Stacked on #33482.
There's a flaw with getting information from the execution context of
the ping. For the soft-deprecated "throw a promise" technique, this is a
bit unreliable because you could in theory throw the same one multiple
times. Similarly, a more fundamental flaw with that API is that it
doesn't allow for tracking the information of Promises that are already
synchronously able to resolve.
This stops tracking the async debug info in the case of throwing a
Promise and only when you render a Promise. That means some loss of data
but we should just warn for throwing a Promise anyway.
Instead, this also adds support for tracking `use()`d thenables and
forwarding `_debugInfo` from then. This is done by extracting the info
from the Promise after the fact instead of in the resolve so that it
only happens once at the end after the pings are done.
This also supports passing the same Promise in multiple places and
tracking the debug info at each location, even if it was already
instrumented with a synchronous value by the time of the second use.
Previously you weren't guaranteed to have only advancing time entries,
you could jump back in time, but now it omits unnecessary duplicates and
clamps automatically if you emit a previous time entry to enforce
forwards order only.
The reason I didn't do this originally is because `await` can jump in
the order because we're trying to encode a graph into a flat timeline
for simplicity of the protocol and consumers.
```js
async function a() {
await fetch1();
await fetch2();
}
async function b() {
await fetch3();
}
async function foo() {
const p = a();
await b();
return p;
}
```
This can effectively create two parallel sequences:
```
--1.................----2.......--
------3......---------------------
```
This can now be flattened to either:
```
--1.................3---2.......--
```
Or:
```
------3......1......----2.......--
```
Depending on which one we visit first. Regardless, information is lost.
I'd say that the second one is worse encoding of this scenario because
it pretends that we weren't waiting for part of the timespan that we
were. To solve this I think we should probably make `emitAsyncSequence`
create a temporary flat list and then sort it by start time before
emitting.
Although we weren't actually blocked since there was some CPU time that
was able to proceed to get to 3. So maybe the second one is actually
better. If we wanted that consistently we'd have to figure out what the
intersection was.
---------
Co-authored-by: Hendrik Liebau <mail@hendrik-liebau.de>
Includes #31412.
The issue is that `pushTreeFork` stores some global state when reconcile
children. This gets popped by `popTreeContext` in `completeWork`.
Normally `completeWork` returns its own `Fiber` again if it wants to do
a second pass which will call `pushTreeFork` again in the next pass.
However, `SuspenseList` doesn't return itself, it returns the next child
to work on.
The fix is to keep track of the count and push it again it when we
return the next child to attempt.
There are still some outstanding issues with hydration. Like the
backwards test still has the wrong behavior in it because it hydrates
backwards and so it picks up the DOM nodes in reverse order.
`tail="hidden"` also doesn't work correctly.
There's also another issue with `useId` and `AsyncIterable` in
SuspenseList when there's an unknown number of children. We don't
support those showing one at a time yet though so it's not an issue yet.
To fix it we need to add variable total count to the `useId` algorithm.
E.g. by falling back to varint encoding.
---------
Co-authored-by: Rick Hanlon <rickhanlonii@fb.com>
Co-authored-by: Ricky <rickhanlonii@gmail.com>
This adds some I/O to go get the third party thing to test how it
overlaps.
With #33482, this is what it looks like. The await gets cut off when the
third party component starts rendering. I.e. after the latency to start.
<img width="735" alt="Screenshot 2025-06-08 at 5 42 46 PM"
src="https://github.com/user-attachments/assets/f68d9a84-05a1-4125-b3f0-8f3e4eaaa5c1"
/>
This doesn't fully simulate everything because it should actually also
simulate each chunk of the stream coming back too. We could wrap the
ReadableStream to simulate that. In that scenario, it would probably get
some awaits on the chunks at the end too.
## Summary
In react-native props that are passed as function get converted to a
boolean (`true`). This is the default pattern for event handlers in
react-native.
However, there are reasons for why you might want to opt-out of this
behavior, and instead, pass along the actual function as the prop.
Right now, there is no way to do this, and props that are functions
always get set to `true`.
The `ViewConfig` attributes already have the API for a `process`
function. I simply moved the check for the process function up, so if a
ViewConfig's prop attribute configured a process function this is always
called first.
This provides an API to opt out of the default behavior.
This is the accompanied PR for react-native:
- https://github.com/facebook/react-native/pull/48777
## How did you test this change?
<!--
Demonstrate the code is solid. Example: The exact commands you ran and
their output, screenshots / videos if the pull request changes the user
interface.
How exactly did you verify that your PR solves the issue you wanted to
solve?
If you leave this empty, your PR will very likely be closed.
-->
I modified the code manually in a template react-native app and
confirmed its working. This is a code path you only need in very special
cases, thus it's a bit hard to provide a test for this. I recorded a
video where you can see that the changes are active and the prop is
being passed as native value.
For this I created a custom native component with a view config that
looked like this:
```js
const viewConfig = {
uiViewClassName: 'CustomView',
bubblingEventTypes: {},
directEventTypes: {},
validAttributes: {
nativeProp: {
process: (nativeProp) => {
// Identity function that simply returns the prop function callback
// to opt out of this prop being set to `true` as its a function
return nativeProp
},
},
},
}
```
https://github.com/user-attachments/assets/493534b2-a508-4142-a760-0b1b24419e19
Additionally I made sure that this doesn't conflict with any existing
view configs in react native. In general, this shouldn't be a breaking
change, as for existing view configs it didn't made a difference if you
simply set `myProp: true` or `myProp: { process: () => {...} }` because
as soon as it was detected that the prop is a function the config
wouldn't be used (which is what this PR fixes).
Probably everyone, including the react-native core components use
`myProp: true` for callback props, so this change should be fine.
Technically the async call graph spans basically all the way back to the
start of the app potentially, but we don't want to include everything.
Similarly we don't want to include everything from previous components
in every child component. So we need some heuristics for filtering out
data.
We roughly want to be able to inspect is what might contribute to a
Suspense loading sequence even if it didn't this time e.g. due to a race
condition.
One flaw with the previous approach was that awaiting a cached promise
in a sibling that happened to finish after another sibling would be
excluded. However, in a different race condition that might end up being
used so I wanted to include an empty "await" in that scenario to have
some association from that component.
However, for data that resolved fully before the request even started,
it's a little different. This can be things that are part of the start
up sequence of the app or externally cached data. We decided that this
should be excluded because it doesn't contribute to the loading sequence
in the expected scenario. I.e. if it's cached. Things that end up being
cache misses would still be included. If you want to test externally
cached data misses, then it's up to you or the framework to simulate
those. E.g. by dropping the cache. This also helps free up some noise
since static / cached data can be excluded in visualizations.
I also apply this principle to forwarding debug info. If you reuse a
cached RSC payload, then the Server Component render time and its awaits
gets clamped to the caller as if it has zero render/await time. The I/O
entry is still back dated but if it was fully resolved before we started
then it's completely excluded.
I noticed that the ThirdPartyComponent in the fixture was showing the
wrong stack and the `"use third-party"` is in the wrong location.
<img width="628" alt="Screenshot 2025-06-06 at 11 22 11 PM"
src="https://github.com/user-attachments/assets/f0013380-d79e-4765-b371-87fd61b3056b"
/>
When creating the initial JSX inside the third party server, we should
make sure that it has no owner. In a real cross-server environment you
get this by default by just executing in different context. But since
the fixture example is inside the same AsyncLocalStorage as the parent
it already has an owner which gets transferred. So we should make sure
that were we create the JSX has no owner to simulate this.
When we then parse a null owner on the receiving side, we replace its
owner/stack with the owner/stack of the call to `createFrom...` to
connect them. This worked fine with only two environments. The bug was
that when we did this and then transferred the result to a third
environment we took the original parsed stack trace. We should instead
parse a new one from the replaced stack in the current environment.
The second bug was that the `"use third-party"` badge ends up in the
wrong place when we do this kind of thing. Because the stack of the
thing entering the new environment is the call to `createFrom...` which
is in the old environment even though the component itself executes in
the new environment. So to see if there's a change we should be
comparing the current environment of the task to the owner's environment
instead of the next environment after the task.
After:
<img width="494" alt="Screenshot 2025-06-07 at 1 13 28 AM"
src="https://github.com/user-attachments/assets/e2e870ba-f125-4526-a853-bd29f164cf09"
/>
This effectively lets us consume Web Streams in a Node build. In fact
the Node entry point is now just adding Node stream APIs.
For the client, this is simple because the configs are not actually
stream type specific. The server is a little trickier.
Reverts #33457, #33456 and #33442.
There are too many issues with wrappers, lazy init, stateful modules,
duplicate instantiation of async_hooks and duplication of code.
Instead, we'll just do a wrapper polyfill that uses Node Streams
internally.
I kept the client indirection files that I added for consistency with
the server though.
When deeply nested Suspense boundaries inside a fallback of another
boundary resolve it is possible to encounter situations where you either
attempt to flush an aborted Segment or you have a boundary without any
root segment. We intended for both of these conditions to be impossible
to arrive at legitimately however it turns out in this situation you
can. The fix is two-fold
1. allow flushing aborted segments by simply skipping them. This does
remove some protection against future misconfiguraiton of React because
it is no longer an invariant that you hsould never attempt to flush an
aborted segment but there are legitimate cases where this can come up
and simply omitting the segment is fine b/c we know that the user will
never observe this. A semantically better solution would be to avoid
flushing boudaries inside an unneeded fallback but to do this we would
need to track all boundaries inside a fallback or create back pointers
which add to memory overhead and possibly make GC harder to do
efficiently. By flushing extra we're maintaining status quo and only
suffer in performance not with broken semantics.
