## Overview
The clever trick in https://github.com/facebook/react/pull/29799 turns
out to not work because signedsource includes the generated hash in the
header. Reverts back to checking git diff, filtering out the REVISION
file and `@generated` headers.
There are two cases where it's legit/intended to remove scopes, and we can inline the scope rather than reify a "pruned" scope:
* Scopes that contain a single instruction with a hook call. The fact that we create a scope in this case at all is just an artifact of it being simpler to do this and remove the scope later rather than try to avoid creating it in the first place. So for these scopes, we can just inline them.
* Scopes that are provably non-escaping. Removing the scope is an optimization, not a case of us having to prune away something that should be there. So again, its fine to inline in this case.
I found this from syncing the stack internally and looking at differences in compiled output. The latter case was most common but the first case is just an obvious improvement.
ghstack-source-id: 80610ddafa
Pull Request resolved: https://github.com/facebook/react/pull/29820
Adds additional information to the CompileSuccess LoggerEvent:
* `prunedMemoBlocks` is the number of reactive scopes that were pruned for some reason.
* `prunedMemoValues` is the number of unique _values_ produced by those scopes.
Both numbers exclude blocks that are just a hook call - ie although we create and prune a scope for eg `useState()`, that's just an artifact of the sequencing of our pipeline. So what this metric is counting is cases of _other_ values that go unmemoized. See the new fixture, which takes advantage of improvements in the snap runner to optionally emit the logger events in the .expect.md file if you include the "logger" pragma in a fixture.
ghstack-source-id: c2015bb556
Pull Request resolved: https://github.com/facebook/react/pull/29810
Mostly addresses the issue with non-reactive pruned scopes. Before, values from pruned scopes would not be memoized, but could still be depended upon by downstream scopes. However, those downstream scopes would assume the value could never change. This could allow the developer to observe two different versions of a value - the freshly created one (if observed outside a scope) or a cached one (if observed inside, or through) a scope which used the value but didn't depend on it.
The fix here is to consider the outputs of pruned reactive scopes as reactive. Note that this is a partial fix because of things like control variables — the full solution would be to mark these values as reactive, and then re-run InferReactivePlaces. We can do this once we've fully converted our pipeline to use HIR everywhere. For now, this should fix most issues in practice because PruneNonReactiveDependencies already does basic alias tracking (see new fixture).
ghstack-source-id: 364430bbec
Pull Request resolved: https://github.com/facebook/react/pull/29790
There's a category of bug currently where pruned reactive scopes whose outputs are non-reactive can have their code end up inlining into another scope, moving the location of the instruction. Any value that had a scope assigned has to have its order of evaluation preserved, despite the fact that it got pruned, so naively we could just force every pruned scope to have its declarations promoted to named variables.
However, that ends up assigning names to _tons_ of scope declarations that don't really need to be promoted. For example, a scope with just a hook call ends up with:
```
const x = useFoo();
=>
scope {
$t0 = Call read useFoo$ (...);
}
$t1 = StoreLocal 'x' = read $t0;
```
Where t0 doesn't need to be promoted since it's used immediately to assign to another value which is a non-temporary.
So the idea of this PR is that we can track outputs of pruned scopes which are directly referenced from inside a later scope. This fixes one of the two cases of the above pattern. We'll also likely have to consider values from pruned scopes as always reactive, i'll do that in the next PR.
ghstack-source-id: b37fb9a7cb
Pull Request resolved: https://github.com/facebook/react/pull/29789
There are a few places where we want to check whether a value actually got memoized, and we currently have to infer this based on values that "should" have a scope and whether a corresponding scope actually exists. This PR adds a new ReactiveStatement variant to model a reactive scope block that was pruned for some reason, and updates all the passes that prune scopes to instead produce this new variant.
ghstack-source-id: aea6dab469
Pull Request resolved: https://github.com/facebook/react/pull/29781
## Overview
Reverts https://github.com/facebook/react/pull/26616 and implements the
suggested way instead.
This change in #26616 broken the internal sync command, which now
results in duplicated `@generated` headers. It also makes it harder to
detect changes during the diff train sync. Instead, we will check for
changes, and if there are changes sign the files and commit them to the
sync branch.
## Strategy
The new sync strategy accounts for the generated headers during the
sync:
- **Revert Version**: Revert the version strings
- **Revert @generated**: Re-sign the files (will be the same hash as
before if unchanged)
- **Check**: Check if there are changes **if not, skip**
- **Re-apply Version**: Now add back the new version string
- **Re-sign @generated**: And re-generate the headers
Then commit to branch. This ensures that if there are no changes, we'll
skip.
