Commit Graph

20446 Commits

Author SHA1 Message Date
Joe Savona a73ebbde59 Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-30 16:29:29 -07:00
Joe Savona 19b3694f7e Update base for Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-30 16:29:28 -07:00
Joe Savona ac00108330 Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-30 15:56:53 -07:00
Joe Savona 7a77e78e4a Update base for Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-30 15:56:52 -07:00
Joe Savona c00f41b8e2 Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-30 11:33:20 -07:00
Joe Savona 786d8bf2af Update base for Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-30 11:33:19 -07:00
Joe Savona 3f32fbc6a6 Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-29 17:30:20 -07:00
Joe Savona 97e2e6ca77 Update base for Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-29 17:30:20 -07:00
Joe Savona 8e1547b23a Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-28 22:27:14 -07:00
Joe Savona 905a787d26 Update base for Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-28 22:27:13 -07:00
Joe Savona 2b5443e6d0 Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-28 17:38:41 -07:00
Joe Savona 2b88127709 Update base for Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-28 17:38:41 -07:00
Joe Savona 785b412743 Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-28 16:29:28 -07:00
Joe Savona 2dad41e7ba Update base for Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-28 16:29:27 -07:00
Joe Savona f9bb6067ab Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-28 15:42:36 -07:00
Joe Savona 94409c39f3 Update base for Update on "[compiler] Improve inference of function expression mutation/aliasing effects"
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-28 15:42:35 -07:00
Joe Savona e8d39119b1 [compiler] Improve inference of function expression mutation/aliasing effects
Distinguish the various forms of mutation, and do basic replaying of these effects when the function is created (imperfect, temporary).

[ghstack-poisoned]
2025-05-27 16:31:02 -07:00
Joe Savona ff14c671fd Update on "[compiler] Alternate pipeline for new mutability model"
This PR gets a first fixture working end-to-end with the new mutability and aliasing model. Key changes:

* Add a feature flag to enable the model. When enabled we no longer call InferReferenceEffects or InferMutableRanges, and instead use the new equivalents.
* Adds a pass that infers Place-specific effects based on mutable ranges and instruction effects. This is necessary to satisfy existing code that requires operand effects to be populated.
* Adds a pass that infers the outwardly-visible capturing/aliasing behavior of a function expression. The idea is that this can bubble up and be used in conjunction with the `Apply` effect to get precise inference of things like `array.map(() => { ... })`.

[ghstack-poisoned]
2025-05-27 16:31:00 -07:00
Joe Savona ca0f0e006d Update base for Update on "[compiler] Alternate pipeline for new mutability model"
This PR gets a first fixture working end-to-end with the new mutability and aliasing model. Key changes:

* Add a feature flag to enable the model. When enabled we no longer call InferReferenceEffects or InferMutableRanges, and instead use the new equivalents.
* Adds a pass that infers Place-specific effects based on mutable ranges and instruction effects. This is necessary to satisfy existing code that requires operand effects to be populated.
* Adds a pass that infers the outwardly-visible capturing/aliasing behavior of a function expression. The idea is that this can bubble up and be used in conjunction with the `Apply` effect to get precise inference of things like `array.map(() => { ... })`.

[ghstack-poisoned]
2025-05-27 16:30:59 -07:00
Joe Savona 05a8b6a717 [compiler] Alternate pipeline for new mutability model
This PR gets a first fixture working end-to-end with the new mutability and aliasing model. Key changes:

* Add a feature flag to enable the model. When enabled we no longer call InferReferenceEffects or InferMutableRanges, and instead use the new equivalents.
* Adds a pass that infers Place-specific effects based on mutable ranges and instruction effects. This is necessary to satisfy existing code that requires operand effects to be populated.
* Adds a pass that infers the outwardly-visible capturing/aliasing behavior of a function expression. The idea is that this can bubble up and be used in conjunction with the `Apply` effect to get precise inference of things like `array.map(() => { ... })`.