2. when queuing completed segments allow for queueing aborted segments
and if we are eliding the enqueued segment allow for child segments that
are errored to be enqueued too. This will mean that we can maintain the
invariant that a boundary must have a root segment the first time we
flush it, it just might be aborted (see point 1 above).
This change has two seemingly similar test cases to exercise this fix.
The reason we need both is that when you have empty segments you hit
different code paths within Fizz and so each one (without this fix)
triggers a different error pathway.
This change also includes a fix to our tests where we were not
appropriately setting CSPnonce back to null at the start of each test so
in some contexts scripts would not run for some tests
Adding throttling or delaying on images, can obviously impact metrics.
However, it's all in the name of better actual user experience overall.
(Note that it's not strictly worse even for metric. Often it's actually
strictly better due to less work being done overall thanks to batching.)
Metrics can impact things like search ranking but I believe this is on a
curve. If you're already pretty good, then a slight delay won't suddenly
make you rank in a completely different category. Similarly, if you're
already pretty bad then a slight delay won't make it suddenly way worse.
It's still in the same realm. It's just one weight of many. I don't
think this will make a meaningful practical impact and if it does,
that's probably a bug in the weights that will get fixed.
However, because there's a race to try to "make everything green" in
terms of web vitals, if you go from green to yellow only because of some
throttling or suspensey images, it can feel bad. Therefore this
implements a heuristic where if the only reason we'd miss a specific
target is because of throttling or suspensey images, then we shorten the
timeout to hit the metric. This is a worse user experience because it
can lead to extra flashing but feeling good about "green" matters too.
If you then have another reveal that happens to be the largest
contentful paint after that, then that's throttled again so that it
doesn't become flashy after that. If you've already missed the deadline
then you're not going to hit your metric target anyway. It can affect
average but not median.
This is mainly about LCP. It doesn't affect FCP since that doesn't have
a throttle. If your LCP is the same as your FCP then it also doesn't
matter.
We assume that `performance.now()`'s zero point starts at the "start of
the navigation" which makes this simple. Even if we used the
`PerformanceNavigationTiming` API it would just tell us the same thing.
This only implements for Fizz since these metrics tend to currently only
by tracked for initial loads, but with soft navs tracking we could
consider implementing the same for Fiber throttles.
Follow up to #33442. This is the bundled version.
To keep type check passes from exploding and the maintainance of the
annoying `paths: []` list small, this doesn't add this to flow type
checks. We might miss some config but every combination should already
be covered by other one passes.
I also don't add any jest tests because to test these double export
entry points we need conditional importing to cover builds and
non-builds which turns out to be difficult for the Flight builds so
these aren't covered by any basic build tests.
This approach is what I'm going for, for the other bundlers too.
We want to make sure that we can block the reveal of a well designed
complete shell reliably. In the Suspense model, client transitions don't
have any way to implicitly resolve. This means you need to use Suspense
or SuspenseList to explicitly split the document. Relying on implicit
would mean you can't add a Suspense boundary later where needed. So we
highly encourage the use of them around large content.
However, if you have constructed a too large shell (e.g. by not adding
any Suspense boundaries at all) then that might take too long to render
on the client. We shouldn't punish users (or overzealous metrics
tracking tools like search engines) in that scenario.
This opts out of render blocking if the shell ends up too large to be
intentional and too slow to load. Instead it deopts to showing the
content split up in arbitrary ways (browser default). It only does this
for SSR, and not client navs so it's not reliable.
In fact, we issue an error to `onError`. This error is recoverable in
that the document is still produced. It's up to your framework to decide
if this errors the build or just surface it for action later.
What should be the limit though? There's a trade off here. If this limit
is too low then you can't fit a reasonably well built UI within it
without getting errors. If it's too high then things that accidentally
fall below it might take too long to load.
I came up with 512kB of uncompressed shell HTML. See the comment in code
for the rationale for this number. TL;DR: Data and theory indicates that
having this much content inside `rel="expect"` doesn't meaningfully
change metrics. Research of above-the-fold content on various websites
indicate that this can comfortable fit all of them which should be
enough for any intentional initial paint.
Block the view transition on suspensey images Up to 500ms just like the
client.
We can't use `decode()` because a bug in Chrome where those are blocked
on `startViewTransition` finishing we instead rely on sync decoding but
also that the image is live when it's animating in and we assume it
doesn't start visible.
However, we can block the View Transition from starting on the `"load"`
or `"error"` events.
The nice thing about blocking inside `startViewTransition` is that we
have already done the layout so we can only wait on images that are
within the viewport at this point. We might want to do that in Fiber
too. If many image doesn't have fixed size but need to load first, they
can all end up in the viewport. We might consider only doing this for
images that have a fixed size or only a max number that doesn't have a
fixed size.
## Summary
Enables the `enableEagerAlternateStateNodeCleanup` feature flag for all
variants, while maintaining the `__VARIANT__` for the internal React
Native flavor for backtesting reasons.
## How did you test this change?
```
$ yarn test
```
When I added the `ready_for_review` event in #32344, no notifications
for opened draft PRs were sent due to some other condition. This is not
the case anymore, so we need to exclude draft PRs from triggering a
notification when the workflow is run because of an `opened` event. This
event is still needed because the `ready_for_review` event only fires
when an existing draft PR is converted to a non-draft state. It does not
trigger for pull requests that are opened directly as ready-for-review.
We highly recommend using Node Streams in Node.js because it's much
faster and it is less likely to cause issues when chained in things like
compression algorithms that need explicit flushing which the Web Streams
ecosystem doesn't have a good solution for. However, that said, people
want to be able to use the worse option for various reasons.
The `.edge` builds aren't technically intended for Node.js. A Node.js
environments needs to be patched in various ways to support it. It's
also less optimal since it can't use [Node.js exclusive
features](https://github.com/facebook/react/pull/33388) and have to use
[the lowest common
denominator](https://github.com/facebook/react/pull/27399) such as JS
implementations instead of native.
This adds a Web Streams build of Fizz but exclusively for Node.js so
that in it we can rely on Node.js modules. The main difference compared
to Edge is that SSR now uses `createHash` from the `"crypto"` module and
imports `TextEncoder` from `"util"`. We use `setImmediate` instead of
`setTimeout`.
The public API is just `react-dom/server` which in Node.js automatically
imports `react-dom/server.node` which re-exports the legacy bundle, Node
Streams bundle and Node Web Streams bundle. The main downside is if your
bundler isn't smart to DCE this barrel file.
With Flight the difference is larger but that's a bigger lift.
Stacked on #33403.
When a Promise is coming from React such as when it's passed from
another environment, we should forward the debug information from that
environment. We already do that when rendered as a child.
This makes it possible to also `await promise` and have the information
from that instrumented promise carry through to the next render.
This is a bit tricky because the current protocol is that we have to
read it from the Promise after it resolves so it has time to be assigned
to the promise. `async_hooks` doesn't pass us the instance (even though
it has it) when it gets resolved so we need to keep it around. However,
we have to be very careful because if we get this wrong it'll cause a
memory leak since we retain things by `asyncId` and then manually listen
for `destroy()` which can only be called once a Promise is GC:ed, which
it can't be if we retain it. We have to therefore use a `WeakRef` in
case it never resolves, and then read the `_debugInfo` when it resolves.
We could maybe install a setter or something instead but that's also
heavy.
The other issues is that we don't use native Promises in
ReactFlightClient so our instrumented promises aren't picked up by the
`async_hooks` implementation and so we never get a handle to our
thenable instance. To solve this we can create a native wrapper only in
DEV.
We want to change the defaults for `revealOrder` and `tail` on
SuspenseList. This is an intermediate step to allow experimental users
to upgrade.
To explicitly specify these options I added `revealOrder="independent"`
and `tail="visible"`.
I then added warnings if `undefined` or `null` is passed. You must now
always explicitly specify them. However, semantics are still preserved
for now until the next step.
We also want to change the rendering order of the `children` prop for
`revealOrder="backwards"`. As an intermediate step I first added
`revealOrder="unstable_legacy-backwards"` option. This will only be
temporary until all users can switch to the new `"backwards"` semantics
once we flip it in the next step.
I also clarified the types that the directional props requires iterable
children but not iterable inside of those. Rows with multiple items can
be modeled as explicit fragments.
Stacked on #33402.
There's a bug in Chrome Performance tracking which uses the enclosing
line/column instead of the callsite in stacks.
For our fake eval:ed functions that represents functions on the server,
we can position the enclosing function body at the position of the
callsite to simulate getting the right line.
Unfortunately, that doesn't give us exactly the right callsite when it's
used for other purposes that uses the callsite like console logs and
error reporting and stacks inside breakpoints. So I don't think we want
to always do this.
For ReactAsyncInfo/ReactIOInfo, the only thing we're going to use the
fake task for is the Performance tracking, so it doesn't have any
downsides until Chrome fixes the bug and we'd have to revert it.
Therefore this PR uses that techniques only for those entries.
We could do this for Server Components too but we're going to use those
for other things too like console logs. I don't think it's worth
duplicating the Task objects. That would also make it inconsistent with
Client Components.
For Client Components, we could in theory also generate fake evals but
that would be way slower since there's so many of them and currently we
rely on the native implementation for those. So doesn't seem worth
fixing.
But since we can at least fix it for RSC I/O/awaits we can do this hack.
Stacked on #33400.
<img width="1261" alt="Screenshot 2025-06-01 at 10 27 47 PM"
src="https://github.com/user-attachments/assets/a5a73ee2-49e0-4851-84ac-e0df6032efb5"
/>
This is emitted with the start/end time and stack of the "await". Which
may be different than the thing that started the I/O.