---------
Co-authored-by: Timothy Yung <yungsters@gmail.com>
## Summary
See #29737
## How did you test this change?
As the feature requires module support and the test runner does
currently not support running tests as modules, I could only test it via
playground.
The goal is to improve speed of the development by inlining and DCE
unused branches.
We have the ability to preserve some variable names and pretty print in
the production version so might as well do the same with DEV.
When we made stylesheets suspend even during high priority updates we
exposed a bug in the loading tracking of stylesheets that are loaded as
part of the preamble. This allowed these stylesheets to put suspense
boundaries into fallback mode more often than expected because cases
where a stylesheet was server rendered could now cause a fallback to
trigger which was never intended to happen.
This fix updates resource construction to evaluate whether the instance
exists in the DOM prior to construction and if so marks the resource as
loaded and inserted.
One ambiguity that needed to be solved still is how to tell whether a
stylesheet rendered as part of a late Suspense boundary reveal is
already loaded. I updated the instruction to clear out the loading
promise after successfully loading. This is useful because later if we
encounter this same resource again we can avoid the microtask if it is
already loaded. It also means that we can concretely understand that if
a stylesheet is in the DOM without this marker then it must have loaded
(or errored) already.
This PR makes it so we always emit a const VariableDeclaration for
compiled functions in gating mode. If the original declaration's parent
was an ExportDefaultDeclaration we'll also append a new
ExportDefaultDeclaration pointing to the new identifier. This allows
code that adds optional properties to the function declaration to still
work in gating mode
ghstack-source-id: 5705479135
Pull Request resolved: https://github.com/facebook/react/pull/29806
When gating is enabled, any function declaration properties that were
previously set (typically `Function.displayName`) would cause a crash
after compilation as the original identifier is no longer present.
ghstack-source-id: beb7e25856
Pull Request resolved: https://github.com/facebook/react/pull/29802
This refactors key warning to happen inline after we've matched a Fiber.
I didn't want to do that originally because it was riskier. But it turns
out to be straightforward enough.
This lets us use that Fiber as the source of the warning which matters
to DevTools because then DevTools can associate it with the right
component after it mounts.
We can also associate the duplicate key warning with this Fiber. That
way we'll get the callsite with the duplicate key on the stack and can
associate this warning with the child that had the duplicate.
I kept the forked DevTools tests because the warning now is counted on
the Child instead of the Parent (18 behavior).
However, this won't be released in 19.0.0 so I only test this in
whatever the next version is.
Doesn't seem worth it to have a test for just the 19.0.0 behavior.
Fixes false positives where we currently disallow mutations of refs from callbacks passed to JSX, if the ref is also passed to jsx. We consider these to be mutations of "frozen" values, but refs are explicitly allowed to have interior mutability. The fix is to always allow (at leat within InferReferenceEffects) for refs to be mutated. This means we completely rely on ValidateNoRefAccessInRender to validate ref access and stop reporting false positives.
ghstack-source-id: 1a30609f5f
Pull Request resolved: https://github.com/facebook/react/pull/29733
Stacked on #29491
Previously if you aborted during a render the currently rendering task
would itself be aborted which will cause the entire model to be replaced
by the aborted error rather than just the slot currently being rendered.
This change updates the abort logic to mark currently rendering tasks as
aborted but allowing the current render to emit a partially serialized
model with an error reference in place of the current model.
The intent is to support aborting from rendering synchronously, in
microtasks (after an await or in a .then) and in lazy initializers. We
don't specifically support aborting from things like proxies that might
be triggered during serialization of props
## Summary
The test started to fail after
https://github.com/facebook/react/pull/29088.
Fork the test and the expected store state for:
- React 18.x, to represent the previous behavior
- React >= 19, to represent the current RDT behavior, where error can't
be connected to the fiber, because it was not yet mounted and shared
with DevTools.
Ideally, DevTools should start keeping track of such fibers, but also
distinguish them from some that haven't mounted due to Suspense or error
boundaries.
Stacked on #29551
Flight pings much more often than Fizz because async function components
will always take at least a microtask to resolve . Rather than
scheduling this work as a new macrotask Flight now schedules pings in a
microtask. This allows more microtasks to ping before actually doing a
work flush but doesn't force the vm to spin up a new task which is quite
common give n the nature of Server Components
While most builds of Flight and Fizz schedule work in new tasks some do
execute work synchronously. While this is necessary for legacy APIs like
renderToString for modern APIs there really isn't a great reason to do
this synchronously.