[ghstack-poisoned]
2025-05-27 14:23:38 -07:00
Joe Savona 58e449ee0e [compiler] Add HIRFunction.returns: Place
[ghstack-poisoned]
2025-05-27 14:23:33 -07:00
Joe Savona 61bd21cd18 Update on "[compiler] Foundation of new mutability and aliasing (alternate take)"
Alternate take at a new mutability and alising model, aiming to replace `InferReferenceEffects` and `InferMutableRanges`. My initial passes at this were more complicated than necessary, and I've iterated to refine and distill this down to the core concepts. There are two effects that track information flow: `capture` and `alias`:

* Given distinct values A and B. After capture A -> B, mutate(B) does *not* modify A. This more precisely captures the semantic of the previous `Store` effect. As an example, `array.push(item)` has the effect `capture item -> array` and `mutate(array)`. The array is modified, not the item.
* Given distinct values A and B. After alias A -> B, mutate(B) *does* modify A. This is because B now refers to the same value as A.
* Given distinct values A and B, after *either* capture A -> B *or* alias A -> B, transitiveMutate(B) counts as a mutation of A. Transitive mutation is the default, and places that previously used `Store` will use non-transitive mutate effects instead.

Conceptually "capture A -> B" means that a reference to A was "captured" (or stored) within A, but there is not a directly aliasing. Whereas "alias A -> B" means literal value aliasing.

The idea is that our previous sequential fixpoint loops in InferMutableRanges can instead work by first looking at transitive mutations, then look at non-transitive mutations. And aliasing groups can be built purely based on the `alias` effect.

Lots more to do here but the structure is coming together.

[ghstack-poisoned]
2025-05-27 14:23:31 -07:00
Joe Savona 3e67c7e39f Update base for Update on "[compiler] Foundation of new mutability and aliasing (alternate take)"
Alternate take at a new mutability and alising model, aiming to replace `InferReferenceEffects` and `InferMutableRanges`. My initial passes at this were more complicated than necessary, and I've iterated to refine and distill this down to the core concepts. There are two effects that track information flow: `capture` and `alias`:

* Given distinct values A and B. After capture A -> B, mutate(B) does *not* modify A. This more precisely captures the semantic of the previous `Store` effect. As an example, `array.push(item)` has the effect `capture item -> array` and `mutate(array)`. The array is modified, not the item.
* Given distinct values A and B. After alias A -> B, mutate(B) *does* modify A. This is because B now refers to the same value as A.
* Given distinct values A and B, after *either* capture A -> B *or* alias A -> B, transitiveMutate(B) counts as a mutation of A. Transitive mutation is the default, and places that previously used `Store` will use non-transitive mutate effects instead.

Conceptually "capture A -> B" means that a reference to A was "captured" (or stored) within A, but there is not a directly aliasing. Whereas "alias A -> B" means literal value aliasing.

The idea is that our previous sequential fixpoint loops in InferMutableRanges can instead work by first looking at transitive mutations, then look at non-transitive mutations. And aliasing groups can be built purely based on the `alias` effect.

Lots more to do here but the structure is coming together.

[ghstack-poisoned]
2025-05-27 14:23:31 -07:00
Joe Savona 6cc26518f3 Update on "[compiler] Foundation of new mutability and aliasing (alternate take)"
Alternate take at a new mutability and alising model, aiming to replace `InferReferenceEffects` and `InferMutableRanges`. My initial passes at this were more complicated than necessary, and I've iterated to refine and distill this down to the core concepts. There are two effects that track information flow: `capture` and `alias`:

* Given distinct values A and B. After capture A -> B, mutate(B) does *not* modify A. This more precisely captures the semantic of the previous `Store` effect. As an example, `array.push(item)` has the effect `capture item -> array` and `mutate(array)`. The array is modified, not the item.
* Given distinct values A and B. After alias A -> B, mutate(B) *does* modify A. This is because B now refers to the same value as A.
* Given distinct values A and B, after *either* capture A -> B *or* alias A -> B, transitiveMutate(B) counts as a mutation of A. Transitive mutation is the default, and places that previously used `Store` will use non-transitive mutate effects instead.

Conceptually "capture A -> B" means that a reference to A was "captured" (or stored) within A, but there is not a directly aliasing. Whereas "alias A -> B" means literal value aliasing.

