We have a different set of dispatchers that Flight uses. This also
includes the `jsx-runtime` which must also be aliased to use the right
version.
To ensure the right versions are used together we rename the export of
the SharedInternals from 'react' and alias it in relevant bundles.
This is similar to #28771 but for isomorphic. We need a make over for
these dispatchers anyway so this is the first step. Also helps flush out
some internals usage that will break anyway.
It flattens the inner mutable objects onto the ReactSharedInternals.
`react-server` precludes loading code that expects to be run in a client
context. This includes react-dom/client react-dom/server
react-dom/unstable_testing react-dom/profiling and react-dom/static
This update makes importing any of these client only entrypoints an
error
Treat async (boolean prop) consistently with Float. Previously float
checked if `props.async === true` (or not true) but the rest of
react-dom considers anything truthy that isn't a function or symbol as
`true`. This PR normalizes the Float behavior.
Stacked on #28751
Historically explicit hydration scheduling used the reconciler's update
priority to schedule the hydration. There was a lingering todo to switch
to using event priority in the absence of an explicit update priority.
This change updates the hydration priority by referring to the event
priority if no update priority is set
Stacked on #28771
ReactDOMCurrentDispatcher has longer property names for various methods.
These methods are only ever called internally and don't need to be
represented with as many characters. This change shortens the names and
aligns them with the hint codes we use in Flight. This alignment is
passive since not all dispatcher methods will exist as flight
instructions but where they can line up it seems reasonable to make them
do so
Stacked on #28751
ReactDOMSharedInternals uses properties of considerable length to model
mutuable state. These properties are not mangled during minification and
contribute a not insigificant amount to the uncompressed bundle size and
to a lesser degree compressed bundle size.
This change rewrites the DOMInternals in a way that shortens property
names so we can have smaller builds.
It also treats the entire object as a mutable container rather than
having different mutable sub objects.
The same treatment should be given to ReactSharedInternals
We used to assume that outlined models are emitted before the reference
(which was true before Blobs). However, it still wasn't safe to assume
that all the data will be available because an "import" (client
reference) can be async and therefore if it's directly a child of an
outlined model, it won't be able to update in place.
This is a similar problem as the one hit by @unstubbable in #28669 with
elements, but a little different since these don't follow the same way
of wrapping.
I don't love the structuring of this code which now needs to pass a
first class mapper instead of just being known code. It also shares the
host path which is just an identity function. It wouldn't necessarily
pass my own review but I don't have a better one for now. I'd really
prefer if this was done at a "row" level but that ends up creating even
more code.
Add test for Blob in FormData and async modules in Maps.
We landed a flag to disable test utils in many builds but we need to
fork the entrypoint to make it work with tests properly. This also
removes test-utils implementations from builds that do not support it.
Currently in OSS builds the only thing in test-utils is a reexport of
`act`
## Summary
1. RDT browser extension's content scripts will now ship source maps
(without source in prod, to save some bundle size).
2. `installHook` content script will be ignore listed via `ignoreList`
field in the corresponding source map.
3. Previously, source map for backend file used `x_google_ignoreList`
naming, now `ignoreList`.
## How did you test this change?
1. `ignoreList-test.js`
2. Tested manually that I don't see `installHook` in stack traces when
`console.error` is called.
This PR moves `flushSync` out of the reconciler. there is still an
internal implementation that is used when these semantics are needed for
React methods such as `unmount` on roots.
This new isomorphic `flushSync` is only used in builds that no longer
support legacy mode.
Additionally all the internal uses of flushSync in the reconciler have
been replaced with more direct methods. There is a new
`updateContainerSync` method which updates a container but forces it to
the Sync lane and flushes passive effects if necessary. This combined
with flushSyncWork can be used to replace flushSync for all instances of
internal usage.
We still maintain the original flushSync implementation as
`flushSyncFromReconciler` because it will be used as the flushSync
implementation for FB builds. This is because it has special legacy mode
handling that the new isomorphic implementation does not need to
consider. It will be removed from production OSS builds by closure
though
Currently updatePriority is tracked in the reconciler. `flushSync` is
going to be implemented reconciler agnostic soon and we need to move the
tracking of this state to the renderer and out of reconciler. This
change implements new renderer bin dings for getCurrentUpdatePriority
and setCurrentUpdatePriority.
