The following APIs have been added to the `react` stable entry point:
* `SuspenseList`
* `startTransition`
* `unstable_createMutableSource`
* `unstable_useMutableSource`
* `useDeferredValue`
* `useTransition`
The following APIs have been added or removed from the `react-dom` stable entry point:
* `createRoot`
* `unstable_createPortal` (removed)
The following APIs have been added to the `react-is` stable entry point:
* `SuspenseList`
* `isSuspenseList`
The following feature flags have been changed from experimental to true:
* `enableLazyElements`
* `enableSelectiveHydration`
* `enableSuspenseServerRenderer`
We added this unstable feature a few years ago, as a way to opt out of
context updates, but it didn't prove useful in practice.
We have other proposals for how to address the same problem, like
context selectors.
Since it was prefixed with `unstable_`, we should be able to remove it
without consequence. The hook API already warned if you used it.
Even if someone is using it somewhere, it's meant to be an optimization
only, so if they are using the API properly, it should not have any
semantic impact.
* Fix native event batching in concurrent mode
* Wrap DevTools test updates with act
These tests expect the `scheduleUpdate` DevTools hook to trigger a
synchronous re-render with legacy semantics, but flushing in a microtask
is fine. Wrapping the updates with `act` fixes it.
* Testing nits
* Nit: Check executionContext === NoContext first
In the common case it will be false and the binary expression will
short circuit.
Co-authored-by: Andrew Clark <git@andrewclark.io>
* Remove react/unstable_cache
We're probably going to make it available via the dispatcher. Let's remove this for now.
* Add readContext() to the dispatcher
On the server, it will be per-request.
On the client, there will be some way to shadow it.
For now, I provide it on the server, and throw on the client.
* Use readContext() from react-fetch
This makes it work on the server (but not on the client until we implement it there.)
Updated the test to use Server Components. Now it passes.
* Fixture: Add fetch from a Server Component
* readCache -> getCacheForType<T>
* Add React.unstable_getCacheForType
* Add a feature flag
* Fix Flow
* Add react-suspense-test-utils and port tests
* Remove extra Map lookup
* Unroll async/await because build system
* Add some error coverage and retry
* Add unstable_getCacheForType to Flight entry
* Remove Blocks
* Remove Flight Server Runtime
There's no need for this now that the JSResource is part of the bundler
protocol. Might need something for Webpack plugin specifically later.
* Devtools
* update all facebook.github.io links
* facebookincubator links : update some outdated links and fix two other broken links where they are actually the latest updated ones
In the next major release, we intend to drop support for using the `act`
testing helper in production. (It already fires a warning.) The
rationale is that, in order for `act` to work, you must either mock the
testing environment or add extra logic at runtime. Mocking the testing
environment isn't ideal because it requires extra set up for the user.
Extra logic at runtime is fine only in development mode — we don't want
to slow down the production builds.
Since most people only run their tests in development mode, dropping
support for production should be fine; if there's demand, we can add it
back later using a special testing build that is identical to the
production build except for the additional testing logic.
One blocker for removing production support is that we currently use
`act` to test React itself. We must test React in both development and
production modes.
So, the solution is to fork `act` into separate public and
internal implementations:
- *public implementation of `act`* – exposed to users, only works in
development mode, uses special runtime logic, does not support partial
rendering
- *internal implementation of `act`* – private, works in both
development and productionm modes, only used by the React Core test
suite, uses no special runtime logic, supports partial rendering (i.e.
`toFlushAndYieldThrough`)
The internal implementation should mostly match the public
implementation's behavior, but since it's a private API, it doesn't have
to match exactly. It works by mocking the test environment: it uses a
mock build of Scheduler to flush rendering tasks, and Jest's mock timers
to flush Suspense placeholders.
---
In this first commit, I've added the internal forks of `act` and
migrated our tests to use them. The public `act` implementation is
unaffected for now; I will leave refactoring/clean-up for a later step.
And `useDeferredValue`.
The options were already disabled in previous commits, so this doesn't
change any behavior. I upated type signatures and cleaned up the hook
implementation a bit — no longer have to wrap the `start` method with
`useCallback`, because its only remaining dependency is a `setState`
method, which never changes. Instead, we can store the `start` method
on a ref.
Now that the options in SuspenseConfig are no longer supported, the
only thing we use it for is to track whether an update is part of
a transition.
I've renamed `ReactCurrentBatchConfig.suspense` to
`ReactCurrentBatchConfig.transition`, and changed the type to a number.
The number is always either 0 or 1. I could have made it a boolean;
however, most likely this will eventually be either a Lane or an
incrementing identifier.
The `withSuspenseConfig` export still exists until we've removed
all the callers from www.
* Add "unstbale_" prefix to mutable source APIs
* DebugHooks no longer calls useMutableSource() on init
This was causing an observable behavioral difference between experimental DEV and PROD builds.