These awaits aren't quite as simple as just every await since you can
start a sequence in parallel there can actually be multiple overlapping
awaits and there can be CPU work interleaved with the await on the same
component.
```js
function getData() {
await fetch(...);
await fetch(...);
}
const promise = getData();
doWork();
await promise;
```
This has two "I/O" awaits but those are actually happening in parallel
with `doWork()`.
Since these also could have started before we started rendering this
sequence (e.g. a component) we have to clamp it so that we don't
consider awaits that start before the component.
What we're conceptually trying to convey is the time this component was
blocked due to that I/O resource. Whether it's blocked from completing
the last result or if it's blocked from issuing a waterfall request.
Stacked on #33395.
This lets us keep track of which environment this was fetched and
awaited.
Currently the IO and await is in the same environment. It's just kept
when forwarded. Once we support forwarding information from a Promise
fetched from another environment and awaited in this environment then
the await can end up being in a different environment.
There's a question of when the await is inside Flight itself such as
when you return a promise fetched from another environment whether that
should mean that the await is in the current environment. I don't think
so since the original stack trace is the best stack trace. It's only if
you `await` it in user space in this environment first that this might
happen and even then it should only be considered if there wasn't a
better await earlier or if reading from the other environment was itself
I/O.
The timing of *when* we read `environmentName()` is a little interesting
here too.
Stacked on #33394.
This lets us create async stack traces to the owner that was in context
when the I/O was started or awaited.
<img width="615" alt="Screenshot 2025-06-01 at 12 31 52 AM"
src="https://github.com/user-attachments/assets/6ff5a146-33d6-4a4b-84af-1b57e73047d4"
/>
This owner might not be the immediate closest parent where the I/O was
awaited.
Stacked on #33392.
This adds another track to the Performance Track called `"Server
Requests"`.
<img width="1015" alt="Screenshot 2025-06-01 at 12 02 14 AM"
src="https://github.com/user-attachments/assets/c4d164c4-cfdf-4e14-9a87-3f011f65fd20"
/>
This logs the flat list of I/O awaited on by Server Components. There
will be other views that are more focused on what data blocks a specific
Component or Suspense boundary but this is just the list of all the I/O
basically so you can get an overview of those waterfalls without the
noise of all the Component trees and rendering. It's similar to what the
"Network" track is on the client.
I've been going back and forth on what to call this track but I went
with `"Server Requests"` for now. The idea is that the name should
communicate that this is something that happens on the server and is a
pairing with the `"Server Components"` track. Although we don't use that
feature, since it's missing granularity, it's also similar to "Server
Timings".
Stacked on #33390.
The stack trace doesn't include the thing you called when calling into
ignore listed content. We consider the ignore listed content
conceptually the abstraction that you called that's interesting.
This extracts the name of the first ignore listed function that was
called from user space. For example `"fetch"`. So we can know what kind
of request this is.
This could be enhanced and tweaked with heuristics in the future. For
example, when you create a Promise yourself and call I/O inside of it
like my `delay` examples, then we use that Promise as the I/O node but
its stack doesn't have the actual I/O performed. It might be better to
use the inner I/O node in that case. E.g. `setTimeout`. Currently I pick
the name from the first party code instead - in my example `delay`.
Another case that could be improved is the case where your whole
component is third-party. In that case we still log the I/O but it has
no context about what kind of I/O since the whole stack is ignored it
just gets the component name for example. We could for example look at
the first name that is in a different package than the package name of
the ignored listed component. So if
`node_modules/my-component-library/index.js` calls into
`node_modules/mysql/connection.js` then we could use the name from the
inner.
Stacked on #33388.
This encodes the I/O entries as their own row type (`"J"`). This makes
it possible to parse them directly without first parsing the debug info
for each component. E.g. if you're just interested in logging the I/O
without all the places it was awaited.
This is not strictly necessary since the debug info is also readily
available without parsing the actual trees. (That's how the Server
Components Performance Track works.) However, we might want to exclude
this information in profiling builds while retaining some limited form
of I/O tracking.
It also allows for logging side-effects that are not awaited if we
wanted to.
This lets us track what data each Server Component depended on. This
will be used by Performance Track and React DevTools.
We use Node.js `async_hooks`. This has a number of downside. It is
Node.js specific so this feature is not available in other runtimes
until something equivalent becomes available. It's [discouraged by
Node.js docs](https://nodejs.org/api/async_hooks.html#async-hooks). It's
also slow which makes this approach only really viable in development
mode. At least with stack traces. However, it's really the only solution
that gives us the data that we need.
The [Diagnostic
Channel](https://nodejs.org/api/diagnostics_channel.html) API is not
sufficient. Not only is many Node.js built-in APIs missing but all
libraries like databases are also missing. Were as `async_hooks` covers
pretty much anything async in the Node.js ecosystem.
However, even if coverage was wider it's not actually showing the
information we want. It's not enough to show the low level I/O that is
happening because that doesn't provide the context. We need the stack
trace in user space code where it was initiated and where it was
awaited. It's also not each low level socket operation that we want to
surface but some higher level concept which can span a sequence of I/O
operations but as far as user space is concerned.
Therefore this solution is anchored on stack traces and ignore listing
to determine what the interesting span is. It is somewhat
Promise-centric (and in particular async/await) because it allows us to
model an abstract span instead of just random I/O. Async/await points
are also especially useful because this allows Async Stacks to show the
full sequence which is not supported by random callbacks. However, if no
Promises are involved we still to our best to show the stack causing
plain I/O callbacks.
Additionally, we don't want to track all possible I/O. For example,
side-effects like logging that doesn't affect the rendering performance
doesn't need to be included. We only want to include things that
actually block the rendering output. We also need to track which data
blocks each component so that we can track which data caused a
particular subtree to suspend.
We can do this using `async_hooks` because we can track the graph of
what resolved what and then spawned what.
To track what suspended what, something has to resolve. Therefore it
needs to run to completion before we can show what it was suspended on.
So something that never resolves, won't be tracked for example.
We use the `async_hooks` in `ReactFlightServerConfigDebugNode` to build
up an `ReactFlightAsyncSequence` graph that collects the stack traces
for basically all I/O and Promises allocated in the whole app. This is
pretty heavy, especially the stack traces, but it's because we don't
know which ones we'll need until they resolve. We don't materialize the
stacks until we need them though.
Once they end up pinging the Flight runtime, we collect which current
executing task that pinged the runtime and then log the sequence that
led up until that runtime into the RSC protocol. Currently we only
include things that weren't already resolved before we started rendering
this task/component, so that we don't log the entire history each time.
Each operation is split into two parts. First a `ReactIOInfo` which
represents an I/O operation and its start/end time. Basically the start
point where it was start. This is basically represents where you called
`new Promise()` or when entering an `async function` which has an
implied Promise. It can be started in a different component than where
it's awaited and it can be awaited in multiple places. Therefore this is
global information and not associated with a specific Component.
The second part is `ReactAsyncInfo`. This represents where this I/O was
`await`:ed or `.then()` called. This is associated with a point in the
tree (usually the Promise that's a direct child of a Component). Since
you can have multiple different I/O awaited in a sequence technically it
forms a dependency graph but to simplify the model these awaits as
flattened into the `ReactDebugInfo` list. Basically it contains each
await in a sequence that affected this part from unblocking.
This means that the same `ReactAsyncInfo` can appear in mutliple
components if they all await the same `ReactIOInfo` but the same Promise
only appears once.
Promises that are only resolved by other Promises or immediately are not
considered here. Only if they're resolved by an I/O operation. We pick
the Promise basically on the border between user space code and ignored
listed code (`node_modules`) to pick the most specific span but abstract
enough to not give too much detail irrelevant to the current audience.
Similarly, the deepest `await` in user space is marked as the relevant
`await` point.
This feature is only available in the `node` builds of React. Not if you
use the `edge` builds inside of Node.js.
---------
Co-authored-by: Sebastian "Sebbie" Silbermann <silbermann.sebastian@gmail.com>
Alternative to #33421. The difference is that this also adds an
underscore between the "R" and the ID.
The reason we wanted to use special characters is because we use the
full spectrum of A-Z 0-9 in our ID generation so we can basically
collide with any common word (or anyone using a similar algorithm,
base64 or even base16). It's a little less likely that someone would put
`_R_` specifically unless you generate like two IDs separated by
underscore.

## Summary
This tool leverages DevTools to get the component tree from the
currently open React App. This gives realtime information to agents
about the state of the app.
## How did you test this change?
Tested integration with Claude Desktop
This is a babel bug + edge case.
Babel compact mode produces invalid JavaScript (i.e. parse error) when
given a `NumericLiteral` with a negative value.
See https://codesandbox.io/p/devbox/5d47fr for repro.
## Summary
While investigating the root cause of #33208, I noticed a clear typo for
one of the validation files.
## How did you test this change?
Inside `/react/compiler/packages/babel-plugin-react-compiler` I ran the
test script successfully:
<img width="415" alt="Screenshot at May 22 16-43-06"
src="https://github.com/user-attachments/assets/3fe8c5e1-37ce-4a31-b35e-7e323e57cd9d"
/>
## Summary
We completed testing on these internally, so can cleanup the separate
fast and slow paths and remove the `enableShallowPropDiffing` flag which
we're not pursuing.
