Commit Graph

1815 Commits

Author SHA1 Message Date
Josh Story
67ff96e12d [Tests][Fizz] Test script runtime even when external runtime is available (#28794)
Previously if the external runtime was enabled Fizz tests would use it
exclusively. However now that this flag is enabled for OSS and Meta
builds this means we were no longer testing the inline script runtime.
This changes the test flags to produce some runs where we test the
inline script runtime and others where we test the external runtime

the external runtime will be tested if the flag is enabled and
* Meta Builds: variant is true
* OSS Builds: experiemental is true

this gives us decent coverage. long term we should probably bring
variant to OSS builds since we will eventually want to test both modes
even when the external runtime is stable.
2024-04-09 11:50:02 -07:00
Josh Story
7f93cb41c8 [DOM] Infer react-server entries bundles if not explicitly configured (#28795)
When packaging we want to infer that a bundle exists for a
`react-server` file even if it isn't explicitly configured. This is
useful in particular for the react-server entrypoints that error on
import that were recently added to `react-dom`

This change also cleans up a wayward comment left behind in a prior PR
2024-04-09 10:39:25 -07:00
Sebastian Markbåge
f613165357 Rename SECRET INTERNALS to __CLIENT_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE (#28789)
Follow up to #28783 and #28786.

Since we've changed the implementations of these we can rename them to
something a bit more descriptive while we're at it, since anyone
depending on them will need to upgrade their code anyway.

"react" with no condition:
`__CLIENT_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE`
"react" with "react-server" condition:
`__SERVER_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE`
"react-dom":
`__DOM_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE`
2024-04-09 12:20:22 -04:00
Ricky
9644d206e8 Soften useFormState warning (#28788)
It's not deprecated, it's really just renamed. Let's make the warning
less scary.
2024-04-08 23:22:17 -04:00
Sebastian Markbåge
d50323eb84 Flatten ReactSharedInternals (#28783)
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.
2024-04-08 19:23:23 -04:00
Hugo Sales
dfd3d5af83 Add support for transition{run,start,cancel} events (#27345) 2024-04-08 23:23:04 +02:00
Josh Story
97c90ed883 [DOM] Shrink ReactDOMCurrentDispatcher method names (#28770)
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
2024-04-08 13:54:30 -07:00
Josh Story
9007fdc8f1 [DOM] Shrink ReactDOMSharedInternals source representation (#28771)
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
2024-04-08 13:39:39 -07:00
Josh Story
01bb3c5632 [TestUtils] Build limited test-utils (#28782)
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`
2024-04-08 12:27:20 -07:00
Josh Story
4c12339ce3 [DOM] move flushSync out of the reconciler (#28500)
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
2024-04-08 09:03:20 -07:00
Josh Story
8e1462e8c4 [Fiber] Move updatePriority tracking to renderers (#28751)
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
2024-04-08 08:53:17 -07:00
Andrew Clark
e3ebcd54b9 Move string ref coercion to JSX runtime (#28473)
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.
2024-04-05 10:53:11 -04:00
Andrew Clark
48b4ecc901 Remove defaultProps support (except for classes) (#28733)
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.
2024-04-04 10:59:19 -04:00
Sebastian Markbåge
6090cab099 Use a Wrapper Error for onRecoverableError with a "cause" Field for the real Error (#28736)
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.
2024-04-03 21:53:07 -04:00
Ricky
a5aedd1e15 Move console mocks to internal-test-utils (#28710)
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`.
2024-04-03 16:02:04 -04:00
Andrew Clark
3761acb42b Classes consume ref prop during SSR, too (#28731)
Same as #28719 but for SSR.
2024-04-03 12:55:57 -04:00
Jan Kassens
7a2609eedc Cleanup enableBigIntSupport flag (#28711)
Cleanup enableBigIntSupport flag
2024-04-03 09:25:02 -04:00
Josh Story
cb6dc7a6a0 [FB] use modern entrypoint in tests (#28724)
Removes the entrypoint hack in tests since we gate legacy mode tests now
2024-04-02 22:23:54 -07:00
Andrew Clark
dc545c8d6e Fix: Class components should "consume" ref prop (#28719)
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>
2024-04-02 23:15:04 -04:00
Sebastian Markbåge
8f55a6aa57 Move ReactDOMLegacy implementation into RootFB (#28656)
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>
2024-04-02 21:56:23 -04:00
Josh Story
5998a77519 Reland #28672: Remove IndeterminateComponent (#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.
2024-04-02 17:42:43 -07:00
Sebastian Markbåge
48ec17b865 Differentiate null and undefined in Custom Elements - removing sets to undefined (#28716)
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
2024-04-02 11:48:27 -04:00
Ricky
e9ae2c8f35 Clean up console.log tests (#28693)
Followups to https://github.com/facebook/react/pull/28680

One of these test don't need to use `console.log`. 