I was originally going to have the getter also do the event priority
defaulting using window.event so we eliminate getCur rentEventPriority
but this makes all the callsites where we store the true current
updatePriority on the stack harder to work with so for now they remain
separate.
I also moved runWithPriority to the renderer since it really belongs
whereever the state is being managed and it is only currently exposed in
the DOM renderer.
Additionally the current update priority is not stored on
ReactDOMSharedInternals. While not particularly meaningful in this
change it opens the door to implementing `flushSync` outside of the
reconciler
Follow up to #28768.
The modern JSX runtime (`jsx`) does not need to check if each prop is a
direct property with `hasOwnProperty` because the compiler always passes
a plain object.
I'll leave the check in the old JSX runtime (`createElement`) since that
one can be called manually with any kind of object, and if there were
old user code that relied on this for some reason, it would be using
that runtime.
We currently support FormData for Replies mainly for Form Actions. This
supports it in the other direction too which lets you return it from an
action as the response. Mainly for parity.
We don't really recommend that you just pass the original form data back
because the action is supposed to be able to clear fields and such but
you could potentially at least use this as the format and could clear
some fields.
We could potentially optimize this with a temporary reference if the
same object was passed to a reply in case you use it as a round trip to
avoid serializing it back again. That way the action has the ability to
override it to clear fields but if it doesn't you get back the same as
you sent.
#28755 adds support for Blobs when the `enableBinaryFlight` is enabled
which allows them to be used inside FormData too.
(Unless "key" is spread onto the element.)
Historically, the JSX runtime clones the props object that is passed in.
We've done this for two reasons.
One reason is that there are certain prop names that are reserved by
React, like `key` and (before React 19) `ref`. These are not actual
props and are not observable by the target component; React uses them
internally but removes them from the props object before passing them to
userspace.
The second reason is that the classic JSX runtime, `createElement`, is
both a compiler target _and_ a public API that can be called manually.
Therefore, we can't assume that the props object that is passed into
`createElement` won't be mutated by userspace code after it is passed
in.
However, the new JSX runtime, `jsx`, is not a public API — it's solely a
compiler target, and the compiler _will_ always pass a fresh, inline
object. So the only reason to clone the props is if a reserved prop name
is used.
In React 19, `ref` is no longer a reserved prop name, and `key` will
only appear in the props object if it is spread onto the element.
(Because if `key` is statically defined, the compiler will pass it as a
separate argument to the `jsx` function.) So the only remaining reason
to clone the props object is if `key` is spread onto the element, which
is a rare case, and also triggers a warning in development.
In a future release, we will not remove a spread key from the props
object. (But we'll still warn.) We'll always pass the object straight
through.
The expected impact is much faster JSX element creation, which in many
apps is a significant slice of the overall runtime cost of rendering.
`delete` causes an object (in V8, and maybe other engines) to deopt to a
dictionary instead of a class. Instead of `assign` + `delete`, manually
iterate over all the properties, like the JSX runtime does.
To avoid copying the object twice I moved the `ref` prop removal to come
before handling default props. If we already cloned the props to remove
`ref`, then we can skip cloning again to handle default props.
We currently support Blobs when passing from Client to Server so this
adds it in the other direction for parity - when `enableFlightBinary` is
enabled.
We intentionally only support the `Blob` type to pass-through, not
subtype `File`. That's because passing additional meta data like
filename might be an accidental leak. You can still pass a `File`
through but it'll appear as a `Blob` on the other side. It's also not
possible to create a faithful File subclass in all environments without
it actually being backed by a file.
This implementation isn't great but at least it works. It creates a few
indirections. This is because we need to be able to asynchronously emit
the buffers but we have to "block" the parent object from resolving
while it's loading.
Ideally, we should be able to create the Blob on the client early and
then stream in it lazily. Because the Blob API doesn't guarantee that
the data is available synchronously. Unfortunately, the native APIs
doesn't have this. We could implement custom versions of all the data
read APIs but then the blobs still wouldn't work with native APIs. So we
just have to wait until Blob accepts a stream in the constructor.