We don't initialize stack position for other composite hooks (e.g. useDeferredValue, useTransition, useOpaqueIdentifier). If we did, it would cause the same obesrvable behavioral difference.
We've been shipping unprefixed experimental APIs (like `createRoot` and
`useTransition`) to the Experimental release channel, with the rationale
that because these APIs do not appear in any stable release, we're free
to change or remove them later without breaking any downstream projects.
What we didn't consider is that downstream projects might be tempted to
use feature detection:
```js
const useTransition = React.useTransition || fallbackUseTransition;
```
This pattern assumes that the version of `useTransition` that exists in
the Experimental channel today has the same API contract as the final
`useTransition` API that we'll eventually ship to stable.
To discourage feature detection, I've added an `unstable_` prefix to
all of our unstable APIs.
The Facebook builds still have the unprefixed APIs, though. We will
continue to support those; if we make any breaking changes, we'll
migrate the internal callers like we usually do. To make testing easier,
I added the `unstable_`-prefixed APIs to the www builds, too. That way
our tests can always use the prefixed ones without gating on the
release channel.
* Migrate conditional tests to gate pragma
I searched through the codebase for this pattern:
```js
describe('test suite', () => {
if (!__EXPERIMENTAL__) { // or some other condition
test("empty test so Jest doesn't complain", () => {});
return;
}
// Unless we're in experimental mode, none of the tests in this block
// will run.
})
```
and converted them to the `@gate` pragma instead.
The reason this pattern isn't preferred is because you end up disabling
more tests than you need to.
* Add flag for www release channels
Using a heuristic where I check a flag that is known to only be enabled
in www. I left a TODO to instead set the release channel explicitly in
each test config.
Some of our internal reconciler types have leaked into other packages.
Usually, these types are treated as opaque; we don't read and write
to its fields. This is good.
However, the type is often passed back to a reconciler method. For
example, React DOM creates a FiberRoot with `createContainer`, then
passes that root to `updateContainer`. It doesn't do anything with the
root except pass it through, but because `updateContainer` expects a
full FiberRoot, React DOM is still coupled to all its fields.
I don't know if there's an idiomatic way to handle this in Flow. Opaque
types are simlar, but those only work within a single file. AFAIK,
there's no way to use a package as the boundary for opaqueness.
The immediate problem this presents is that the reconciler refactor will
involve changes to our internal data structures. I don't want to have to
fork every single package that happens to pass through a Fiber or
FiberRoot, or access any one of its fields. So my current plan is to
share the same Flow type across both forks. The shared type will be a
superset of each implementation's type, e.g. Fiber will have both an
`expirationTime` field and a `lanes` field. The implementations will
diverge, but not the types.
To do this, I lifted the type definitions into a separate module.
* Add useOpaqueIdentifier Hook
We currently use unique IDs in a lot of places. Examples are:
* `<label for="ID">`
* `aria-labelledby`
This can cause some issues:
1. If we server side render and then hydrate, this could cause an
hydration ID mismatch
2. If we server side render one part of the page and client side
render another part of the page, the ID for one part could be
different than the ID for another part even though they are
supposed to be the same
3. If we conditionally render something with an ID , this might also
cause an ID mismatch because the ID will be different on other
parts of the page
This PR creates a new hook `useUniqueId` that generates a different
unique ID based on whether the hook was called on the server or client.
If the hook is called during hydration, it generates an opaque object
that will rerender the hook so that the IDs match.
Co-authored-by: Andrew Clark <git@andrewclark.io>
* Enable prefer-const rule
Stylistically I don't like this but Closure Compiler takes advantage of
this information.
* Auto-fix lints
* Manually fix the remaining callsites
* Revert "ReactDOM.useEvent: enable on internal www and add inspection test (#18395)"
This reverts commit e0ab1a429d.
* Revert "ReactDOM.useEvent: Add support for experimental scopes API (#18375)"
This reverts commit a16b349745.
* ReactDOM.useEvent: Add support for experimental scopes API
* Bugfix: Suspended update must finish to unhide
When we commit a fallback, we cannot unhide the content without including
the level that originally suspended. That's because the work at level
outside the boundary (i.e. everything that wasn't hidden during that
render) already committed.
* Test unblocking with a high-pri update
* Rename lower case isomorphic default exports modules to upper case named exports
We're somewhat inconsistent here between e.g. ReactLazy and memo.
Let's pick one.
This also moves the responder, fundamental, scope creators from shared
since they're isomorphic and same as the other creators.
* Move some files that are specific to the react-reconciler from shared
Individual renderers are allowed to deep require into the reconciler.
* Move files specific to react-dom from shared
react-interactions is right now dom specific (it wasn't before) so we can
type check it together with other dom stuff. Avoids the need for
a shared ReactDOMTypes to be checked by RN for example.
