Only with the enableOwnerStacks flag (which is not on in www).
This is a new DEV-only API to be able to implement what we do for
console.error in user space.
This API does not actually include the current stack that you'd get from
`new Error().stack`. That you'd have to add yourself.
This adds the ability to have conditional development exports because we
plan on eventually having separate ESM builds that use the "development"
or "production" export conditions.
NOTE: This removes the export of `act` from `react` in prod (as opposed
to a function that throws) - inline with what we do with other
conditional exports.
Basically make `console.error` and `console.warn` behave like normal -
when a component stack isn't appended. I need this because I need to be
able to print rich logs with the component stack option and to be able
to disable instrumentation completely in `console.createTask`
environments that don't need it.
Currently we can't print logs with richer objects because they're
toString:ed first. In practice, pretty much all arguments we log are
already toString:ed so it's not necessary anyway. Some might be like a
number. So it would only be a problem if some environment can't handle
proper consoles but then it's up to that environment to toString it
before logging.
The `Warning: ` prefix is historic and is both noisy and confusing. It's
mostly unnecessary since the UI surrounding `console.error` and
`console.warn` tend to have visual treatment around it anyway. However,
it's actively misleading when `console.error` gets prefixed with a
Warning that we consider an error level. There's an argument to be made
that some of our `console.error` don't make the bar for an error but
then the argument is to downgrade each of those to `console.warn` - not
to brand all our actual error logging with `Warning: `.
Apparently something needs to change in React Native before landing this
because it depends on the prefix somehow which probably doesn't make
sense already.
## Overview
Updates `eslint-plugin-jest` and enables the recommended rules with some
turned off that are unhelpful.
The main motivations is:
a) we have a few duplicated tests, which this found an I deleted
b) making sure we don't accidentally commit skipped tests
This disables symbol renaming in production builds. The original
variable and function names are preserved. All other forms of
compression applied by Closure (dead code elimination, inlining, etc)
are unchanged — the final program is identical to what we were producing
before, just in a more readable form.
The motivation is to make it easier to debug React issues that only
occur in production — the same reason we decided to start shipping
sourcemaps in #28827 and #28827.
However, because most apps run their own minification step on their npm
dependencies, it's not necessary for us to minify the symbols before
publishing — it'll be handled the app, if desired.
This is the same strategy Meta has used to ship React for years. The
React build itself has unminified symbols, but they get minified as part
of Meta's regular build pipeline.
Even if an app does not minify their npm dependencies, gzip covers most
of the cost of symbol renaming anyway.
This saves us from having to ship sourcemaps, which means even apps that
don't have sourcemaps configured will be able to debug the React build
as easily as they would any other npm dependency.
In React 19 React will finally stop publishing UMD builds. This is
motivated primarily by the lack of use of UMD format and the added
complexity of maintaining build infra for these releases. Additionally
with ESM becoming more prevalent in browsers and services like esm.sh
which can host React as an ESM module there are other options for doing
script tag based react loading.
This PR removes all the UMD build configs and forks.
There are some fixtures that still have references to UMD builds however
many of them already do not work (for instance they are using legacy
features like ReactDOM.render) and rather than block the removal on
these fixtures being brought up to date we'll just move forward and fix
or removes fixtures as necessary in the future.
This updates the behavior of form actions to automatically reset the
form's uncontrolled inputs after the action finishes.
This is a frequent feature request for people using actions and it
aligns the behavior of client-side form submissions more closely with
MPA form submissions.
It has no impact on controlled form inputs. It's the same as if you
called `form.reset()` manually, except React handles the timing of when
the reset happens, which is tricky/impossible to get exactly right in
userspace.
The reset shouldn't happen until the UI has updated with the result of
the action. So, resetting inside the action is too early.
Resetting in `useEffect` is better, but it's later than ideal because
any effects that run before it will observe the state of the form before
it's been reset.
It needs to happen in the mutation phase of the transition. More
specifically, after all the DOM mutations caused by the transition have
been applied. That way the `defaultValue` of the inputs are updated
before the values are reset. The idea is that the `defaultValue`
represents the current, canonical value sent by the server.
Note: this change has no effect on form submissions that aren't
triggered by an action.
This PR moves `flushSync` out of the reconciler. there is still an
internal implementation that is used when these semantics are needed for
React methods such as `unmount` on roots.
This new isomorphic `flushSync` is only used in builds that no longer
support legacy mode.
Additionally all the internal uses of flushSync in the reconciler have
been replaced with more direct methods. There is a new
`updateContainerSync` method which updates a container but forces it to
the Sync lane and flushes passive effects if necessary. This combined
with flushSyncWork can be used to replace flushSync for all instances of
internal usage.
We still maintain the original flushSync implementation as
`flushSyncFromReconciler` because it will be used as the flushSync
implementation for FB builds. This is because it has special legacy mode
handling that the new isomorphic implementation does not need to
consider. It will be removed from production OSS builds by closure
though
Currently updatePriority is tracked in the reconciler. `flushSync` is
going to be implemented reconciler agnostic soon and we need to move the
tracking of this state to the renderer and out of reconciler. This
change implements new renderer bin dings for getCurrentUpdatePriority
and setCurrentUpdatePriority.
I was originally going to have the getter also do the event priority
defaulting using window.event so we eliminate getCur rentEventPriority
but this makes all the callsites where we store the true current
updatePriority on the stack harder to work with so for now they remain
separate.
I also moved runWithPriority to the renderer since it really belongs
whereever the state is being managed and it is only currently exposed in
the DOM renderer.
Additionally the current update priority is not stored on
ReactDOMSharedInternals. While not particularly meaningful in this
change it opens the door to implementing `flushSync` outside of the
reconciler
Stacked on #28627.