The others are specifically testing `console.log` behavior, so I added a
comment.
2024-04-01 10:50:48 -04:00
Sebastian Markbåge
df95577db0 Finish cleaning up digest from onRecoverableError (#28686)
Don't need to track it separately on the captured value anymore.

Shouldn't be in the types.

I used a getter for the warning instead because Proxies are kind of
heavy weight options for this kind of warning. We typically use getters.
2024-03-30 18:32:20 -04:00
Timothy Yung
9f835e69ab Suppress console output in unit tests (#28680) 2024-03-30 09:36:23 -07:00
Sebastian Markbåge
b9149cc6e6 Include regular stack trace in serialized errors from Fizz (#28684)
We previously only included the component stack.
    
Cleaned up the fields in Fizz server that wasn't using consistent hidden
classes in dev vs prod.

Added a prefix to errors serialized from server rendering. It can be a
bit confusing to see where this error came from otherwise since it
didn't come from elsewhere on the client. It's really kind of confusing
with other recoverable errors that happen on the client too.
2024-03-30 11:08:54 -04:00
Sebastian Markbåge
5d4b7587da Don't let error boundaries catch errors during hydration (#28675)
When an error boundary catches an error during hydration it'll try to
render the error state which will then try to hydrate that state,
causing hydration warnings.

When an error happens inside a Suspense boundary during hydration, we
instead let the boundary catch it and restart a client render from
there. However, when it's in the root we instead let it fail the root
and do the sync recovery pass. This didn't consider that we might hit an
error boundary first so this just skips the error boundary in that case.

We should probably instead let the root do a concurrent client render in
this same pass instead to unify with Suspense boundaries.
2024-03-29 16:43:22 -04:00
Jack Pope
6cd6ba703d Land enableNewBooleanProps everywhere (#28676)
Rolled out internally. Removing flag.
2024-03-29 16:02:32 -04:00
Ricky
18812b645c Warn when using useFormState (#28668)
## Overview

useFormState has been replaced with useActionState. Warn when it's used.

Also removes the `experimental_useFormState` warnings.
2024-03-29 13:40:54 -04:00
Andrey Lunyov
eb510a3304 Land enableCustomElementPropertySupport for React 19 (#27450)
We've rolled out this flag internally on WWW. This PR removed flag
`enableCustomElementPropertySupport`

Test plan:
 -- `yarn test`

Co-authored-by: Ricky Hanlon <rickhanlonii@gmail.com>
2024-03-29 13:06:07 -04:00
Jan Kassens
a73c3450e1 Remove module pattern function component support (flag only) (#28671)
Remove module pattern function component support (flag only)

> This is a redo of #27742, but only including the flag removal,
excluding further simplifications.

The module pattern

```
function MyComponent() {
  return {
    render() {
      return this.state.foo
    }
  }
}
```

has been deprecated for approximately 5 years now. This PR removes
support for this pattern.
2024-03-29 11:16:17 -04:00
Ricky
f269074723 Revert "Remove module pattern function component support" (#28670)
This breaks internal tests, so must be something in the refactor. Since
it's the top commit let's revert and split into two PRs, one that
removes the flag and one that does the refactor, so we can find the bug.
2024-03-29 10:10:11 -04:00
Josh Story
cc56bed38c Remove module pattern function component support (#27742)
The module pattern

```
function MyComponent() {
  return {
    render() {
      return this.state.foo
    }
  }
}
```

has been deprecated for approximately 5 years now. This PR removes
support for this pattern. It also simplifies a number of code paths in
particular related to the concept of `IndeterminateComponent` types.
2024-03-28 13:08:08 -07:00
Ricky
63651c49e0 Noop unstable_batchedUpdates (#28120)
## Overview