We should be able to stream each chunk early in the protocol though even
though we can't unblock the parent until they've all loaded. I didn't do
this yet mostly because of code structure and I'm lazy.
This implements the concept of a DEV-only "owner" for Server Components.
The owner concept isn't really super useful. We barely use it anymore,
but we do have it as a concept in DevTools in a couple of cases so this
adds it for parity. However, this is mainly interesting because it could
be used to wire up future owner-based stacks.
I do this by outlining the DebugInfo for a Server Component
(ReactComponentInfo). Then I just rely on Flight deduping to refer to
that. I refer to the same thing by referential equality so that we can
associate a Server Component parent in DebugInfo with an owner.
If you suspend and replay a Server Component, we have to restore the
same owner. To do that, I did a little ugly hack and stashed it on the
thenable state object. Felt unnecessarily complicated to add a stateful
wrapper for this one dev-only case.
The owner could really be anything since it could be coming from a
different implementation. Because this is the first time we have an
owner other than Fiber, I have to fix up a bunch of places that assumes
Fiber. I mainly did the `typeof owner.tag === 'number'` to assume it's a
Fiber for now.
This also doesn't actually add it to DevTools / RN Inspector yet. I just
ignore them there for now.
Because Server Components can be async the owner isn't tracked after an
await. We need per-component AsyncLocalStorage for that. This can be
done in a follow up.
Based on:
- #28464
---
This moves the entire string ref implementation out Fiber and into the
JSX runtime. The string is converted to a callback ref during element
creation. This is a subtle change in behavior, because it will have
already been converted to a callback ref if you access element.prop.ref
or element.ref. But this is only for Meta, because string refs are
disabled entirely in open source. And if it leads to an issue in
practice, the solution is to switch to a different ref type, which Meta
is going to do regardless.
In prod, the `_owner` field is only used for string refs so if we have
string refs disabled, we don't need this field. In fact, that's one of
the big benefits of deprecating them.
This removes defaultProps support for all component types except for
classes. We've chosen to continue supporting defaultProps for classes
because lots of older code relies on it, and unlike function components,
(which can use default params), there's no straightforward alternative.
By implication, it also removes support for setting defaultProps on
`React.lazy` wrapper. So this will not work:
```js
const MyClassComponent = React.lazy(() => import('./MyClassComponent'));
// MyClassComponent is not actually a class; it's a lazy wrapper. So
// defaultProps does not work.
MyClassComponent.defaultProps = { foo: 'bar' };
```
However, if you set the default props on the class itself, then it's
fine.
For classes, this change also moves where defaultProps are resolved.
Previously, defaultProps were resolved by the JSX runtime. This change
is only observable if you introspect a JSX element, which is relatively
rare but does happen.
In other words, previously `<ClassWithDefaultProp />.props.aDefaultProp`
would resolve to the default prop value, but now it does not.
Follows #28695
Now that the action has run successfully in debug mode
([logs](https://github.com/facebook/react/actions/runs/8532177618/job/23372921455#step:2:35)),
let's enable it to persist changes.
Also changes the number of operations per run from the default of 30 to
100 since we have a large backlog of issues and PRs to work through.
Finally adds enhancement label as exempt from stale.
We basically have four kinds of recoverable errors:
- Hydration mismatches.
- Server errored but client didn't.
- Hydration render errored but client render didn't (in Root or Suspense
boundary).
- Concurrent render errored but synchronous render didn't.
For the first three we log an additional error that the root or Suspense
boundary didn't error. This provides some context about what happened.
However, the problem is that for hydration mismatches that's unnecessary
extra context that is confusing. We also don't log any additional
context for concurrent render errors that could recover. This used to be
the only recoverable error so it didn't need extra context but now we
need to distinguish them. When we log these to `reportError` it's
confusing to just see the error because you didn't see anything error on
the page. It's also hard to group them together as one.
In this PR, I remove the unnecessary context for hydration mismatches.
