Commit Graph

1011 Commits

Author SHA1 Message Date
lauren
64f89510af [crud] Enable on RTR FB builds (#31590) 2024-11-19 17:25:11 -05:00
lauren
7dd6b9e68a [crud] Add enableUseResourceEffectHook flag (#31556)
Adds a new feature flag for `enableUseResourceEffectHook`.

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/31556).
* #31523
* #31557
* __->__ #31556
* #31555
2024-11-15 17:49:42 -05:00
Andrew Clark
988e217670 Turn on enableSiblingPrerendering in canary (#31541)
In preparation for the next RC, I set this feature flag to true
everywhere. I did not delete the feature flag yet, in case there are yet
more bugs to be discovered.

I also didn't remove the dynamic feature flag from the Meta builds; I'll
let the Meta folks handle that.
2024-11-14 11:48:14 -05:00
Jan Kassens
682a103cde [www] set disableLegacyMode to true (#31439) 2024-11-07 09:05:31 -05:00
Jan Kassens
e1378902bb [string-refs] cleanup string ref code (#31443) 2024-11-06 14:00:10 -05:00
Jan Kassens
a7b83e7ceb [www] set disableStringRefs to true (#31438) 2024-11-06 12:13:43 -05:00
Jan Kassens
d1f04722d6 [string-refs] remove enableLogStringRefsProd flag (#31414)
We no longer need this production logging.
2024-11-06 09:00:49 -05:00
Sebastian Markbåge
156eab2f7b Fork the "empty" prepareStackTrace case for Server builds (#31427)
We don't actually want the source mapped version of `.stack` from errors
because that would cause us to not be able to associate it with a source
map in the UIs that need it. The strategy in browsers is more correct
where the display is responsible for source maps.

That's why we disable any custom `prepareStackTrace` like the ones added
by `source-map`. We reset it to `undefined`.

However, when running node with `--enable-source-maps` the default for
`prepareStackTrace` which is a V8 feature (but may exist elsewhere too
like Bun) is a source mapped version of the stack. In those environments
we need to reset it to a default implementation that doesn't apply
source maps.

We already did this in Flight using the `ReactFlightStackConfigV8.js`
config. However, we need this more generally in the
`shared/ReactComponentStackFrame` implementation.

We could always set it to the default implementation instead of
`undefined` but that's unnecessary code in browser builds and it might
lead to slightly different results. For safety and code size, this PR
does it with a fork instead.

All builds specific to `node` or `edge` (or `markup` which is a server
feature) gets the default implementation where as everything else (e.g.
browsers) get `undefined` since it's expected that this is not source
mapped. We don't have to do anything about the equivalent in React
DevTools since React DevTools doesn't run on the server.
2024-11-05 15:05:04 -05:00
Jan Kassens
07aa494432 Remove enableRefAsProp feature flag (#30346)
The flag is fully rolled out.
2024-11-04 14:30:58 -05:00
Josh Story
7c8e5e7ab8 Reenable lazy context propagation (#31405)
Reverts facebook/react#31403 to reenable lazy context propagation

The disabling was to produce a build that could help track down whether
this flag is causing a possibly related bug in transitions but we don't
intend to disable it just fix forward once we figure out what the
problem is
2024-11-01 15:17:51 -07:00
Josh Story
16409d0560 temporarily disable lazy context propagation (#31403)
disables lazy context propagation in oss to help determine if it is
causing bugs in startTransition. Will reenable after cutting a canary
release with this flag disabled
2024-11-01 15:16:26 -07:00
Sebastian Markbåge
b8ae38f88b Audit try/finally around console patching (#31286)
Otherwise if something errors they can be left patched.

[Review without
whitespace](https://github.com/facebook/react/pull/31286/files?w=1)
2024-10-18 12:05:20 -04:00
Jan Kassens
75dd053b5e [string-refs] make disableStringRefs a dynamic www flag (#31175) 2024-10-14 10:13:40 -04:00
Jan Kassens
5636fad840 [string-refs] log string ref from prod (#31161)
If passed as a feature flag, this calls the configured function when a
string ref is used even from prod code to find the last usages.
2024-10-10 18:12:47 -04:00
Jan Kassens
de43d560a8 [cleanup] remove flag enableAddPropertiesFastPath (#31062)
The experiment was tested internally and rolled out, replacing the flag
with `true`.
2024-10-09 16:46:35 -04:00
Jack Pope
d8c90fa48d Disable infinite render loop detection (#31088)
We're seeing issues with this feature internally including bugs with
sibling prerendering and errors that are difficult for developers to
action on. We'll turn off the feature for the time being until we can
improve the stability and ergonomics.