We could schedule works as microtasks but we actually want to yield so
the runtime can run events and other things that will unblock additional
work before starting the next work loop.
This change updates all non-legacy uses to be async using the best
availalble macrotask scheduler.
Browser now uses postMessage
Bun uses setTimeout because while it also supports setImmediate the
scheduling is not as eager as the same API in node
the FB build also uses setTimeout
This change required a number of changes to tests which were utilizing
the sync nature of work in the Browser builds to avoid having to manage
timers and tasks. I added a patch to install MessageChannel which is
required by the browser builds and made this patched version integrate
with the Scheduler mock. This way we can effectively use `act` to flush
flight and fizz work similar to how we do this on the client.
Summary
The dispatch function from useReducer is stable, so it is also non-reactive.
the related PR: #29665
the related comment: #29674 (comment)
I am not sure if the location of the new test file is appropriate😅.
How did you test this change?
Added the specific test compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/useReducer-returned-dispatcher-is-non-reactive.expect.md.
## Summary
There was an attempt to upgrade `ip` to 2.0.1 to mitigate CVE in
https://github.com/facebook/react/pull/29725#issuecomment-2150389616,
but there actually another one CVE in version `2.0.1`. Instead, migrate
to `internal-ip`, which similarly small package that we can use
Note: not upgrading to version 7+, because they are pure ESM.
## How did you test this change?
Validated that standalone version of RDT works and connects to the app.
## Summary
We currently do deep diffing for object props, and also use custom
differs, if they are defined, for props with custom attribute config.
The idea is to simply do a `===` comparison instead of all that work. We
will do less computation on the JS side, but send more data to native.
The hypothesis is that this change should be neutral in terms of
performance. If that's the case, we'll be able to get rid of custom
differs, and be one step closer to deleting view configs.
This PR adds the `enableShallowPropDiffing` feature flag to support this
experiment.
## How did you test this change?
With `enableShallowPropDiffing` hardcoded to `true`:
```
yarn test packages/react-native-renderer
```
This fails on the following test cases:
- should use the diff attribute
- should do deep diffs of Objects by default
- should skip deeply-nested changed functions
Which makes sense with this change. These test cases should be deleted
if the experiment is shipped.
This lets us ensure that we use the original V8 format and it lets us
skip source mapping. Source mapping every call can be expensive since we
do it eagerly for server components even if an error doesn't happen.
In the case of an error being thrown we don't actually always do this in
practice because if a try/catch before us touches it or if something in
onError touches it (which the default console.error does), it has
already been initialized. So we have to be resilient to thrown errors
having other formats.
These are not as perf sensitive since something actually threw but if
you want better perf in these cases, you can simply do something like
`onError(error) { console.error(error.message) }` instead.
The server has to be aware whether it's looking up original or compiled
output. I currently use the file:// check to determine if it's referring
to a source mapped file or compiled file in the fixture. A bundled app
can more easily check if it's a bundle or not.
Normally we take the renderClientElement path but this is an internal
fast path.
No tests because we don't run tests with console.createTask (which is
not easy since we test component stacks).
Ideally this would be covered by types but since the types don't
consider flags and DEV it doesn't really help.
## Overview
We didn't have any tests that ran in persistent mode with the xplat
feature flags (for either variant).
As a result, invalid test gating like in
https://github.com/facebook/react/pull/29664 were not caught.
This PR adds test flavors for `ReactFeatureFlag-native-fb.js` in both
variants.
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## Summary
Remove `startTransition` and `useActionState` from `react-server`
condition of react, as they should only stay in client bundle.
This will reduce the server bundle of react itself.
Found this while tracing where the `process.emit` was called.
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does the pull request solve?
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Following the instructions in the compiler/docs/DEVELOPMENT_GUIDE.md, we are stuck on the command `yarn snap --watch` because it calls readTestFilter even though the filter option is not enabled.
Use some clever git diffing to ignore lines that only change the
`@generated` header. We can't do this for the version string because the
version string can be embedded in lines with other changes, but this
header is always on one line.
This information is available in the regular stack but since that's
hidden behind an expando and our appended stack to logs is not hidden,
it hides the most important frames like the name of the current
component.
This is closer to what happens to the native stack.
We only include stacks if they're within a ReactFiberCallUserSpace call
frame. This should be most that have a current fiber but this is
critical to filtering out most React frames if the regular node_modules
filter doesn't work.
Most React warnings fire during the rendering phase and not inside a
user space function but some do like hooks warnings and setState in
render. This feature is more important if we port this to React DevTools
appending stacks to all logs where it's likely to originate from inside
a component and you want the line within that component to immediately
part of the visible stack.