* Move ReactWorkTags to the reconciler
* Move createPortal to export from reconciler
Otherwise Noop can't access it since it's not allowed deep requires.
useMutableSource hook
useMutableSource() enables React components to safely and efficiently read from a mutable external source in Concurrent Mode. The API will detect mutations that occur during a render to avoid tearing and it will automatically schedule updates when the source is mutated.
RFC: reactjs/rfcs#147
* Only use Rollup's CommonJS plugin for "react-art"
We still need it for the "art" UMD builds but nothing else should have
CommonJS dependencies anymore.
* react-debug-tools and jest-react should leave object-assign as an external dep
This avoids it being compiled into the output.
* Move remaining things to named exports
The interesting case here is the noop renderers. The wrappers around the
reconciler now changed to use a local export that gets mutated.
ReactNoop and ReactNoopPersistent now have to destructure the object to
list out the names it's going to export. We should probably refactor
ReactNoop away from createReactNoop. Especially since it's also not Flow
typed.
* Switch interactions to star exports
This will have esModule compatibility flag on them. They should ideally
export default instead.
The useState hook has always composed the useReducer hook. 1:1 composition like this is fine.
But some more recent hooks (e.g. useTransition, useDeferredValue) compose multiple hooks internally. This breaks react-debug-tools because it causes off-by-N errors when the debug tools re-renders the function.
For example, if a component were to use the useTransition and useMemo hooks, the normal hooks dispatcher would create a list of first state, then callback, then memo hooks, but the debug tools package would expect a list of transition then memo. This can break user code and cause runtime errors in both the react-debug-tools package and in product code.
This PR fixes the currently broken hooks by updating debug tools to be aware of the composite hooks (how many times it should call nextHook essentially) and adds tests to make sure they don't get out of sync again. We'll need to add similar tests for future composite hooks (like useMutableSource #18000).
* Add options for forked entry points
We currently fork .fb.js entry points. This adds a few more options.
.modern.fb.js - experimental FB builds
.classic.fb.js - stable FB builds
.fb.js - if no other FB build, use this for FB builds
.experimental.js - experimental builds
.stable.js - stable builds
.js - used if no other override exists
This will be used to have different ES exports for different builds.
* Switch React to named exports
* Export named exports from the export point itself
We need to re-export the Flow exported types so we can use them in our code.
We don't want to use the Flow types from upstream since it doesn't have the non-public APIs that we have.
This should be able to use export * but I don't know why it doesn't work.
This actually enables Flow typing of React which was just "any" before.
This exposed some Flow errors that needs fixing.
* Create forks for the react entrypoint
None of our builds expose all exports and they all differ in at least one
way, so we need four forks.
* Set esModule flag to false
We don't want to emit the esModule compatibility flag on our CommonJS
output. For now we treat our named exports as if they're CommonJS.
This is a potentially breaking change for scheduler (but all those apis
are unstable), react-is and use-subscription. However, it seems unlikely
that anyone would rely on this since these only have named exports.
* Remove unused Feature Flags
* Let jest observe the stable fork for stable tests
This lets it do the negative test by ensuring that the right tests fail.
However, this in turn will make other tests that are not behind
__EXPERIMENTAL__ fail. So I need to do that next.
* Put all tests that depend on exports behind __EXPERIMENTAL__
Since there's no way to override the exports using feature flags
in .intern.js anymore we can't use these APIs in stable.
The tradeoff here is that we can either enable the negative tests on
"stable" that means experimental are expected to fail, or we can disable
tests on stable. This is unfortunate since some of these APIs now run on
a "stable" config at FB instead of the experimental.
* Switch ReactDOM to named exports
Same strategy as React.
I moved the ReactDOMFB runtime injection to classic.fb.js
Since we only fork the entrypoint, the `/testing` entrypoint needs to
be forked too to re-export the same things plus `act`. This is a bit
unfortunate. If it becomes a pattern we can consider forking in the
module resolution deeply.
fix flow
* Fix ReactDOM Flow Types
Now that ReactDOM is Flow type checked we need to fix up its types.
* Configure jest to use stable entry for ReactDOM in non-experimental
* Remove additional FeatureFlags that are no longer needed
These are only flagging the exports and no implementation details so we
can control them fully through the export overrides.
* Update Flow to 0.84
* Fix violations
* Use inexact object syntax in files from fbsource
* Fix warning extraction to use a modern parser
* Codemod inexact objects to new syntax
* Tighten types that can be exact
* Revert unintentional formatting changes from codemod
* Add feature flags
* Add Chunk type and constructor
* Wire up Chunk support in the reconciler
* Update reconciler to reconcile Chunks against the render method
This allows the query and args to be updated.
* Drop the ref. Chunks cannot have refs anyway.
* Add Chunk checks in more missing cases
* Rename secondArg
* Add test and fix lazy chunks
Not really a supported use case but for consistency I guess.
* Fix fragment test