For hydration and concurrent errors, I now wrap them in an error that
describes that what happened but then use the new `cause` field to link
the original error so we can keep that as the cause. The error that
happened was that hydration client rendered or you deopted to sync
render, the cause of that error is some other error.
For server errors, we control the Error object so I already had added
some context to that error object's message. Since we hide the message
in prod, it's nice not to have the raw message in DEV neither. We could
potentially split these into two errors for parity though.
Follow up to #28684.
V8 includes the message in the stack and printed errors include just the
stack property which is assumed to contain the message. Without this,
the prefix doesn't get printed in the console.
<img width="578" alt="Screenshot 2024-04-03 at 6 32 04 PM"
src="https://github.com/facebook/react/assets/63648/d98a2db4-6ebc-4805-b669-59f449dfd21f">
A possible alternative would be to use a nested error with a `cause`
like #28736 but that would need some more involved serializing since
this prefix is coming from the server. Perhaps as a separate attribute.
Moving this to `internal-test-utils` so I can add helpers in the next PR
for:
- assertLogDev
- assertWarnDev
- assertErrorDev
Which will be exported from `internal-test-utils`. This isn't strictly
necessary, but it makes the factoring nicer, so internal-test-until
doesn't need to depend on `scripts/jest`.
Cleanup enableUseRefAccessWarning flag
I don't think this flag has a path forward in the current
implementation. The detection by stack trace is too brittle to detect
the lazy initialization pattern reliably (see e.g. some internal tests
that expect the warning because they use lazy intialization, but a
slightly different pattern then the expected pattern.
I think a new version of this could be to fully ban ref access during
render with an alternative API for the exceptional cases that today
require ref access during render.
Remove @providesModule remnants
Removes `@providesModule` from the generated RN modules and CI
validation that no `@providesModule` is added which should no longer be
needed as this has been the case for years now.
When a ref is passed to a class component, the class instance is
attached to the ref's current property automatically. This different
from function components, where you have to do something extra to attach
a ref to an instance, like passing the ref to `useImperativeHandle`.
Existing class component code is written with the assumption that a ref
will not be passed through as a prop. For example, class components that
act as indirections often spread `this.props` onto a child component. To
maintain this expectation, we should remove the ref from the props
object ("consume" it) before passing it to lifecycle methods. Without
this change, much existing code will break because the ref will attach
to the inner component instead of the outer one.
This is not an issue for function components because we used to warn if
you passed a ref to a function component. Instead, you had to use
`forwardRef`, which also implements this "consuming" behavior.
There are a few places in the reconciler where we modify the fiber's
internal props object before passing it to userspace. The trickiest one
is class components, because the props object gets exposed in many
different places, including as a property on the class instance.
This was already accounted for when we added support for setting default
props on a lazy wrapper (i.e. `React.lazy` that resolves to a class
component).
In all of these same places, we will also need to remove the ref prop
when `enableRefAsProp` is on.
Closes#28602
---------
Co-authored-by: Jan Kassens <jan@kassens.net>
Only the FB entry point has legacy mode now so we can move the remaining
code in there.
Also enable disableLegacyMode in modern www builds since it doesn't
expose those entry points.
Now dependent on #28709.
---------
Co-authored-by: Josh Story <story@hey.com>
Saves some bytes and ensures that we're actually disabling it.
Turns out this flag wasn't disabling React Native/Fabric, React Noop and
React ART legacy modes so those are updated too.
Should be rebased on #28681.
This PR relands #28672 on top of the flag removal and the test
demonstrating a breakage in Suspense for legacy mode.
React has deprecated module pattern Function Components for many years
at this point. Supporting this pattern required React to have a concept
of an indeterminate component so that when a component first renders it
can turn into either a ClassComponent or a FunctionComponent depending
on what it returns. While this feature was deprecated and put behind a
flag it is still in stable. This change remvoes the flag, removes the
warnings, and removes the concept of IndeterminateComponent from the
React codebase.
While removing IndeterminateComponent type Seb and I discovered that we
needed a concept of IncompleteFunctionComponent to support Suspense in
legacy mode. This new work tag is only needed as long as legacy mode is
around and ideally any code that considers this tag will be excludable
from OSS builds once we land extra gates using `disableLegacyMode` flag.