This PR does two things:
- Turn off `enableInfiniteLoopDetection` everywhere while leaving it as
a variant on www so we can do further experimentation.
- Revert https://github.com/facebook/react/pull/31061 which was a
temporary change for debugging. This brings the feature back to
baseline.
2024-10-01 11:00:57 -04:00
Sebastian Markbåge
654e387d7e [Flight] Serialize Server Components Props in DEV (#31105)
This allows us to show props in React DevTools when inspecting a Server
Component.

I currently drastically limit the object depth that's serialized since
this is very implicit and you can have heavy objects on the server.

We previously was using the general outlineModel to outline
ReactComponentInfo but we weren't consistently using it everywhere which
could cause some bugs with the parsing when it got deduped on the
client. It also lead to the weird feature detect of `isReactComponent`.
It also meant that this serialization was using the plain serialization
instead of `renderConsoleValue` which means we couldn't safely serialize
arbitrary debug info that isn't serializable there.

So the main change here is to call `outlineComponentInfo` and have that
always write every "Server Component" instance as outlined and in a way
that lets its props be serialized using `renderConsoleValue`.

<img width="1150" alt="Screenshot 2024-10-01 at 1 25 05 AM"
src="https://github.com/user-attachments/assets/f6e7811d-51a3-46b9-bbe0-1b8276849ed4">
2024-10-01 01:39:20 -04:00
Jack Pope
60b1420f18 Turn on lazy context propagation for RN and RTR (#31076)
Following https://github.com/facebook/react/pull/30935 let's turn this
on across the board so we can clean up experiments in RN.
2024-09-26 12:55:46 -04:00
Sebastian Markbåge
0eab377a96 Add enableComponentPerformanceTrack Flag (#30960)
This flag will be used to gate a new timeline profiler that's integrate
with the Performance Tab and the new performance.measure extensions in
Chrome.

It replaces the existing DevTools feature so this disables
enableSchedulingProfiler when it is enabled since they can interplay in
weird ways potentially.

This means that experimental React now disable scheduling profiler and
enables this new approach.
2024-09-16 11:09:40 -04:00
Jan Kassens
d3d4d3a46b Call cleanup of insertion effects when hidden (#30954)
Insertion effects do not unmount when a subtree is removed while
offscreen.

Current behavior for an insertion effect is if the component goes

- *visible -> removed:* calls insertion effect cleanup
- *visible -> offscreen -> removed:* insertion effect cleanup is never
called

This makes it so we always call insertion effect cleanup when removing
the component.

Likely also fixes https://github.com/facebook/react/issues/26670

---------

Co-authored-by: Rick Hanlon <rickhanlonii@fb.com>
2024-09-13 16:18:14 -04:00
Sebastian Markbåge
89b445709d Enable lazy context propagation (#30935)
Last I heard this was great so not sure there are any more blockers to
just include it in 19?
2024-09-12 13:01:56 -04:00
Josh Story
94e652d505 disable enableSiblingPrerendering in experimental channel (#30952)
Disables `enableSiblingPrerendering` in the experimental builds until
the feature is tested at Meta first.
2024-09-12 09:33:20 -07:00
Sebastian Markbåge
4f60494156 [Flight] Ship DEV-only enableServerComponentLogs flag in Stable/Canary (#30847)
To recap. This only affects DEV and RSC. It patches console on the
server in DEV (similar to how React DevTools already does and what we
did for the double logging). Then replays those logs with a `[Server]`
badge on the client so you don't need a server terminal open.

This has been on for over 6 months now in our experimental channel and
we've had a lot of coverage in Next.js due to various experimental flags
like taint and ppr.

It's non-invasive in that even if something throws we just serialize
that as an unknown value.