The idea is that our previous sequential fixpoint loops in InferMutableRanges can instead work by first looking at transitive mutations, then look at non-transitive mutations. And aliasing groups can be built purely based on the `alias` effect.

Lots more to do here but the structure is coming together.

[ghstack-poisoned]
2025-05-23 16:58:18 -07:00
Joe Savona 79a13a29c5 Update base for Update on "[compiler] Foundation of new mutability and aliasing (alternate take)"
Alternate take at a new mutability and alising model, aiming to replace `InferReferenceEffects` and `InferMutableRanges`. My initial passes at this were more complicated than necessary, and I've iterated to refine and distill this down to the core concepts. There are two effects that track information flow: `capture` and `alias`:

* Given distinct values A and B. After capture A -> B, mutate(B) does *not* modify A. This more precisely captures the semantic of the previous `Store` effect. As an example, `array.push(item)` has the effect `capture item -> array` and `mutate(array)`. The array is modified, not the item.
* Given distinct values A and B. After alias A -> B, mutate(B) *does* modify A. This is because B now refers to the same value as A.
* Given distinct values A and B, after *either* capture A -> B *or* alias A -> B, transitiveMutate(B) counts as a mutation of A. Transitive mutation is the default, and places that previously used `Store` will use non-transitive mutate effects instead.

Conceptually "capture A -> B" means that a reference to A was "captured" (or stored) within A, but there is not a directly aliasing. Whereas "alias A -> B" means literal value aliasing.

The idea is that our previous sequential fixpoint loops in InferMutableRanges can instead work by first looking at transitive mutations, then look at non-transitive mutations. And aliasing groups can be built purely based on the `alias` effect.

Lots more to do here but the structure is coming together.

[ghstack-poisoned]
2025-05-23 16:58:17 -07:00
Joe Savona 80ae4e96ae [compiler] Foundation of new mutability and aliasing (alternate take)
Alternate take at a new mutability and alising model, aiming to replace `InferReferenceEffects` and `InferMutableRanges`. My initial passes at this were more complicated than necessary, and I've iterated to refine and distill this down to the core concepts. There are two effects that track information flow: `capture` and `alias`:

* Given distinct values A and B. After capture A -> B, mutate(B) does *not* modify A. This more precisely captures the semantic of the previous `Store` effect. As an example, `array.push(item)` has the effect `capture item -> array` and `mutate(array)`. The array is modified, not the item.
* Given distinct values A and B. After alias A -> B, mutate(B) *does* modify A. This is because B now refers to the same value as A.
* Given distinct values A and B, after *either* capture A -> B *or* alias A -> B, transitiveMutate(B) counts as a mutation of A.

Conceptually "capture A -> B" means that a reference to A was "captured" (or stored) within A, but there is not a directly aliasing. Whereas "alias A -> B" means literal value aliasing.

The idea is that our previous sequential fixpoint loops in InferMutableRanges can instead work by first looking at transitive mutations, then look at non-transitive mutations. And aliasing groups can be built purely based on the `alias` effect.

Lots more to do here but the structure is coming together.

[ghstack-poisoned]
2025-05-22 16:57:29 -07:00
Joe Savona f5cd556ffa Update on "[compiler] Repro for imprecise memo due to closure capturing changes"
Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable.

The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation.

[ghstack-poisoned]
2025-05-22 16:57:27 -07:00
Joe Savona 0c7e645dd3 Update base for Update on "[compiler] Repro for imprecise memo due to closure capturing changes"
Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable.

The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation.