## How did you test this change?
```
yarn test ReactNativeAttributePayloadFabric
```
fixes https://github.com/facebook/react/issues/32449
This is my first time touching this code. There are multiple systems in
place here and I wouldn't be surprised to learn that this has to be
handled in some other areas too. I have found some other style-related
code areas but I had no time yet to double-check them.
cc @gnoff
This is the same technique we do for the client except we don't check
whether this is newly created font loading to keep code small.
Unfortunately, we can't use this technique for Suspensey images. They'll
need to block before we call `startViewTransition` in a separate
refactor. This is due to a bug in Chrome where `img.decode()` doesn't
resolve until `startViewTransition` does.
There seems to be some bugs still to work out in Chrome. See #33187.
Additionally, since you can't really rely on this function existing
across browsers, it's hard to depend on its behavior anyway. In fact,
you now have a source of inconsistent behaviors across browsers to deal
with.
Ideally it would also be more widely spread in fake DOM implementations
like JSDOM so that we can use it unconditionally. #33177.
We still want to enable this since it's a great feature but maybe not
until it's more widely available cross-browsers with fewer bugs.
Summary:
To prepare for automatic effect dependencies, some codebases may want to
codemod
existing useEffect calls with no deps to include an explicit undefined
second argument
in order to preserve the "run on every render" behavior. In sufficiently
large codebases,
this may require a temporary enforcement period where all effects
provide an explicit
dependencies argument.
Outside of migration, relying on a component to render can lead to real
bugs,
especially when working with memoization.
## Summary
This PR fixes a likely incorrect condition in the
`scheduleUpdateOnFiber` function inside `ReactFiberWorkLoop.js`.
Previously, the code checked:
```js
(executionContext & RenderContext) !== NoLanes
````
However, `NoLanes` is part of the lane priority system, not the
execution context flags. The intent here seems to be to detect whether
the current execution context includes `RenderContext`, which should be
compared against `NoContext`, not `NoLanes`.
This fix replaces `NoLanes` with `NoContext` for semantic correctness
and consistency with other checks throughout the codebase.
**Fixes
[[#33169](https://github.com/facebook/react/issues/33169)](https://github.com/facebook/react/issues/33169)**
---
## How did you test this change?
I ran the following commands to validate correctness and ensure nothing
was broken:
* `yarn lint`
* `yarn linc`
* `yarn test`
* `yarn test --prod`
* `yarn flow`
* `yarn prettier`
All checks passed. Since this is a minor internal logic fix and doesn't
change public behavior or APIs, no additional tests are necessary at
this time.
## Summary
I am writing code that isn't so good, so I saw this error message many
times. It appears to have a typo. This PR fixes the typo.
## How did you test this change?
Ran the tests
Inferred effect dependencies now include optional chains.
This is a temporary solution while
https://github.com/facebook/react/pull/32099 and its followups are
worked on. Ideally, we should model reactive scope dependencies in the
IR similarly to `ComputeIR` -- dependencies should be hoisted and all
references rewritten to use the hoisted dependencies.
`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33326).
* __->__ #33326
* #33325
* #32286
Stacked on #33330.
This walks the element tree to activate the various classes under
different scenarios. There are some edge case things that are a little
different since we can't express every scenario without virtual nodes.
The main thing that's still missing though is avoiding animating updates
if it can be contained to a layout or enter/exit/share if they're out of
the viewport. I.e. layout stuff.
Follow up to #33293.
This solves a race condition when boundaries are added to the batch
after the `startViewTransition` call.
This doesn't matter yet but it will once we start assigning names before
the `startViewTransition` call.
A possible alternative solution might be to ensure the names are added
synchronously in the event that adds to the batch. It's possible to keep
adding to a batch until the snapshot has happened.
I believe that these mean the same thing. We don't have to emit the
attribute if it's `none` for these cases because if there is no matching
scenario we won't apply the animation in this case.
The only case where we have to emit `none` in the attribute is for
`vt-update` because those can block updates from propagating upwards.
Follow up to #33321.
We can mark boundaries that were blocked in the prerender as postponed
but without anything to replayed inside them. That way they're not
emitted in the prerender but is unblocked when replayed.
Technically this does some unnecessary replaying of the path to the
otherwise already completed boundary but it simplifies our model by just
marking the boundary as needing replaying.
This uses the richer `serverAct` helper that we already use in other
tests.
This avoids using the `Scheduler`. We don't use that package on the
server so it doesn't make sense to simulate going through it.
Additionally, we really should be getting rid of it on the client too to
favor `postTask` polyfills.
When a new child of a fragment instance is inserted, we need to notify
the instance to keep any relevant tracking up to date. For example, we
automatically observe the new child with any active
IntersectionObserver.
For mutable renderers (DOM), we reuse the existing traversal in
`commitPlacement` that does the insertions for HostComponents. Immutable
renderers (Fabric) exit this path before the traversal though, so
currently we can't notify the fragment instances.
Here I've created a separate traversal in `commitPlacement`,
specifically for immutable renders when `enableFragmentRefs` is on.
There's an interesting case when a SuspenseList is partially prerendered
but some of the completed boundaries are blocked by rows to be resumed.
This handles it but just unblocking the future rows to avoid stalling.
However, the correct semantics will need special handling in the
postponed state.
We have many cases internally where the `containerInstance` resolves to
a comment node. `restoreRootViewTransitionName` is called when
`enableViewTransition` is on, even without introducing a
`<ViewTransition />`. So that means it can crash pages because
`containerInstance.style` is `undefined` just by turning on the flag.
This skips cancel/restore of root view transition name if a comment node is the root.
I missed setting the `keyPath` because the `renderChildrenArray` that
this is forked from doesn't need to set a path but since this is
rendered from the `SuspenseList` element it needs it.
Stacked on #33311.
When a row contains Suspense boundaries that themselves depend on CSS,
they will not resolve until the CSS has loaded on the client. We need
future rows in a list to be blocked until this happens. We could do
something in the runtime but a simpler approach is to just add those CSS
dependencies to all those boundaries as well.
To do this, we first hoist the HoistableState from a completed boundary
onto its parent row. Then when the row finishes do we hoist it onto the
next row and onto any boundaries within that row.
Stacked on #33308.
For "together" mode, we can be a self-blocking row that adds all its
boundaries to the blocked set, but there's no parent row that unblocks
it.
A particular quirk of this mode is that it's not enough to just unblock
them all on the server together. Because if one boundary downloads all
its html and then issues a complete instruction it'll appear before the
others while streaming in. What we actually want is to reveal them all
in a single batch.
This implementation takes a short cut by unblocking the rows in
`flushPartialBoundary`. That ensures that all the segments of every
boundary has a chance to flush before we start emitting any of the
complete boundary instructions. Once the last one unblocks, all the
complete boundary instructions are queued. Ideally this would be a
single `<script>` tag so that they can't be split up even if we get a
chunk containing some of them.
~A downside of this approach is that we always outline these boundaries.
We could inline them if they all complete before the parent flushes.
E.g. by checking if the row is blocked only by its own boundaries and if
all the boundaries would fit without getting outlined, then we can
inline them all at once.~ I went ahead and did this because it solves an
issue with `renderToString` where it doesn't support the script runtime
so it can only handle this if inlined.
Follow up to #33306.
If we're nested inside a SuspenseList and we have a row, then we can
point our last row to block the parent row and unblock the parent when
the last child unblocks.
We support AsyncIterable (more so when it's a cached form like in coming
from Flight) as children.
This fixes some warnings and bugs when passed to SuspenseList.
Ideally SuspenseList with `tail="hidden"` should support unblocking
before the full result has resolved but that's an optimization on top.
We also might want to change semantics for this for
`revealOrder="backwards"` so it becomes possible to stream items in
reverse order.
Basically we track a `SuspenseListRow` on the task. These keep track of
"pending tasks" that block the row. A row is blocked by:
- First itself completing rendering.
- A previous row completing.
- Any tasks inside the row and before the Suspense boundary inside the
row. This is mainly because we don't yet know if we'll discover more
SuspenseBoundaries.
- Previous row's SuspenseBoundaries completing.
If a boundary might get outlined, then we can't consider it completed
until we have written it because it determined whether other future
boundaries in the row can finish.
This is just handling basic semantics. Features not supported yet that
need follow ups later:
- CSS dependencies of previous rows should be added as dependencies of
future row's suspense boundary. Because otherwise if the client is
blocked on CSS then a previous row could be blocked but the server
doesn't know it.
- I need a second pass on nested SuspenseList semantics.
- `revealOrder="together"`
- `tail="hidden"`/`tail="collapsed"`. This needs some new runtime
semantics to the Fizz runtime and to allow the hydration to handle
missing rows in the HTML. This should also be future compatible with
AsyncIterable where we don't know how many rows upfront.
- Need to double check resuming semantics.
---------
Co-authored-by: Sebastian "Sebbie" Silbermann <silbermann.sebastian@gmail.com>
When needed.
For the external runtime we always include this wrapper.
For others, we only include it if we have an ViewTransitions affecting.
If we discover the ViewTransitions late, then we can upgrade an already
emitted instruction.
This doesn't yet do anything useful with it, that's coming in a follow
up. This is just the mechanism for how it gets installed.
We decremented `allPendingTasks` after invoking `onShellReady`. Which
means that in that scope it wasn't considered fully complete.
Since the pattern for flushing in Node.js is to start piping in
`onShellReady` and that's how you can get sync behavior, this led us to
think that we had more work left to do. For example we emitted the
`writeShellTimeInstruction` in this scenario before.
Stacked on #33194 and #33200.
When Suspense boundaries reveal during streaming, the Fizz runtime will
be responsible for animating the reveal if necessary (not in this PR).