The main feedback we've gotten was:

- The serialization depth wasn't deep enough which I addressed in #30294
and haven't really had any issues since. This could still be an issue or
the inverse that you serialize too many logs that are also too deep.
This is not so much an issue with intentional logging and things like
accidental errors don't typically have unbounded arguments (e.g. React
errors are always string arguments). The ideal would be some way to
retain objects and then load them on-demand but that needs more
plumbing. Which can be later.
- The other was that double logging on the server is annoying if the
same terminal does both the RSC render and SSR render which was
addressed in #30207. It is now off by default in node/edge-builds of the
client, on by default in browser builds. With the `replayConsole` option
to either opt-in or out.

We've reached a good spot now I think.

These are better with `enableOwnerStacks` but that's a separate track
and not needed.

The only thing to document here, other than maybe that we're doing it,
is the `replayConsole` option but that's part of the RSC renderers that
themselves are not documented so nowhere to document it.
2024-08-30 15:11:57 -04:00
Benoit Girard
246d7bfeb0 Enable suspenseCallback on React Native (#29210)
## Summary

suspenseCallback feature has proved to be useful for FB Web. Let's look
at enabling the feature for the React Native build.


## How did you test this change?

Will sync the react changes with a React Native build and will verify
that performance logging is correctly notified of suspense promises
during the suspense callback.
2024-08-26 22:06:02 -04:00
Andrew Clark
eb3ad065a1 Feature flag: enableSiblingPrerendering (#30761)
Adds a new feature flag for an upcoming experiment.

No implementation yet.
2024-08-22 10:17:19 -04:00
Josh Story
7b41cdc093 [Flight][Static] Implement halting a prerender behind enableHalt (#30705)
enableHalt turns on a mode for flight prerenders where aborts are
treated like infinitely stalled outcomes while still completing the
prerender. For regular tasks we simply serialize the slot as a promise
that never settles. For ReadableStream, Blob, and Async Iterators we
just never advance the serialization so they remain unfinished when
consumed on the client.

When enableHalt is turned on aborts of prerenders will halt rather than
error. The abort reason is forwarded to the upstream produces of the
aforementioned async iterators, blobs, and ReadableStreams. In the
future if we expose a signal that you can consume from within a render
to cancel additional work the abort reason will also be forwarded there
2024-08-16 14:21:57 -07:00
Sebastian Markbåge
19bd26beb6 [Flight/DevTools] Pass the Server Component's "key" as Part of the ReactComponentInfo (#30703)
Supports showing the key in DevTools on the Server Component that the
key was applied to. We can also use this to reconcile to preserve
instance equality when they're reordered.

One thing that's a bit weird about this is that if you provide an
explicit key on a Server Component that alone doesn't have any
semantics. It's because we pass the key down and let the nearest child
inherit the key or get prefixed by the key.

So you might see the same key as a prefix on the child of the Server
Component too which might be a bit confusing. We could remove the prefix
from children but that might also be a bit confusing if they collide.

The div in this case doesn't have a key explicitly specified. It gets it
from the Server Component parent.

<img width="1107" alt="Screenshot 2024-08-14 at 10 06 36 PM"
src="https://github.com/user-attachments/assets/cfc517cc-e737-44c3-a1be-050049267ee2">

Overall keys get a bit confusing when you apply filter. Especially since
it's so common to actually apply the key on a Host Instance. So you
often don't see the key.
2024-08-15 11:04:53 -04:00
Jan Kassens
65903583d2 Remove flag enableUseDeferredValueInitialArg (#30595)
This is enabled everywhere for a while and I don't think we'd be backing
this out of 19. Seems like it's good to clean up to me.
2024-08-05 11:25:05 -04:00
Jan Kassens
5fb67fa25c Cloned flag to avoid extra clones in persistent renderer (#27647)
Persistent renderers used the `Update` effect flag to check if a subtree
needs to be cloned. In some cases, that causes extra renders, such as
when a layout effect is triggered which only has an effect on the JS
side, but doesn't update the host components.

It's been a bit tricky to find the right places where this needs to be
set and I'm not 100% sure I got all the cases even though the tests
passed.
2024-08-01 15:11:19 -04:00
Sebastian Markbåge
12e9579099 [Flight] Enable owner stacks on the client when replaying logs (#30473)
There's a special case that happens when we replay logs on the client
because this doesn't happen within the context of any particular
rendered component. So we need to reimplement things that would normally
be handled by a full client like Fiber.

The implementation of `getOwnerStackByComponentInfoInDev` is the
simplest version since it doesn't have any client components in it so I
move it to `shared/`. It's only used by Flight but both `react-server/`
and `react-client/` packages. The ReactComponentInfo type is also more
generic than just Flight anyway.