`unstable_batchedUpdates` is effectively a no-op outside of legacy mode,
this PR makes it an actual no-op outside legacy mode.
2024-03-28 14:15:37 -04:00
Marius Craciunoiu
78328c0c4d Add support for preload media to ReactDOM (#28635)
This PR adds support for `media` option to `ReactDOM.preload()`, which
is needed when images differ between screen sizes (for example mobile vs
desktop)
2024-03-28 10:04:59 -07:00
Ricky
05797ccebd s/form state/action state (#28631)
Rename internals from "form state" to "action state"
2024-03-28 11:34:24 -04:00
Josh Story
299a9c0598 [Fiber] Remove the digest property from errorInfo passed to onRecoverableError (#28222)
Removes the digest property from errorInfo passed to onRecoverableError
when handling an error propagated from the server. Previously we warned
in Dev but still provided the digest on the errorInfo object. This
change removes digest from error info but continues to warn if it is
accessed. The reason for retaining the warning is the version with the
warning was not released as stable but we will include this deprecated
removal in our next major so we should communicate this change at
runtime.
2024-03-28 08:01:35 -07:00
Sebastian Markbåge
e10a7b5cd5 Don't log onRecoverableError if the current commit fail (#28665)
We didn't recover after all.

Currently we might log a recoverable error in the recovery pass. E.g.
the SSR server had an error. Then the client component fails to render
which errors again. This ends up double logging.

So if we fail to actually complete a fully successful commit, we ignore
any recoverable errors because we'll get real errors logged.

It's possible that this might cover up some other error that happened at
the same time.
2024-03-28 10:39:49 -04:00
Sebastian Markbåge
323b6e98a7 Remove errorHydratingContainer (#28664)
I originally added this in #21021 but I didn't mention why and I don't
quite remember why. Maybe because there were no other message? However
at the time the recoverable errors mechanism didn't exist.

Today I believe all cases where this happens will trigger another
recoverable error. Namely these two:


9f33f699e4/packages/react-reconciler/src/ReactFiberBeginWork.js (L1442-L1446)


9f33f699e4/packages/react-reconciler/src/ReactFiberBeginWork.js (L2962-L2965)

Therefore this is just an extra unnecessary log.
2024-03-27 23:48:18 -04:00
Josh Story
9ad40b1440 [react-dom] Remove findDOMNode from OSS builds (#28267)
In the next major `findDOMNode` is being removed. This PR removes the
API from the react-dom entrypoints for OSS builds and re-exposes the
implementation as part of internals.

`findDOMNode` is being retained for Meta builds and so all tests that
currently use it will continue to do so by accessing it from internals.
Once the replacement API ships in an upcoming minor any tests that were
using this API incidentally can be updated to use the new API and any
tests asserting `findDOMNode`'s behavior directly can stick around until
we remove it entirely (once Meta has moved away from it)
2024-03-27 14:43:12 -07:00
Josh Story
8436bcca62 [Fizz][Legacy] Remove renderToNodeStream (#28607)
Stacked on #28606 

renderToNodeStream has been deprecated since React 18 with a warning
indicating users should upgrade to renderToPipeableStream. This change
removes renderToNodeStream
2024-03-27 12:02:36 -07:00
Sebastian Silbermann
2b036d3f1f Deprecate act from react-dom/test-utils in favor of act from react (#28597) 2024-03-27 16:28:01 +01:00
Sebastian Silbermann
ec4d26ceb8 ReactDOM: Remove every test-util except act() (#28541) 2024-03-27 16:04:56 +01:00
Sebastian Markbåge
a053716077 Make onUncaughtError and onCaughtError Configurable (#28641)
Stacked on #28627.

This makes error logging configurable using these
`createRoot`/`hydrateRoot` options:

```
onUncaughtError(error: mixed, errorInfo: {componentStack?: ?string}) => void
onCaughtError(error: mixed, errorInfo: {componentStack?: ?string, errorBoundary?: ?React.Component<any, any>}) => void
onRecoverableError(error: mixed, errorInfo: {digest?: ?string, componentStack?: ?string}) => void
```

We already have the `onRecoverableError` option since before.

Overriding these can be used to implement custom error dialogs (with
access to the `componentStack`).

It can also be used to silence caught errors when testing an error
boundary or if you prefer not getting logs for caught errors that you've
already handled in an error boundary.