However, for the future runtime to know what to do it needs to know
about the `<ViewTransition>` configuration to apply.
Ofc, these are virtual nodes that disappear from the HTML. We could
model them as comments like we do with other virtual nodes like Suspense
and Activity. However, that doesn't let us target them with
querySelector and CSS (for no-JS transitions). We also don't have to
model every ViewTransition since not every combination can happen using
only the server runtime. So instead this collapses `<ViewTransition>`
and applies the configuration to the inner DOM nodes.
```js
<ViewTransition name="hi">
<div />
<div />
</ViewTransition>
```
Becomes:
```html
<div vt-name="hi" vt-update="auto"></div>
<div vt-name="hi_1" vt-update="auto"></div>
```
I use `vt-` prefix as opposed to `data-` to keep these virtual
attributes away from user specific ones but we're effectively claiming
this namespace.
There are four triggers `vt-update`, `vt-enter`, `vt-exit` and
`vt-share`. The server resolves which ones might apply to this DOM node.
The value represents the class name (after resolving
view-transition-type mappings) or `"auto"` if no specific class name is
needed but this is still a trigger.
The value can also be `"none"`. This is different from missing because
for example an `vt-update="none"` will block mutations inside it from
triggering the boundary where as a missing `vt-update` would bubble up
to be handled by a parent.
`vt-name` is technically only necessary when `vt-share` is specified to
find a pair. However, since an explicit name can also be used to target
specific CSS selectors, we include it even for other cases.
We want to exclude as many of these annotations as possible.
`vt-enter` can only affect the first DOM node inside a Suspense
boundary's content since the reveal would cause it to enter but nothing
deeper inside. Similarly `vt-exit` can only affect the first DOM node
inside a fallback. So for every other case we can exclude them. (For
future MPA ViewTransitions of the whole document it might also be
something we annotate to children inside the `<body>` as well.) Ideally
we'd only include `vt-enter` for Suspense boundaries that actually
flushed a fallback but since we prepare all that content earlier it's
hard to know.
`vt-share` can be anywhere inside an fallback or content. Technically we
don't have to include it outside the root most Suspense boundary or for
boundaries that are inlined into the root shell. However, this is tricky
to detect. It would also not be correct for future MPA ViewTransitions
because in that case the shared scenario can affect anything in the two
documents so it needs to be in every node everywhere which is
effectively what we do. If a `share` class is specified but it has no
explicit name, we can exclude it since it can't match anything.
`vt-update` is only necessary if something below or a sibling might
update like a Suspense boundary. However, since we don't know when
rendering a segment if it'll later asynchronously add a Suspense
boundary later we have to assume that anywhere might have a child. So
these are always included. We collapse to use the inner most one when
directly nested though since that's the one that ends up winning.
There are some weird edge cases that can't be fully modeled by the lack
of virtual nodes.
Removes the `isFallback` flag on Tasks and tracks it on the
formatContext instead.
Less memory and avoids passing and tracking extra arguments to all the
pushStartInstance branches that doesn't need it.
We'll need to be able to track more Suspense related contexts on this
for View Transitions anyway.
This is a partial revert of #33094. It's true that we don't need the
server and client ViewTransition names to line up. However the server
does need to be able to generate deterministic names for itself. The
cheapest way to do that is using the useId algorithm. When it's used by
the server, the client needs to also materialize an ID even if it
doesn't use it.
And that doesn't disable with `update="none"`.
The principle here is that we want the content of a Portal to animate if
other things are animating with it but if other things aren't animating
then we don't.
Stacked on #33160, #33162, #33186 and #33188.
We have a special case that's awkward for default indicators. When you
start a new async Transition from `React.startTransition` then there's
not yet any associated root with the Transition because you haven't
necessarily `setState` on anything yet until the promise resolves.
That's what `entangleAsyncAction` handles by creating a lane that
everything entangles with until all async actions are done.
If there are no sync updates before the end of the event, we should
trigger a default indicator until either the async action completes
without update or if it gets entangled with some roots we should keep it
going until those roots are done.
Stacked on #33160.
By default, if `onDefaultTransitionIndicator` is not overridden, this
will trigger a fake Navigation event using the Navigation API. This is
intercepted to create an on-going navigation until we complete the
Transition. Basically each default Transition is simulated as a
Navigation.
This triggers the native browser loading state (in Chrome at least). So
now by default the browser spinner spins during a Transition if no other
loading state is provided. Firefox and Safari hasn't shipped Navigation
API yet and even in the flag Safari has, it doesn't actually trigger the
native loading state.
To ensures that you can still use other Navigations concurrently, we
don't start our fake Navigation if there's one on-going already.
Similarly if our fake Navigation gets interrupted by another. We wait
for on-going ones to finish and then start a new fake one if we're
supposed to be still pending.
There might be other routers on the page that might listen to intercept
Navigation Events. Typically you'd expect them not to trigger a refetch
when navigating to the same state. However, if they want to detect this
we provide the `"react-transition"` string in the `info` field for this
purpose.
Stacked on #33160.
The purpose of this is to avoid calling `onDefaultTransitionIndicator`
when a Default priority update acts as the loading indicator, but still
call it when unrelated Default updates happens nearby.
When we schedule Default priority work that gets batched with other
events in the same frame more or less. This helps optimize by doing less
work. However, that batching means that we can't separate work from one
setState from another. If we would consider all Default priority work in
a frame when determining whether to show the default we might never show
it in cases like when you have a recurring timer updating something.
This instead flushes the Default priority work eagerly along with the
sync work at the end of the event, if this event scheduled any
Transition work. This is then used to determine if the default indicator
needs to be shown.
Stacked on #33159.
This implements `onDefaultTransitionIndicator`.
The sequence is:
1) In `markRootUpdated` we schedule Transition updates as needing
`indicatorLanes` on the root. This tracks the lanes that currently need
an indicator to either start or remain going until this lane commits.
2) Track mutations during any commit. We use the same hook that view
transitions use here but instead of tracking it just per view transition
scope, we also track a global boolean for the whole root.
3) If a sync/default commit had any mutations, then we clear the
indicator lane for the `currentEventTransitionLane`. This requires that
the lane is still active while we do these commits. See #33159. In other
words, a sync update gets associated with the current transition and it
is assumed to be rendering the loading state for that corresponding
transition so we don't need a default indicator for this lane.
4) At the end of `processRootScheduleInMicrotask`, right before we're
about to enter a new "event transition lane" scope, it is no longer
possible to render any more loading states for the current transition
lane. That's when we invoke `onDefaultTransitionIndicator` for any roots
that have new indicator lanes.
5) When we commit, we remove the finished lanes from `indicatorLanes`
and once that reaches zero again, then we can clean up the default
indicator. This approach means that you can start multiple different
transitions while an indicator is still going but it won't stop/restart
each time. Instead, it'll wait until all are done before stopping.
Follow ups:
- [x] Default updates are currently not enough to cancel because those
aren't flush in the same microtask. That's unfortunate. #33186
- [x] Handle async actions before the setState. Since these don't
necessarily have a root this is tricky. #33190
- [x] Disable for `useDeferredValue`. ~Since it also goes through
`markRootUpdated` and schedules a Transition lane it'll get a default
indicator even though it probably shouldn't have one.~ EDIT: Turns out
this just works because it doesn't go through `markRootUpdated` when
work is left behind.
- [x] Implement built-in DOM version by default. #33162
When we're entangled with an async action lane we use that lane instead
of the currentEventTransitionLane. Conversely, if we start a new async
action lane we reuse the currentEventTransitionLane.
So they're basically supposed to be in sync but they're not if you
resolve the async action and then schedule new stuff in the same event.
Then you end up with two transitions in the same event with different
lanes.
By stashing it like this we fix that but it also gives us an opportunity
to check just the currentEventTransitionLane to see if this event
scheduled any regular Transition updates or Async Transitions.
This keeps track of the transition lane allocated for this event. I want
to be able to use the current one within sync work flushing to know
which lane needs its loading indicator cleared.
It's also a bit weird that transition work scheduled inside sync updates
in the same event aren't entangled with other transitions in that event
when `flushSync` is.
Therefore this moves it to reset after flushing.
It should have no impact. Just splitting it out into a separate PR for
an abundance of caution.
The only thing this might affect would be if the React internals throws
and it doesn't reset after. But really it doesn't really have to reset
and they're all entangled anyway.
When we get the source location for "View source for this element" we
should be using the enclosing function of the callsite of the child. So
that we don't just point to some random line within the component.
This is similar to the technique in #33136.
This technique is now really better than the fake throw technique, when
available. So I now favor the owner technique. The only problem it's
only available in DEV and only if it has a child that's owned (and not
filtered).
We could implement this same technique for the error that's thrown in
the fake throwing solution. However, we really shouldn't need that at
all because for client components we should be able to call
`inspect(fn)` at least in Chrome which is even better.
Enabled in experimental channel.
We know this is critical semantics to enforce at the HTML level since if
you don't then you can't add explicit boundaries after the fact.
However, this might have to go in a major release to allow for
upgrading.
## Summary
Our builds generate files with a `.mjs` file extension. These are
currently filtered out by `ReactFlightWebpackPlugin` so I am updating it
to support this file extension.
This fixes https://github.com/facebook/react/issues/33155
## How did you test this change?
I built the plugin with this change and used `yalc` to test it in my
project. I confirmed the expected files now show up in
`react-client-manifest.json`
React Compiler's program traversal logic is pretty lengthy and complex
as we've added a lot of features piecemeal. `compileProgram` is 300+
lines long and has confusing control flow (defining helpers inline,
invoking visitors, mutating-asts-while-iterating, mutating global
`ALREADY_COMPILED` state).