In a follow up I still need to implement this in React DevTools when
native tasks are not available so that it appends it to the console.
2024-07-31 07:56:15 -04:00
Jack Pope
3f8b1333da Set enableLazyContextPropagation to dynamic on RN (#30516) 2024-07-30 18:31:31 -04:00
Jan Kassens
6b82f3c904 [RN] experiment to move Fabric completeWork to the commit phase (#30513)
There is currently a mismatch in how the persistent mode JS API and the
Fabric native code interpret `completeRoot`.

This is a short-lived experiment to see the effect of moving the Fabric
`completeRoot` call from `finalizeContainerChildren` to
`replaceContainerChildren` which in some cases does not get called.
2024-07-29 18:38:55 -04:00
Jack Pope
397646ad51 Update enableLazyContextPropagation flag (#30514)
- Flag set to true for FB
- Flag set to experimental for OSS
2024-07-29 16:50:28 -04:00
Jack Pope
1350a85980 Add unstable context bailout for profiling (#30407)
**This API is not intended to ship. This is a temporary unstable hook
for internal performance profiling.**

This PR exposes `unstable_useContextWithBailout`, which takes a compare
function in addition to Context. The comparison function is run to
determine if Context propagation and render should bail out earlier.
`unstable_useContextWithBailout` returns the full Context value, same as
`useContext`.

We can profile this API against `useContext` to better measure the cost
of Context value updates and gather more data around propagation and
render performance.

The bailout logic and test cases are based on
https://github.com/facebook/react/pull/20646

Additionally, this implementation allows multiple values to be compared
in one hook by returning a tuple to avoid requiring additional Context
consumer hooks.
2024-07-26 14:38:24 -04:00
Jack Pope
14a4699ff1 Remove allowConcurrentByDefault flag (#30445)
Following https://github.com/facebook/react/pull/30436

Concurrent by default strategy has been unshipped. Here we clean up the
`allowConcurrentByDefault` path and related logic/tests.

For now, this keeps the `concurrentUpdatesByDefaultOverride` argument in
`createContainer` and `createHydrationContainer` and ignores the value
to prevent more breaking changes to `react-reconciler` in the RC stage.
2024-07-25 11:59:50 -04:00
Sebastian Markbåge
5b37af7daa Stop filtering owner stacks (#30438)
We still filter them before passing from server to client in Flight
Server but when presenting a native stack, we don't need to filter them.
That's left to ignore listing in the presentation.

The stacks are pretty clean regardless thanks to the bottom stack
frames.

We can also unify the owner stack formatters into one shared module
since Fizz/Flight/Fiber all do the same thing. DevTools currently does
the same thing but is forked so it can support multiple versions.
2024-07-24 13:01:07 -04:00
Jack Pope
e902c45caf Remove forceConcurrentByDefaultForTesting flag (#30436)
Concurrent by default has been unshipped! Let's clean it up.

Here we remove `forceConcurrentByDefaultForTesting`, which allows us to
run tests against both concurrent strategies. In the next PR, we'll
remove the actual concurrent by default code path.
2024-07-24 10:17:33 -04:00
Jan Kassens
b7e7f1a3fa [BE] upgrade prettier to 3.3.3 (#30420)
Mostly just changes in ternary formatting.
2024-07-22 16:09:01 -04:00
Jan Kassens
d025ddd3b9 Set enableFastJSX flag to true (#30343)
When these to diffs are landed, we can merge this

- [x] D59772879
- [x] D59773043
2024-07-22 11:50:35 -04:00
Sebastian Markbåge
06763852de [Flight] Parse Stack on the Server and Transfer Structured Stack (#30410)
Stacked on #30401.

Previously we were transferring the original V8 stack trace string to
the client and then parsing it there. However, really the server is the
one that knows what format it is and it should be able to vary by server
environment.

We also don't use the raw string anymore (at least not in
enableOwnerStacks). We always create the native Error stacks.

The string also made it unclear which environment it is and it was
tempting to just use it as is.