I currently expose the error boundary instance but I think we should
probably remove that since it doesn't make sense for non-class error
boundaries and isn't very useful anyway. It's also unclear what it
should do when an error is rethrown from one boundary to another.

Since these are public APIs now we can implement the
ReactFiberErrorDialog forks using these options at the roots of the
builds. So I unforked those files and instead passed a custom option for
the native and www builds.

To do this I had to fork the ReactDOMLegacy file into ReactDOMRootFB
which is a duplication but that will go away as soon as the FB fork is
the only legacy root.
2024-03-27 00:51:37 -04:00
Ricky
9f8daa6cb5 [Breaking] Remove disableJavaScriptURLs (#28615)
## Overview

This has landed, so we can remove the flag

## Changelog

This change blocks using javascript URLs such as:

```html
<a href="javascript:notfine">p0wned</a>
```

We previously announced dropping support for this via a warning:

> A future version of React will block javascript: URLs as a security
precaution. Use event handlers instead if you can. If you need to
generate unsafe HTML try using dangerouslySetInnerHTML instead.
2024-03-26 23:45:34 -04:00
Sebastian Markbåge
6786563f3c [Fiber] Don't Rethrow Errors at the Root (#28627)
Stacked on top of #28498 for test fixes.

### Don't Rethrow

When we started React it was 1:1 setState calls a series of renders and
if they error, it errors where the setState was called. Simple. However,
then batching came and the error actually got thrown somewhere else.
With concurrent mode, it's not even possible to get setState itself to
throw anymore.

In fact, all APIs that can rethrow out of React are executed either at
the root of the scheduler or inside a DOM event handler.
If you throw inside a React.startTransition callback that's sync, then
that will bubble out of the startTransition but if you throw inside an
async callback or a useTransition we now need to handle it at the hook
site. So in 19 we need to make all React.startTransition swallow the
error (and report them to reportError).

The only one remaining that can throw is flushSync but it doesn't really
make sense for it to throw at the callsite neither because batching.
Just because something rendered in this flush doesn't mean it was
rendered due to what was just scheduled and doesn't mean that it should
abort any of the remaining code afterwards. setState is fire and forget.
It's send an instruction elsewhere, it's not part of the current
imperative code.

Error boundaries never rethrow. Since you should really always have
error boundaries, most of the time, it wouldn't rethrow anyway.

Rethrowing also actually currently drops errors on the floor since we
can only rethrow the first error, so to avoid that we'd need to call
reportError anyway. This happens in RN events.

The other issue with rethrowing is that it logs an extra console.error.
Since we're not sure that user code will actually log it anywhere we
still log it too just like we do with errors inside error boundaries
which leads all of these to log twice.
The goal of this PR is to never rethrow out of React instead, errors
outside of error boundaries get logged to reportError. Event system
errors too.

### Breaking Changes

The main thing this affects is testing where you want to inspect the
errors thrown. To make it easier to port, if you're inside `act` we
track the error into act in an aggregate error and then rethrow it at
the root of `act`. Unlike before though, if you flush synchronously
inside of act it'll still continue until the end of act before
rethrowing.

I expect most user code breakages would be to migrate from `flushSync`
to `act` if you assert on throwing.

However, in the React repo we also have `internalAct` and the
`waitForThrow` helpers. Since these have to use public production
implementations we track these using the global onerror or process
uncaughtException. Unlike regular act, includes both event handler
errors and onRecoverableError by default too. Not just render/commit
errors. So I had to account for that in our tests.

We restore logging an extra log for uncaught errors after the main log
with the component stack in it. We use `console.warn`. This is not yet
ignorable if you preventDefault to the main error event. To avoid
confusion if you don't end up logging the error to console I just added
`An error occurred`.

### Polyfill

All browsers we support really supports `reportError` but not all test
and server environments do, so I implemented a polyfill for browser and
node in `shared/reportGlobalError`. I don't love that this is included
in all builds and gets duplicated into isomorphic even though it's not
actually needed in production. Maybe in the future we can require a
polyfill for this.

### Follow Ups

In a follow up, I'll make caught vs uncaught error handling be
configurable too.

---------

Co-authored-by: Ricky Hanlon <rickhanlonii@gmail.com>
2024-03-26 23:44:07 -04:00
Sebastian Markbåge
5910eb3456 Add Flag to Favor Hydration Performance over User Safety (#28655)
If false, this ignores text comparison checks during hydration at the
risk of privacy safety.