- Moved more stuff to `ProgramContext`
- Separated `compileProgram` into a bunch of helpers
Tested by syncing this stack to a Meta codebase and observing no
compilation output changes (D74487851, P1806855669, P1806855379)
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33147).
* #33149
* #33148
* __->__ #33147
Stacked on #33150.
We use `noop` functions in a lot of places as place holders. I don't
think there's any real optimizations we get from having separate
instances. This moves them to use a common instance in `shared/noop`.
New take on #29716
## Summary
Template literals consisting entirely of constant values will be inlined
to a string literal, effectively replacing the backticks with a double
quote.
This is done primarily to make the resulting instruction a string
literal, so it can be processed further in constant propatation. So this
is now correctly simplified to `true`:
```js
`` === "" // now true
`a${1}` === "a1" // now true
```
If a template string literal can only partially be comptime-evaluated,
it is not that useful for dead code elimination or further constant
folding steps and thus, is left as-is in that case. Same is true if the
literal contains an array, object, symbol or function.
## How did you test this change?
See added tests.
(Almost) all pragmas are now one of the following:
- `@...TestOnly`: custom pragma for test fixtures
- `@<configName>` | `@<configName>:true`: enables with either true or a
default enabled value
- `@<configName>:<json value>`
`fragmentInstance.dispatchEvent(evt)` calls `element.dispatchEvent(evt)`
on the fragment's host parent. This mimics bubbling if the
`fragmentInstance` could receive an event itself.
If the parent is disconnected, there is a dev warning and no event is
dispatched.
## Summary
`-constant` is represented as a `UnaryExpression` node that is currently
not part of constant folding. If the operand is a constant number, the
node is folded to `constant * -1`. This also coerces `-0` to `0`,
resulting in `0 === -0` being folded to `true`.
## How did you test this change?
See attached tests
Follow up to #33136.
This clarifies in the types where the conversion happens from a CallSite
which we use to simulate getting the enclosing line/col to a
FunctionLocation which doesn't represent a CallSite but actually just
the function which only has an enclosing line/col.
This enables `focus` and `focusLast` methods on FragmentInstances to
search nested host components, depth first. Attempts focus on each child
and bails if one is successful. Previously, only the first level of host
children would attempt focus.
Now if we have an example like
```
component MenuItem() {
return (<div><a>{...}</a></div>)
}
component Menu() {
return <Fragment>{items.map(i => <MenuItem i={i} />)}</Fragment>
}
```
We can target focus on the first or last a tag, rather than checking
each wrapping div and then noop.
Stacked on #33135.
This encodes the line/column of the enclosing function as part of the
stack traces. When that information is available.
I adjusted the fake function code generation so that the beginning of
the arrow function aligns with these as much as possible.
This ensures that when the browser tries to look up the line/column of
the enclosing function, such as for getting the function name, it gets
the right one. If we can't get the enclosing line/column, then we encode
it at the beginning of the file. This is likely to get a miss in the
source map identifiers, which means that the function name gets
extracted from the runtime name instead which is better.
Another thing where this is used is the in the Performance Track.
Ideally that would be fixed by
https://issues.chromium.org/u/1/issues/415968771 but the enclosing
information is useful for other things like the function name resolution
anyway.
We can also use this for the "View source for this element" in React
DevTools.
This is first step to include more enclosing line/column in the parsed
data.
We install our own `prepareStackTrace` to collect structured callsite
data and only fall back to parsing the string if it was already
evaluated or if `prepareStackTrace` doesn't work in this environment.
We still mirror the default V8 format for encoding the function name
part. A lot of this is covered by tests already.
## Summary
When using React DevTools to highlight component updates, the highlights
would sometimes appear behind elements that use the browser's
[top-layer](https://developer.mozilla.org/en-US/docs/Glossary/Top_layer)
(such as `<dialog>` elements or components using the Popover API). This
made it difficult to see which components were updating when they were
inside or behind top-layer elements.
This PR fixes the issue by using the Popover API to ensure that
highlighting appears on top of all content, including elements in the
top-layer. The implementation maintains backward compatibility with
browsers that don't support the Popover API.
## How did you test this change?
I tested this change in the following ways:
1. Manually tested in Chrome (which supports the Popover API) with:
- Created a test application with React components inside `<dialog>`
elements and custom elements using the Popover API
- Verified that component highlighting appears above these elements when
they update
- Confirmed that highlighting displays correctly for nested components
within top-layer elements
2. Verified backward compatibility:
- Tested in browsers without Popover API support to ensure fallback
behavior works correctly
- Confirmed that no errors occur and highlighting still functions as
before
3. Ran the React DevTools test suite:
- All tests pass successfully
- No regressions were introduced
[demo-page](https://devtools-toplayer-demo.vercel.app/)
[demo-repo](https://github.com/yongsk0066/devtools-toplayer-demo)
### AS-IS
https://github.com/user-attachments/assets/dc2e1281-969f-4f61-82c3-480153916969
### TO-BE
https://github.com/user-attachments/assets/dd52ce35-816c-42f0-819b-0d5d0a8a21e5
This adds `compareDocumentPosition(otherNode)` to fragment instances.
The semantics implemented are meant to match typical element
positioning, with some fragment specifics. See the unit tests for all
expectations.
- An element preceding a fragment is `Node.DOCUMENT_POSITION_PRECEDING`
- An element after a fragment is `Node.DOCUMENT_POSITION_FOLLOWING`
- An element containing the fragment is
`Node.DOCUMENT_POSITION_PRECEDING` and
`Node.DOCUMENT_POSITION_CONTAINING`
- An element within the fragment is
`Node.DOCUMENT_POSITION_CONTAINED_BY`
- An element compared against an empty fragment will result in
`Node.DOCUMENT_POSITION_DISCONNECTED` and
`Node.DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC`
Since we assume a fragment instances target children are DOM siblings
and we want to compare the full fragment as a pseudo container, we can
compare against the first target child outside of handling the special
cases (empty fragments and contained elements).
Multiple things here:
- Improve the mean calculation for metrics so we don't report 0 when
web-vitals fail to be retrieved
- improve ui chaos monkey to use puppeteer APIs since only those trigger
INP/CLS metrics since we need emulated mouse clicks
- Add logic to navigate to a temp page after render since some
web-vitals metrics are only calculated when the page is backgrounded
- Some readability improvements
Originally I thought it was important that SSR used the same View
Transition name as the client so that the Fizz runtime could emit those
names and then the client could pick up and take over. However, I no
longer believe that approach is feasible. Instead, the names can be
generated only during that particular animation.
Therefore we can simplify the auto name assignment to not have to
consider the hydration.
Stacked on #33129. Flagged behind `enableHydrationChangeEvent`.
If you type into a controlled input before hydration and something else
rerenders like a setState in an effect, then the controlled input will
reset to whatever React thought it was. Even with event replaying that
this is stacked on, if the second render happens before event replaying
has fired in a separate task.
We don't want to flush inside the commit phase because then things like
flushSync in these events wouldn't work since they're inside the commit
stack.
This flushes all event replaying between renders by flushing it at the
end of `flushSpawned` work. We've already committed at that point and is
about to either do subsequent renders or yield to event loop for passive
effects which could have these events fired anyway. This just ensures
that they've already happened by the time subsequent renders fire. This
means that there's now a type of event that fire between sync render
passes.
This fixes a long standing issue that controlled inputs gets out of sync
with the browser state if it's changed before we hydrate.
This resolves the issue by replaying the change events (click, input and
change) if the value has changed by the time we commit the hydration.
That way you can reflect the new value in state to bring it in sync. It
does this whether controlled or uncontrolled.
The idea is that this should be ok to replay because it's similar to the
continuous events in that it doesn't replay a sequence but only reflects
the current state of the tree.
Since this is a breaking change I added it behind
`enableHydrationChangeEvent` flag.
There is still an additional issue remaining that I intend to address in
a follow up. If a `useLayoutEffect` triggers an sync rerender on
hydration (always a bad idea) then that can rerender before we have had
a chance to replay the change events. If that renders through a input
then that input will always override the browser value with the
controlled value. Which will reset it before we've had a change to
update to the new value.
Note that bailing out adds false positives for hoisted functions whose
only references are within other functions. For example, this rewrite
would be safe.
```js
// source program
function foo() {
return bar();
}
function bar() {
return 42;
}
// compiler output
let bar;
if (/* deps changed */) {
function foo() {
return bar();
}
bar = function bar() {
return 42;
}
}
```
These false positives are difficult to detect because any maybe-call of
foo before the definition of bar would be invalid.
Instead of bailing out, we should rewrite hoisted function declarations
to the following form.
```js
let bar$0;
if (/* deps changed */) {
// All references within the declaring memo block
// or before the function declaration should use
// the original identifier `bar`
function foo() {
return bar();
}
function bar() {
return 42;
}
bar$0 = bar;
}
// All references after the declaring memo block
// or after the function declaration should use
// the rewritten declaration `bar$0`
```
I noticed that we increase this in the recursive part of the algorithm.
This would mean that we'd count a key more than once if it has Server
Components inside it recursively resolving. This moves it out to where
we enter from toJSON. Which is called once per JSON entry (and therefore
once per key).
This revisits a validation I built a while ago, trying to make it more strict this time to ensure that it's high-signal.
We detect function expressions which are *known* mutable — they definitely can modify a variable defined outside of the function expression itself (modulo control flow). This uses types to look for known Store and Mutate effects only, and disregards mutations of effects. Any such function passed to a location with a Freeze effect is reported as a validation error.