[ghstack-poisoned]
2025-05-22 16:57:26 -07:00
Sebastian Markbåge 5dc1b212c3 [Fizz] Support basic SuspenseList forwards/backwards revealOrder (#33306)
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>
2025-05-19 15:16:42 -04:00
Jan Kassens a3abf5f2f8 [eslint-plugin-react-hooks] add experimental_autoDependenciesHooks option (#33294) 2025-05-19 15:08:30 -04:00
Sebastian Markbåge 462d08f9ba Move SuspenseListProps into a shared/ReactTypes (#33298)
So they can be shared by server. Incorporates the types from definitely
typed too.
2025-05-17 20:00:56 -04:00
Sebastian Markbåge 6060367ef8 [Fizz] Wrap revealCompletedBoundaries in a ViewTransitions aware version (#33293)
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.
2025-05-17 18:18:24 -04:00
Sebastian Markbåge c250b7d980 [Fizz] Should be considered complete inside onShellReady callback (#33295)
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.
2025-05-16 14:53:40 -04:00
Jan Kassens 4448b18760 [eslint-plugin-react-hooks] fix exhaustive deps lint rule with component syntax (#33182) 2025-05-15 12:51:18 -04:00
Ricky 4a45ba92c4 [sync] Fix noop for xplat (#33214)
Noop detection for xplat syncs broke because `eslint-plugin-react-hooks`
uses versions like:

- `0.0.0-experimental-d85f86cf-20250514`

But xplat expects them to be of the form:

- `19.2.0-native-fb-63d664b2-20250514`

This PR fixes the noop by ignoring
`eslint-plugin-react-hooks/package.json` changes. This means we won't
create a sync if only that package.json changes, but that should be rare
and we can follow up with better detection if needed.

[Example failed
action](https://github.com/facebook/react/actions/runs/15032346805/job/42247414406):

<img width="1031" alt="Screenshot 2025-05-15 at 11 31 17 AM"
src="https://github.com/user-attachments/assets/d902079c-1afe-4e18-af1d-25e60e28929e"
/>

I believe the regression was caused by
https://github.com/facebook/react/pull/33104
2025-05-15 12:12:51 -04:00
lauren 08cb2d7ee7 [ci] Log author_association (#33213)
For debugging purposes, log author_association
2025-05-15 11:49:56 -04:00
lauren 203df2c940 [compiler] Update changelog for 19.1.0-rc.2 (#33207)
Update the changelog.
2025-05-15 10:34:11 -04:00
Sebastian Markbåge 65b5aae010 [Fizz] Add vt- prefix attributes to annotate <ViewTransition> in HTML (#33206)
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.
2025-05-15 01:04:10 -04:00
Sebastian Markbåge 3f67d0857e [Fizz] Track whether we're in a fallback on FormatContext (#33194)
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.
2025-05-15 00:06:06 -04:00
Sebastian Markbåge 96eb84e493 Claim the useId name space for every auto named ViewTransition (#33200)
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.
2025-05-14 17:52:41 -04:00
Sebastian Markbåge 63d664b220 Don't consider Portals animating unless they're wrapped in a ViewTransition (#33191)
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.
2025-05-14 17:50:56 -04:00
Jan Kassens d85f86cf01 Delete stray file (#33199)
Not sure where this was coming from.
2025-05-14 11:27:36 -04:00
Sebastian Markbåge 3a5b326d81 [Fiber] Trigger default indicator for isomorphic async actions with no root associated (#33190)
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.
2025-05-13 16:10:28 -04:00
Sebastian Markbåge 59440424d0 Implement Navigation API backed default indicator for DOM renderer (#33162)
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.
2025-05-13 16:00:38 -04:00
Sebastian Markbåge b480865db0 [Fiber] Always flush Default priority in the microtask if a Transition was scheduled (#33186)
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.
2025-05-13 15:52:44 -04:00
Sebastian Markbåge 62d3f36ea7 [Fiber] Trigger default transition indicator if needed (#33160)
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
2025-05-13 15:45:11 -04:00
Sebastian Markbåge 0cac32d60d [Fiber] Stash the entangled async action lane on currentEventTransitionLane (#33188)
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.
2025-05-13 15:20:59 -04:00
Sebastian Markbåge 676f0879f3 Reset currentEventTransitionLane after flushing sync work (#33159)
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.
2025-05-13 15:18:02 -04:00
Sebastian Markbåge 997c7bc930 [DevTools] Get source location from structured callsites in prepareStackTrace (#33143)
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.
2025-05-13 12:39:10 -04:00
Sebastian Markbåge b94603b955 [Fizz] Gate rel="expect" behind enableFizzBlockingRender (#33183)
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.
2025-05-13 10:17:53 -04:00