One thing that kind sucks is that we don't have a reliable way to
exclude React internal stack frames. We filter node_modules but it might
not match. For other cases I try hard to only track the stack frame at
the root of React (e.g. immediately inside createElement) until the
ReactFiberCallUserSpace so we don't need the filtering to work. In this
case it's hard to achieve the same thing though. This is easier in RDT
because we have the start/end line and parsing of stack traces so we can
use that to exclude internals but that's a lot of code/complexity for
shipping within the library.
For example in Safari:
<img width="590" alt="Screenshot 2024-05-31 at 6 15 27 PM"
src="https://github.com/facebook/react/assets/63648/2820c8c0-8a03-42e9-8678-8348f66b051a">
Ideally warnOnUseFormStateInDev and useFormState wouldn't be included
since they're React internals. Before this change, the Counter.js line
also wasn't included though which points to exactly where the error is
within the user code.
(Note Server Components have V8 formatted lines and Client Components
have JSC formatted lines.)
RC releases are a special kind of prerelease build because unlike
canaries we shouldn't publish new RCs from any commit on `main`, only
when we intentionally bump the RC number. But they are still prerelases
— like canary and experimental releases, they should use exact version
numbers in their dependencies (no ^).
We only need to generate these builds during the RC phase, i.e. when the
canary channel label is set to "rc".
Example of resulting package.json output:
```json
{
"name": "react-dom",
"version": "19.0.0-rc.0",
"dependencies": {
"scheduler": "0.25.0-rc.0"
},
"peerDependencies": {
"react": "19.0.0-rc.0"
}
}
```
https://react-builds.vercel.app/prs/29736/files/oss-stable-rc/react-dom/package.json
Based on
- #29694
---
If an action in the useActionState queue errors, we shouldn't run any
subsequent actions. The contract of useActionState is that the actions
run in sequence, and that one action can assume that all previous
actions have completed successfully.
For example, in a shopping cart UI, you might dispatch an "Add to cart"
action followed by a "Checkout" action. If the "Add to cart" action
errors, the "Checkout" action should not run.
An implication of this change is that once useActionState falls into an
error state, the only way to recover is to reset the component tree,
i.e. by unmounting and remounting. The way to customize the error
handling behavior is to wrap the action body in a try/catch.
Mini-refactor of useActionState to only wrap the action in a transition
context if the dispatch is called during a transition. Conceptually, the
action starts as soon as the dispatch is called, even if the action is
queued until earlier ones finish.
We will also warn if an async action is dispatched outside of a
transition, since that is almost certainly a mistake. Ideally we would
automatically upgrade these to a transition, but we don't have a great
way to tell if the action is async until after it's already run.
Host Components can exist as four semantic types
1. regular Components (Vanilla obv)
2. singleton Components
2. hoistable components
3. resources
Each of these component types have their own rules related to mounting
and reconciliation however they are not direclty modeled as their own
unique fiber type. This is partly for code size but also because
reconciling the inner type of these components would be in a very hot
path in fiber creation and reconciliation and it's just not practical to
do this logic check here.
Right now we have three Fiber types used to implement these 4 concepts
but we probably need to reconsider the model and think of Host
Components as a single fiber type with an inner implementation. Once we
do this we can regularize things like transitioning between a resource
and a regular component or a singleton and a hoistable instance. The
cases where these transitions happen today aren't particularly common
but they can be observed and currently the handling of these transitions
is incomplete at best and buggy at worst. The most egregious case is the
link type. This can be a regular component (stylesheet without
precedence) a hoistable component (non stylesheet link tags) or a
resource (stylesheet with a precedence) and if you have a single jsx
slot that tries to reconcile transitions between these types it just
doesn't work well.
This commit adds an error for when a Hoistable goes from Instance to
Resource. Currently this is only possible for `<link>` elements going to
and from stylesheets with precedence. Hopefully we'll be able to remove
this error and implement as an inner type before we encounter new
categories for the Hoistable types
detecting type shifting to and from regular components is harder to do
efficiently because we don't want to reevaluate the type on every update
for host components which is currently not required and would add
overhead to a very hot path
singletons can't really type shift in their one practical implementation
(DOM) so they are only a problem in theroy not practice
Rick Hanlon
Ricky
Joe Savona
Niklas Mollenhauer
Sebastian Markbåge
Josh Story
Lauren Tan
Jan Kassens
Ruslan Lesiutin
XiaoPi
Vitali Zaidman
Dmytro Rykun
Batuhan Tomo
Jiachi Liu
Andrew Clark