This is behind a flag and disabled by default. If folks agree this makes sense to revisit, i'll test out internally and we can consider enabling by default.
ghstack-source-id: 075a731444ce95e52dbd5ea3be85c16d428927f5
Pull Request resolved: https://github.com/facebook/react/pull/33079
If a function captures a mutable value but never gets called, we don't infer a mutable range for that function. This means that we also don't alias the function with its mutable captures.
This case is tricky, because we don't generally know for sure what is a mutation and what may just be a normal function call. For example:
```js
hook useFoo() {
const x = makeObject();
return () => {
return readObject(x); // could be a mutation!
}
}
```
If we pessimistically assume that all such cases are mutations, we'd have to group lots of memo scopes together unnecessarily. However, if there is definitely a mutation:
```js
hook useFoo(createEntryForKey) {
const cache = new WeakMap();
return (key) => {
let entry = cache.get(key);
if (entry == null) {
entry = createEntryForKey(key);
cache.set(key, entry); // known mutation!
}
return entry;
}
}
```
Then we have to ensure that the function and its mutable captures alias together and end up in the same scope. However, aliasing together isn't enough if the function and operands all have empty mutable ranges (end = start + 1).
This pass finds function expressions and object methods that have an empty mutable range and known-mutable operands which also don't have a mutable range, and ensures that the function and those operands are aliased together *and* that their ranges are updated to end after the function expression. This is sufficient to ensure that a reactive scope is created for the alias set.
NOTE: The alternative is to reject these cases. If we do that we'd also want to similarly disallow cases like passing a mutable function to a hook.
ghstack-source-id: 5d8158246a320e80d8da3f0e395ac1953d8920a2
Pull Request resolved: https://github.com/facebook/react/pull/33078
Building on mofeiz's recent work to type constructors. Also, types for reanimated values which are useful in the next PR.
ghstack-source-id: 1c81e213a11337ac7e9c85a429ecf3f1d1adef66
Pull Request resolved: https://github.com/facebook/react/pull/33077
This pass didn't previously report the precise difference btw inferred/manual dependencies unless a debug flag was set. But the error message is really good (nice job mofeiz): the only catch is that in theory the inferred dep could be a temporary that can't trivially be reported to the user.
But the messages are really useful for quickly verifying why the compiler couldn't preserve memoization. So here we switch to outputting a detailed message about the discrepancy btw inferred/manual deps so long as the inferred dep root is a named variable. I also slightly adjusted the message to handle the case where there is no diagnostic, which can occur if there were no manual deps but the compiler inferred a dependency.
ghstack-source-id: 534f6f1fec0855e05e85077eba050eb2ba254ef8
Pull Request resolved: https://github.com/facebook/react/pull/33095
If a JSX attribute value is a string that contains unicode or other characters that need special escaping, we wrap the attribute value in an expression container. However, our unicode to detect this only handled the basic unicode character plane, not the "astral" plane which includes emojis.
This PR updates the regex to detect such extended characters and also use an expression container.
ghstack-source-id: 6d9c8e4dd22285077108e2fa53d66154d1b781fb
Pull Request resolved: https://github.com/facebook/react/pull/33096
Our runtime results are still bogus, but so far this tweak let's the llm
use the tools a little more intelligently.
example:
---
```js
import React from 'react';
function App() {
const [count, setCount] = React.useState(0);
const [data, setData] = React.useState([]);
React.useEffect(() => {
const processData = () => {
console.log("Processing data...");
const newData = [];
for (let i = 0; i < 1000000000; i++) {
newData.push({ id: i, value: Math.random() * count });
}
return newData;
};
const processedData = processData();
setData(processedData);
}, [count]);
return (
<div>
<p>Count: {count}</p>
<p>Data Length: {data.length}</p>
<ul>
{data.slice(0, 5).map((item) => (
<li key={item.id}>Item {item.id}: {item.value.toFixed(2)}</li>
))}
</ul>
</div>
);
};
```
why is this component slow? use the react tools to figure this out.
> I'll analyze why this component is slow using the React tools. Let's
first evaluate the performance of the original code.
>
[review-react-runtime ...]
>
> The performance measurement tool timed out, which is a strong
indication of just how severe the performance issue is in this
component. Let's now try to compile the code to see if React Compiler
can identify any issues:
>
[compile...]
>
> Now I understand the issue. Let's analyze why this component > is
extremely slow:
> Main Performance Issues:
>
> Massive Data Processing: The component is trying to create an array
with a billion (1,000,000,000) objects in the processData function. This
is an enormous amount of data that will:
>
> Consume massive amounts of memory
> Take an extremely long time to process
> Likely crash the browser
>
>
> Unnecessary Recalculation: The effect depends on [count], meaning
every time the count changes, it will reprocess this enormous dataset.
> Inefficient Data Handling: Even though only 5 items are displayed, the
component processes a billion items.
>
> Let's fix these issues:
>
[compile...]
>
> Now let's check if our modified code performs better:
>
[review-react-runtime...]
>
> Excellent! The performance has dramatically improved. Now let's check
the React documentation to make sure we're following the best practices:
>
[query-react-dev-docs...]
(hit the maximum length conversation limit because i'm on a free plan)
Since we use esbuild we need to correctly move dependencies that are
required at runtime into `dependencies` and other packages that are only
used in development in to `devDependencies`. This ensures the correct
packages are included in the build.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33101).
* #33085
* #33084
* #33083
* #33082
* __->__ #33101
Because we now decided whether to outline in the flushing phase, when
we're writing the preamble we don't yet know if we will make that
decision so we don't know if it's safe to omit the external runtime.
However, if you are providing an external runtime it's probably a pretty
safe bet you're streaming something dynamically that's likely to need it
so we can always include it.
The main thing is that this makes it hard to test it because it affects
our tests in ways it wouldn't otherwise so we have to add a bunch of
conditions.
Stacked on #33076.
This fixes a bug where we used the "complete" status but the
DOMContentLoaded event. This checks for not "loading" instead.
We also add a new status where the boundary has been marked as complete
by the server but has not yet flushed either due to being throttled,
suspended on CSS or animating.
Stacked on #33073.
React semantics is that Suspense boundaries reveal with a throttle
(300ms). That helps avoid flashing reveals when a stream reveals many
individual steps back to back. It can also improve overall performance
by batching the layout and paint work that has to happen at each step.
Unfortunately we never implemented this for SSR streaming - only for
client navigations. This is highly noticeable on very dynamic sites with
lots of Suspense boundaries. It can look good with a client nav but feel
glitchy when you reload the page or initial load.
This fixes the Fizz runtime to be throttled and reveals batched into a
single paint at a time. We do this by first tracking the last paint
after the complete (this will be the first paint if `rel="expect"` is
respected). Then in the `completeBoundary` operation we queue the
operation and then flush it all into a throttled batch.
Another motivation is that View Transitions need to operate as a batch
and individual steps get queued in a sequence so it's extra important to
include as much content as possible in each animated step. This will be
done in a follow up for SSR View Transitions.
Stacked on #33066 and #33068.
Currently we're passing `errorDigest` to `completeBoundary` if there is
a client side error (only CSS loading atm). This only exists because of
`completeBoundaryWithStyles`. Normally if there's a server-side error
we'd emit the `clientRenderBoundary` instruction instead. This adds
unnecessary code to the common case where all styles are in the head.
This is about to get worse with batching because client render shouldn't
be throttled but complete should be.
The first commit moves the client render logic inline into
`completeBoundaryWithStyles` so we only pay for it when styles are used.
However, the approach I went with in the second commit is to reuse the
`$RX` instruction instead (`clientRenderBoundary`). That way if you have
both it ends up being amortized. However, it does mean we have to emit
the `$RX` (along with the `$RC` helper if any
`completeBoundaryWithStyles` instruction is needed.
Stacked on #33065.
The runtime is about to be a lot more complicated so we need to start
sharing some more code.
The problem with sharing code is that we want the inline runtime to as
much as possible be isolated in its scope using only a few global
variables to refer across runtimes.
A problem with Closure Compiler is that it refuses to inline functions
if they have closures inside of them. Which makes sense because of how
VMs work it can cause memory leaks. However, in our cases this doesn't
matter and code size matters more. So we can't use many clever tricks.
So this just favors writing the source in the inline form. Then we add
an extra compiler pass to turn those global variables into local
variables in the external runtime.
We weren't treating terminal operands as eligible for memoization in PruneNonEscapingScopes, which meant that they could end up un-memoized. Terminal operands can also be compound ReactiveValues like SequenceExpressions, so part of the fix is to make sure we don't just recurse into compound values but record the full aliasing information we would for top-level instructions.
Still WIP, this needs to handle terminals other than for..of.
ghstack-source-id: 09a29230514e3bc95d1833cd4392de238fabbeda
Pull Request resolved: https://github.com/facebook/react/pull/33062
## Summary
Fix babel presets, and add a bit more context to the tool so that it is
more reliable
## How did you test this change?
Manually tested the mcp integrated with claude desktop
We normally expect the segment to exist whatever the client does while
streaming. However, when hydration errors at the root of the shell for a
whole document render, then we clear nodes from body which can include
our segments. We don't need them anymore because we switched to client
rendering.
It triggers an error accessing parent node which can safely be ignored.
This just helps avoid confusion in this scenario.
This also covers up the error in #33067. Which doesn't actually cause
any visible problems other than error logging. However, ideally we
wouldn't emit completeBoundary instructions if the boundary is inside a
cancelled fallback.