Instead I parse it on the server and make it a structured stack in the
transfer format. It also makes it clear that it needs to be formatted in
the current environment before presented.
2024-07-22 11:18:55 -04:00
Sebastian Markbåge
b15c1983dc [Flight] Normalize Stack Using Fake Evals (#30401)
Stacked on https://github.com/facebook/react/pull/30400 and
https://github.com/facebook/react/pull/30369

Previously we were using fake evals to recreate a stack for console
replaying and thrown errors. However, for owner stacks we just used the
raw string that came from the server.

This means that the format of the owner stack could include different
formats. Like Spidermonkey format for the client components and V8 for
the server components. This means that this stack can't be parsed
natively by the browser like when printing them as error like in
https://github.com/facebook/react/pull/30289. Additionally, since
there's no source file registered with that name and no source mapping
url, it can't be source mapped.

Before:

<img width="1329" alt="before-firefox"
src="https://github.com/user-attachments/assets/cbe03f9c-96ac-48fb-b58f-f3a224a774f4">

Instead, we need to create a fake stack like we do for the other things.
That way when it's printed as an Error it gets source mapped. It also
means that the format is consistently in the native format of the
current browser.

After:

<img width="753" alt="after-firefox"
src="https://github.com/user-attachments/assets/b436f1f5-ca37-4203-b29f-df9828c9fad3">

So this is nice because you can just take the result from
`captureOwnerStack()` and append it to an `Error` stack and print it
natively. E.g. this is what React DevTools will do.

If you want to parse and present it yourself though it's a bit awkward
though. The `captureOwnerStack()` API now includes a bunch of
`rsc://React/` URLs. These don't really have any direct connection to
the source map. Only the browser knows this connection from the eval.
You basically have to strip the prefix and then manually pass the
remainder to your own `findSourceMapURL`.

Another awkward part is that since Safari doesn't support eval sourceURL
exposed into `error.stack` - it means that `captureOwnerStack()` get an
empty location for server components since the fake eval doesn't work
there. That's not a big deal since these stacks are already broken even
for client modules for many because the `eval-source-map` strategy in
Webpack doesn't work in Safari for this same reason.

A lot of this refactoring is just clarifying that there's three kind of
ReactComponentInfo fields:

- `stack` - The raw stack as described on the original server.
- `debugStack` - The Error object containing the stack as represented in
the current client as fake evals.
- `debugTask` - The same thing as `debugStack` but described in terms of
a native `console.createTask`.
2024-07-22 11:03:15 -04:00
Jan Kassens
1d5a208fda [native-fb] set disableDefaultPropsExceptForClasses flag to true (#30339)
Reflecting D59402048
2024-07-15 14:20:40 -04:00
Jan Kassens
fc1371f6bf [native-fb] set consoleManagedByDevToolsDuringStrictMode flag to true (#30338)
Reflecting D59232098.
2024-07-15 12:31:17 -04:00
Sebastian Markbåge
ff89ba7346 Disable consoleWithStackDev Transform except in RN/WWW (#30313)
Stacked on #30308.

This is now a noop module so we can stop applying the transform of
console.error using the Babel plugin in the mainline builds. I'm keeping
the transform for RN/WWW for now although it might be nice if the
transform moved into those systems as it gets synced instead of keeping
it upstream.

In jest tests we're already not running the forks for RN/WWW so we don't
need it at all there.
2024-07-12 14:39:38 -04:00
Sebastian Markbåge
400e822277 Remove Component Stack from React Logged Warnings and Error Reporting (#30308)
React transpiles some of its own `console.error` calls into a helper
that appends component stacks to those calls. However, this doesn't
cover user space `console.error` calls - which includes React helpers
that React has moved into third parties like createClass and prop-types.

The idea is that any user space component can add a warning just like
React can which is why React DevTools adds them too if they don't
already exist. Having them appended in both places is tricky because now
you have to know whether to remove them from React's logs.

Similarly it's often common for server-side frameworks to forget to
cover the `console.error` logs from other sources since React DevTools
isn't active there. However, it's also annoying to get component stacks
clogging the terminal - depending on where the log came from.

In the future `console.createTask()` will cover this use case natively
and when available we don't append them at all.

The new strategy relies on either:

- React DevTools existing to add them to React logs as well as third
parties.
- `console.createTask` being supported and surfaced.
- A third party framework showing the component stack either in an Error
Dialog or appended to terminal output.