Pulling this out of #28657.
This runs react-art in concurrent mode if disableLegacyMode is true.
Effectively this means that the OSS version will be in concurrent mode
and the `.modern.js` version for Meta will be in concurrent mode, once
the flag flips for modern, but the `.classic.js` version for Meta will
be in legacy mode.
Updates flowing in from above flush synchronously so that they commit as
a unit. This also ensures that refs are resolved before the parent life
cycles. setStates deep in the tree will now be batched using "discrete"
priority but should still happen same task.
In React DOM, in general, we don't differentiate between `null` and
`undefined` because we expect to target DOM APIs. When we're setting a
property on a Custom Element, in the new heuristic, the goal is to allow
passing whatever data type instead of normalizing it. Switching between
`undefined` and `null` as an explicit value should therefore be
respected.
However, in this mode if `undefined` is used for the initial value, we
don't actually set the property at all. If passing `null` we will now
initialize it to the value `null`. Meaning `undefined` kind of
represents the default.
### Removing Properties
There is a pretty complex edge case which is what should happen when a
prop used to exist but was removed from the props object. This doesn't
have any kind of defined semantics. It really should mean - return to
"default". Because in the declarative world it means the same as if it
was just created - i.e. we can't just leave it as it was.
The closest might be `delete object.property` but that's not really the
intended way that properties on custom elements / classes are supposed
to operate. Additionally, for a property to even hit our heuristic it
must pass the `in` test and must exist to being with so the default must
have a value.
Since the point of these properties is to contain any kind of type,
there isn't really a conceptual default value. E.g. a numeric default
value might be zero `0` while a default string might be empty `""` and
default object might `null`. Additionally, the conceptual default can
really be initialized to anything. There's also varied precedence in the
ecosystem here and really no consensus. Anything we pick would be kind
of wrong, so we used to just pick `null`.
_The safest way to consume a Custom Element is to always pass the same
set of props._
JS does have a concept of a "default value" though and that is described
as the value `undefined`. That's why default argument / object property
initializers are initialized if the value is `undefined`.
The problem with using `undefined` as value is that [you shouldn't
actually ever set the value of a class property to
`undefined`](https://twitter.com/sebmarkbage/status/1774082540296388752).
A property should always be initialized to some value. It can't be left
missing and shouldn't be initialized to the value `undefined` for hidden
class optimizations. If we just mutate it to be `undefined` it would be
potentially bad for perf and shouldn't really be the value after
removing property - it should be returned to default.
Every property should really have a setter to be useful since it is what
is used to trigger reactivity when it changes. Sometimes you can just
use the properties passively when something else happens but most of the
time it should be a setter but to reach parity with DOM it should really
be always so that the active value can be normalized.
Those setters can have default argument initializers to represent what
the default value should be. Therefore Custom Element properties should
be used like this:
```js
class CustomElement extends HTMLElement {
_textLabel = '';
_price = 0;
_items = null;
constructor() {
super();
}
set textLabel(value = '') {
this._textLabel = value;
}
get textLabel() {
return this._textLabel;
}
set price(value = 0) {
this._price = value;
}
get price() {
return this._price;
}
set items(value = null) {
this._items = value;
}
get items() {
return this._items;
}
}
```
The default initializer can be used to initialize a value back to its
original default when `undefined` is passed to it. Therefore, we pass
`undefined`, not because we expect that to be the value of a property
but because that's the value that represents "return to default".
This fixes#28203 but not really for the reason specified in the issue.
We don't expect you to actually store the `undefined` value but to use a
setter to set the property to something else that represents the
default. When we initialize the element the first time, we won't set
anything if it's the value `undefined` so we assume that the property
initializers running in the constructor is going to set the same default
value as if we set the property to `undefined`.
cc @josepharhar
Jan Kassens
Ricky
Sebastian Markbåge
Josh Story
Hugo Sales
Ruslan Lesiutin
Andrew Clark
Sebastian Silbermann
Surav Shrestha
Jack Pope
Joseph Savona