```js
function Component() {
useEffect(() => {
let hasCleanedUp = false;
document.addEventListener(..., () => hasCleanedUp ? foo() : bar());
// effect return values shouldn't be typed as frozen
return () => {
hasCleanedUp = true;
}
};
}
```
### Problem
`PruneHoistedContexts` currently strips hoisted declarations and
rewrites the first `StoreContext` reassignment to a declaration. For
example, in the following example, instruction 0 is removed while a
synthetic `DeclareContext let` is inserted before instruction 1.
```js
// source
const cb = () => x; // reference that causes x to be hoisted
let x = 4;
x = 5;
// React Compiler IR
[0] DeclareContext HoistedLet 'x'
...
[1] StoreContext reassign 'x' = 4
[2] StoreContext reassign 'x' = 5
```
Currently, we don't account for `DeclareContext let`. As a result, we're
rewriting to insert duplicate declarations.
```js
// source
const cb = () => x; // reference that causes x to be hoisted
let x;
x = 5;
// React Compiler IR
[0] DeclareContext HoistedLet 'x'
...
[1] DeclareContext Let 'x'
[2] StoreContext reassign 'x' = 5
```
### Solution
Instead of always lowering context variables to a DeclareContext
followed by a StoreContext reassign, we can keep `kind: 'Const' | 'Let'
| 'Reassign' | etc` on StoreContext.
Pros:
- retain more information in HIR, so we can codegen easily `const` and
`let` context variable declarations back
- pruning hoisted `DeclareContext` instructions is simple.
Cons:
- passes are more verbose as we need to check for both `DeclareContext`
and `StoreContext` declarations
~(note: also see alternative implementation in
https://github.com/facebook/react/pull/32745)~
### Testing
Context variables are tricky. I synced and diffed changes in a large
meta codebase and feel pretty confident about landing this. About 0.01%
of compiled files changed. Among these changes, ~25% were [direct
bugfixes](https://www.internalfb.com/phabricator/paste/view/P1800029094).
The [other
changes](https://www.internalfb.com/phabricator/paste/view/P1800028575)
were primarily due to changed (corrected) mutable ranges from
https://github.com/facebook/react/pull/33047. I tried to represent most
interesting changes in new test fixtures
`
Fixes an edge case in React Compiler's effects inference model.
Returned values should only be typed as 'frozen' if they are (1) local
and (2) not a function expression which may capture and mutate this
function's outer context. See test fixtures for details
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33047).
* #32765
* #32747
* __->__ #33047
## Summary
Add a way for the agent to get some data on the performance of react
code
## How did you test this change?
Tested function independently and directly with claude desktop app
---------
Co-authored-by: Sebastian "Sebbie" Silbermann <sebastian.silbermann@vercel.com>
Same principle as #33029 but for Flight.
We pretty aggressively create separate rows for things in Flight (every
Server Component that's an async function create a microtask). However,
sync Server Components and just plain Host Components are not. Plus we
should ideally ideally inline more of the async ones in the same way
Fizz does.
This means that we can create rows that end up very large. Especially if
all the data is already available. We can't show the parent content
until the whole thing loads on the client.
We don't really know where Suspense boundaries are for Flight but any
Element is potentially a point that can be split.
This heuristic counts roughly how much we've serialized to block the
current chunk and once a limit is exceeded, we start deferring all
Elements. That way they get outlined into future chunks that are later
in the stream. Since they get replaced by Lazy references the parent can
potentially get unblocked.
This can help if you're trying to stream a very large document with a
client nav for example.
Adds Fragment Ref support to RN through the Fabric config, starting with
`observeUsing`/`unobserveUsing`. This is mostly a copy from the
implementation on DOM, and some of it can likely be shared in the future
but keeping it separate for now and we can refactor as we add more
features.
Added a basic test with Fabric, but testing specific methods requires so
much mocking that it doesn't seem valuable here.
I built Fabric and ran on the Catalyst app internally to test with
intersection observers end to end.
Stacked on #32736.
That way you can find the owner stack of each component that rerendered
for context.
In addition to the JSX callsite tasks that we already track, I also
added tracking of the first `setState` call before rendering.
We then run the "Update" entries in that task. That way you can find the
callsite of the first setState and therefore the "cause" of a render
starting by selecting the "Update" track.
Unfortunately this is blocked on bugs in Chrome that makes it so that
these stacks are not reliable in the Performance tab. It basically just
doesn't work.
This is a new extension that Chrome added to the existing
`console.timeStamp` similar to the extensions added to
`performance.measure`. This one should be significantly faster because
it doesn't have the extra object indirection, it doesn't return a
`PerformanceMeasure` entry and doesn't register itself with the global
system of entries.
I also use `performance.measure` in DEV for errors since we can attach
the error to the `properties` extension which doesn't exist for
`console.timeStamp`.
A downside of using this API is that there's no programmatic API for the
site itself to collect its own logs from React. Which the previous
allowed us to use the standard `performance.getEntries()` for. The
recommendation instead will be for the site to patch `console.timeStamp`
if it wants to collect measurements from React just like you're
recommended to patch `console.error` or `fetch` or whatever to collect
other instrumentation metrics.
This extension works in Chrome canary but it doesn't yet work fully in
Chrome stable. We might want to wait until it has propagated to Chrome
to stable. It should be in Chrome 136.
Follow up to #33027.
This enhances the heuristic so that we accumulate the size of the
currently written boundaries. Starting from the size of the root (minus
preamble) for the shell.
This ensures that if you have many small boundaries they don't all
continue to get inlined. For example, you can wrap each paragraph in a
document in a Suspense boundary to regain document streaming
capabilities if that's what you want.
However, one consideration is if it's worth producing a fallback at all.
Maybe if it's like `null` it's free but if it's like a whole alternative
page, then it's not. It's possible to have completely useless Suspense
boundaries such as when you nest several directly inside each other. So
this uses a limit of at least 500 bytes of the content itself for it to
be worth outlining at all. It also can't be too small because then for
example a long list of paragraphs can never be outlined.
In the fixture I straddle this limit so some paragraphs are too small to
be considered. An unfortunate effect of that is that you can end up with
some of them not being outlined which means that they appear out of
order. SuspenseList is supposed to address that but it's unfortunate.
The limit is still fairly high though so it's unlikely that by default
you'd start outlining anything within the viewport at all. I had to
reduce the `progressiveChunkSize` by an order of magnitude in my fixture
to try it out properly.
`requestFormReset` incorrectly tries to get the current dispatch queue
from the Fiber. However, the Fiber might be the workInProgress which is
an inconsistent state.
This hack just tries the other Fiber if it detects one of the known
inconsistent states but there can be more.
Really we should stash the dispatch queue somewhere stateful which is
effectively what `setState` does by binding it to the closure.
## Summary
We don't need the isArray check for this experiment, as
`fastAddProperties` already does the same. Also renaming
slowAddProperties to make it clearer we can fully remove this codepath
once fastAddProperties is fully rolled out.
## How did you test this change?
```
yarn test packages/react-native-renderer -r=xplat --variant=true
```
2025-04-29 11:10:18 +01:00
727 changed files with 31671 additions and 9287 deletions
* Fix for string attribute values with emoji [#33096](https://github.com/facebook/react/pull/33096) by [@josephsavona](https://github.com/josephsavona)
'Hooks must be called at the top level in the body of a function component or custom hook, and may not be called within function expressions. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)',
loc: callee.loc,
description:`Cannot call ${hookKind} within a function component`,
description:`Cannot call ${hookKind==='Custom'?'hook':hookKind} within a function expression`,
'React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected',
description:DEBUG
?`The inferred dependency was \`${prettyPrintScopeDependency(
dep,
)}\`, but the source dependencies were [${validDepsInMemoBlock
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ InvalidReact: React Compiler has skipped optimizing this component because one or more React ESLint rules were disabled. React Compiler only works when your components follow all the rules of React, disabling them may result in unexpected or incorrect behavior. eslint-disable my-app/react-rule (3:3)
| ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected (4:11)
| ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `props.items`, but the source dependencies were [props?.items, props.cond]. Inferred different dependency than source (4:11)
| ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected (4:11)
| ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `props.items`, but the source dependencies were [props?.items, props.cond]. Inferred different dependency than source (4:11)
| ^^^^ InvalidReact: This argument is a function which modifies local variables when called, which can bypass memoization and cause the UI not to update. Functions that are returned from hooks, passed as arguments to hooks, or passed as props to components may not mutate local variables (5:7)
InvalidReact: The function modifies a local variable here (6:6)
| ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected (3:7)
| ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `props.items.edges.nodes`, but the source dependencies were [props.items?.edges?.nodes]. Inferred different dependency than source (3:7)
| ^^ InvalidReact: This argument is a function which modifies local variables when called, which can bypass memoization and cause the UI not to update. Functions that are returned from hooks, passed as arguments to hooks, or passed as props to components may not mutate local variables (7:7)
InvalidReact: The function modifies a local variable here (5:5)
| ^^^^^^^^^^^^^^^^^ InvalidReact: Ref values (the `current` property) may not be accessed during render. (https://react.dev/reference/react/useRef) (3:3)
| ^^^^ InvalidReact: This argument is a function which modifies local variables when called, which can bypass memoization and cause the UI not to update. Functions that are returned from hooks, passed as arguments to hooks, or passed as props to components may not mutate local variables (7:9)
InvalidReact: The function modifies a local variable here (8:8)
| ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected (11:13)
| ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `Ref.current`, but the source dependencies were []. Inferred dependency not present in source (11:13)
| ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected (11:13)
| ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected. The inferred dependency was `notaref.current`, but the source dependencies were []. Inferred dependency not present in source (11:13)
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