Since React 18 we recreate the DOM starting from the nearest Suspense
boundary if any of the text content mismatches. This ensures that if we
have nodes that otherwise line up correctly such as if they're the same
type of Component but in a different order, then we don't accidentally
transfer state or attributes to the wrong one.

If we didn't do this e.g. attributes like image src might not line up
with the text. E.g. you might show the wrong profile picture with the
wrong name. However, the main reason we do this is because it's a
security/privacy concern if state from the original node can transfer to
the other one. For example if you start typing into a text field to
reply to a story but then it turns out that the hydration was in a
different order, you might submit that text into a different story than
you intended. Similarly, if you've already clicked an item and that gets
replayed using Action replaying or is synchronously force hydrated -
that click might end up applying to a different item in the list than
you intended. E.g. liking the wrong photo.

Unfortunately a common case where this happens is when Google Translate
is applied to a page. It'll always cause mismatches and recreate the
tree. Most of the time this wouldn't be visible to users because it'd
just recreate to the same thing and then translate again. It can affect
metrics that trace when this hydration happened though.

Meta can use this flag to decide if they favor this perf metric over the
risk to user privacy.

This is similar to the old enableClientRenderFallbackOnTextMismatch flag
except this flag doesn't patch up the text when there's a mismatch.
Because we don't have the patching anymore. The assumption is that it is
safe to ignore the safety concern because we assume it's a match and
therefore favoring not patching it will lead to better perf.
2024-03-26 22:52:46 -04:00
Sebastian Markbåge
2ec2aaea98 Add Diffs to Hydration Warnings (#28512)
Stacked on #28502.

This builds on the mechanism in #28502 by adding a diff of everything
we've collected so far to the thrown error or logged error.

This isn't actually a longest common subsequence diff. This means that
there are certain cases that can appear confusing such as a node being
added/removed when it really would've appeared later in the list. In
fact once a node mismatches, we abort rendering so we don't have the
context of what would've been rendered. It's not quite right to use the
result of the recovery render because it can use client-only code paths
using useSyncExternalStore which would yield false differences. That's
why diffing the HTML isn't quite right.

I also present abstract components in the stack, these are presented
with the client props and no diff since we don't have the props that
were on the server. The lack of difference might be confusing but it's
useful for context.

The main thing that's data new here is that we're adding some siblings
and props for context.

Examples in the [snapshot
commit](e14532fd8d).
2024-03-26 20:02:18 -04:00
Sebastian Markbåge
f7aa5e0aa3 Move Hydration Mismatch Errors to Throw or Log Once (Kind of) (#28502)
Stacked on #28476.

We used to `console.error` for every mismatch we found, up until the
error we threw for the hydration mismatch.

This changes it so that we build up a set of diffs up until we either
throw or complete hydrating the root/suspense boundary. If we throw, we
append the diff to the error message which gets passed to
onRecoverableError (which by default is also logged to console). If we
complete, we append it to a `console.error`.

Since we early abort when something throws, it effectively means that we
can only collect multiple diffs if there were preceding non-throwing
mismatches - i.e. only properties mismatched but tag name matched.

There can still be multiple logs if multiple siblings Suspense
boundaries all error hydrating but then they're separate errors
entirely.

We still log an extra line about something erroring but I think the goal
should be that it leads to a single recoverable or console.error.

This doesn't yet actually print the diff as part of this message. That's
in a follow up PR.
2024-03-26 20:01:41 -04:00
Sebastian Markbåge
4b8dfd6215 Move Hydration Warnings from the DOM Config into the Fiber reconciliation (#28476)
Stacked on #28458.

This doesn't actually really change the messages yet, it's just a
refactor.

Hydration warnings can be presented either as HTML or React JSX format.
If presented as HTML it makes more sense to make that a DOM specific
concept, however, I think it's actually better to present it in terms of
React JSX.

Most of the time the errors aren't going to be something messing with
them at the HTML/HTTP layer. It's because the JS code does something
different. Most of the time you're working in just React. People don't
necessarily even know what the HTML form of it looks like. So this takes
the approach that the warnings are presented in React JSX in their rich
object form.

Therefore, I'm moving the approach to yield diff data to the reconciler
but it's the reconciler that's actually printing all the warnings.
2024-03-26 19:04:18 -04:00