents feature flag
Adds a feature flag to increase the priority of events like `mouseover`,
without making them discrete.
This commit is a follow-up to https://github.com/facebook/react/pull/15604, which explains more of the rationale behind moving React Native to path-based imports and the work needed in the React repository. In that linked PR, the generated renderers were updated but not the shims; this commit updates the shims.
The problem is that FB needs a different copy of the built renderers than the OSS versions so we need a way for FB code to import different modules than in OSS. This was previously done with Haste, but with the removal of Haste from RN, we need another mechanism. Talking with cpojer, we are using a `.fb.js` extension that Metro can be configured to prioritize over `.js`.
This commit generates FB's renderers with the `.fb.js` extension and OSS renderers with just `.js`. This way, FB can internally configure Metro to use the `.fb.js` implementations and OSS will use the `.js` ones, letting us swap out which implementation gets bundled.
Test Plan: Generated the renderers and shims with `yarn build` and then verified that the generated shims don't contain any Haste-style imports. Copied the renderers and shims into RN manually and launched the RNTester app to verify it loads end-to-end. Added `.fb.js` to the extensions in `metro.config.js` and verified that the FB-specific bundles loaded.
* Add suspendIfNeeded API and a global scope to track it
Adds a "current" suspense config that gets applied to all updates scheduled
during the current scope.
I suspect we might want to add other types of configurations to the "batch"
so I called it the "batch config".
This works across renderers/roots but they won't actually necessarily go
into the same batch.
* Add the suspenseConfig to all updates created during this scope
* Compute expiration time based on the timeout of the suspense config
* Track if there was a processed suspenseConfig this render pass
We'll use this info to suspend a commit for longer when necessary.
* Mark suspended states that should be avoided as a separate flag
This lets us track which renders we want to suspend for a short time vs
a longer time if possible.
* Suspend until the full expiration time if something asked to suspend
* Reenable an old test that we can now repro again
* Suspend the commit even if it is complete if there is a minimum delay
This can be used to implement spinners that don't flicker if the data
and rendering is really fast.
* Default timeoutMs to low pri expiration if not provided
This is a required argument in the type signature but people may not
supply it and this is a user facing object.
* Rename to withSuspenseConfig and drop the default config
This allow opting out of suspending in some nested scope.
A lot of time when you use this function you'll use it with high level
helpers. Those helpers often want to accept some additional configuration
for suspense and if it should suspend at all. The easiest way is to just
have the api accept null or a suspense config and pass it through. However,
then you have to remember that calling suspendIfNeeded has a default.
It gets simpler by just saying tat you can pass the config. You can have
your own default in user space.
* Track the largest suspense config expiration separately
This ensures that if we've scheduled lower pri work that doesn't have a
suspenseConfig, we don't consider its expiration as the timeout.
* Add basic tests for functionality using each update mechanism
* Fix issue when newly created avoided boundary doesn't suspend with delay
* Add test for loading indicator with minLoadingDurationMs option