For a third party to be able to implement this they need to be able to
get the component stack. To get the component stack from within a
`console.error` call you need to use the `React.captureOwnerStack()`
helper which is only available in `enableOwnerStacks` flag. However,
it's possible to polyfill with parent stacks using internals as a stop
gap. There's a question of whether React 19 should just go out with
`enableOwnerStacks` to expose this but regardless I think it's best it
doesn't include component stacks from the runtime for consistency.

In practice it's not really a regression though because typically either
of the other options exists and error dialogs don't implement
`console.error` overrides anyway yet. SSR terminals might miss them but
they'd only have them in DEV warnings to begin with an a subset of React
warnings. Typically those are either going to happen on the client
anyway or replayed.

Our tests are written to assert that component stacks work in various
scenarios all over the place. To ensure that this keeps working I
implement a "polyfill" that is similar to that expected a server
framework might do - in `assertConsoleErrorDev` and `toErrorDev`.

This PR doesn't yet change www or RN since they have their own forks of
consoleWithStackDev for now.
2024-07-12 13:02:22 -04:00
Lauren Tan
ff3f1fac65 [RN] Set enableOwnerStacks and enableUseDeferredValueInitialArg to false
In www, the experimental versions get a .modern.js or .classic.js prefix
and get copied into the same folder. In RN, they don't seem to have
.modern.js and .classic.js versions so they end up getting the same
name.

sebmarkbage's theory is that what happens is that they then override
the file that was already there. So depending on if experimental or
stable build finishes first you get a different version at the end.

It doesn't make sense to use `__EXPERIMENTAL__` for flags in native-fb
since there's no modern/classic split there. So that flag should just be
hardcoded to true or false and then it doesn't matter which one finishes
first.

We don't support experimental builds in OSS RN neither so the same thing
could happen with
[`enableOwnerStacks`](5dcf3ca8d4/packages/shared/forks/ReactFeatureFlags.native-oss.js (L60)).

You can see that the build errors in the previous PR but passes after
these flag changes.

ghstack-source-id: d10f37bcea
Pull Request resolved: https://github.com/facebook/react/pull/30322
2024-07-12 12:11:50 -04:00
Sebastian Markbåge
433068eece Remove top stack frame from getCurrentStack (#30306)
The full stack is the current execution stack (`new Error().stack`) +
the current owner stack (`React.captureOwnerStack()`).

The idea with the top frame was that when we append it to console.error
we'd include both since otherwise the true reason would be obscured
behind the little `>` to expand. So we'd just put both stack front and
center. By adding this into getCurrentStack it was easy to use the same
filtering. I never implemented in Fizz or Flight though.

However, with the public API `React.captureOwnerStack()` it's not
necessary to include the current stack since you already have it and
you'd have filtering capabilities in user space too.

Since I'm removing the component stacks from React itself we no longer
need this. It's expected that maybe RDT or framework polyfill would
include this same technique though.
2024-07-11 18:34:41 -04:00
Jan Kassens
af28f480e8 Feature flag to disable legacy context for function components (#30319)
While the goal is to remove legacy context completely, I think we can
already land the removal of legacy context for function components. I
didn't even know this feature existed until reading the code recently.

The win is just a couple of property lookups on function renders, but it
trims down the API already as the full removal will likely still take a
bit more time.

www: Starting with enabled test renderer and a feature flag for
production rollout.

RN: Not enabled, will follow up on this.
2024-07-11 16:21:12 -04:00
Sebastian Markbåge
85acf2d195 Delete suppressWarning in OSS (#30312)
I'm pretty sure this is completely unnecessary even in www and RN
because it's only useful if you use the mock scheduler which typically
only we do in our own tests. But all our tests pass so unless www/RN
does something with it, I don't think this is used.

Also remove unnecessary `__DEV__` check. If it gets pulled in prod, we'd
want to know about it.
2024-07-11 11:20:42 -04:00
Jan Kassens
fe9828954a Experiment with using an object literal for Fiber creation (#28734)
Object literals should be faster at least on React Native with Hermes as
the JS engine.
It might also be interesting to confirm the old comments in this file
from years ago are even still valid. Creating an object from a literal
should be a simpler operation.

It's a bit unfortunate that this introduces a bunch of copied code, but
since we rearely update the fields on fibers, this seems like an okay
tradeoff for a hot code path. An alternative would be some sort of macro
system, but that doesn't seem worth the extra complexity.
2024-07-10 16:42:08 -04:00