This makes error logging configurable using these
`createRoot`/`hydrateRoot` options:
```
onUncaughtError(error: mixed, errorInfo: {componentStack?: ?string}) => void
onCaughtError(error: mixed, errorInfo: {componentStack?: ?string, errorBoundary?: ?React.Component<any, any>}) => void
onRecoverableError(error: mixed, errorInfo: {digest?: ?string, componentStack?: ?string}) => void
```
We already have the `onRecoverableError` option since before.
Overriding these can be used to implement custom error dialogs (with
access to the `componentStack`).
It can also be used to silence caught errors when testing an error
boundary or if you prefer not getting logs for caught errors that you've
already handled in an error boundary.
I currently expose the error boundary instance but I think we should
probably remove that since it doesn't make sense for non-class error
boundaries and isn't very useful anyway. It's also unclear what it
should do when an error is rethrown from one boundary to another.
Since these are public APIs now we can implement the
ReactFiberErrorDialog forks using these options at the roots of the
builds. So I unforked those files and instead passed a custom option for
the native and www builds.
To do this I had to fork the ReactDOMLegacy file into ReactDOMRootFB
which is a duplication but that will go away as soon as the FB fork is
the only legacy root.
Based on
- https://github.com/facebook/react/pull/28497
- https://github.com/facebook/react/pull/28419
Reusing the disableLegacyMode flag, we set ReactTestRenderer to always
render with concurrent root where legacy APIs are no longer available.
If disableLegacyMode is false, we continue to allow the
unstable_isConcurrent option determine the root type.
Also checking a global `IS_REACT_NATIVE_TEST_ENVIRONMENT` so we can
maintain the existing behavior for RN until we remove legacy root
support there.
Based on
- https://github.com/facebook/react/pull/28419
## Summary
The shallow renderer was extracted from the repo years ago and published
by enzyme: https://github.com/enzymejs/react-shallow-renderer
We no longer need to reexport under the react-test-renderer namespace.
People can import `react-shallow-renderer` as needed
## How did you test this change?
- Observe shallow.js in react-test-renderer package from standard build
- Run build with changes on this branch
- Observe no more shallow.js export in build output
## Summary
Based on
- https://github.com/facebook/react/pull/27903
This PR
- Silence warning in React tests
- Turn on flag
We want to finish cleaning up internal RTR usage, but let's prioritize
the deprecation process. We do this by silencing the internal warning
for now.
## How did you test this change?
`yarn build`
`yarn test ReactHooksInspectionIntegration -b`
This bumps the canary versions to v19 to communicate that the next
release will be a major. Once this lands, we can start merging breaking
changes into `main`.
Reverting some of https://github.com/facebook/react/pull/27804 which
renamed this option to stable. This PR just replaces internal usage to
make upcoming PRs cleaner.
Keeping isConcurrent unstable for the next major release in order to
enable a broader deprecation of RTR and be consistent with concurrent
rendering everywhere for next major.
(https://github.com/facebook/react/pull/28498)
- Next major will use concurrent root
- The old behavior (legacy root by default, concurrent root with
unstable option) will be preserved for React Native until new
architecture is fully shipped.
- Flag and legacy root usage can be removed after RN dependency is
unblocked without an additional breaking change
We broke the ability to "break on uncaught exceptions" by adding a
try/catch higher up in the scheduling. We're giving up on fixing that so
we can remove the replay trick inside an event handler.
The issue with that approach is that we end up double logging a lot of
errors in DEV since they get reported to the page.
It's also a lot of complexity around this feature.
## Summary
Moving towards deprecation of ReactTestRenderer. Log a warning on each
render so we can remove the exports in a future major version.
We can enable this flag in web RTR without disrupting RN tests by
flipping the flag in
`packages/shared/forks/ReactFeatureFlags.test-renderer.js`
## How did you test this change?
`yarn test
packages/react-test-renderer/src/__tests__/ReactTestRenderer-test.js`
Depends on:
- #28317
- #28320
---
Changes the behavior of the JSX runtime to pass through `ref` as a
normal prop, rather than plucking it from the props object and storing
on the element.
This is a breaking change since it changes the type of the receiving
component. However, most code is unaffected since it's unlikely that a
component would have attempted to access a `ref` prop, since it was not
possible to get a reference to one.
`forwardRef` _will_ still pluck `ref` from the props object, though,
since it's extremely common for users to spread the props object onto
the inner component and pass `ref` as a differently named prop. This is
for maximum compatibility with existing code — the real impact of this
change is that `forwardRef` is no longer required.
Currently, refs are resolved during child reconciliation and stored on
the fiber. As a result of this change, we can move ref resolution to
happen only much later, and only for components that actually use them.
Then we can remove the `ref` field from the Fiber type. I have not yet
done that in this step, though.
Instead of createElement.
We should have done this when we initially released jsx-runtime but
better late than never. The general principle is that our tests should
be written using the most up-to-date idioms that we recommend for users,
except when explicitly testing an edge case or legacy behavior, like for
backwards compatibility.
Most of the diff is related to tweaking test output and isn't very
interesting.
I did have to workaround an issue related to component stacks. The
component stack logic depends on shared state that lives in the React
module. The problem is that most of our tests reset the React module
state and re-require a fresh instance of React, React DOM, etc. However,
the JSX runtime is not re-required because it's injected by the compiler
as a static import. This means its copy of the shared state is no longer
the same as the one used by React, causing any warning logged by the JSX
runtime to not include a component stack. (This same issue also breaks
string refs, but since we're removing those soon I'm not so concerned
about that.) The solution I went with for now is to mock the JSX runtime
with a proxy that re-requires the module on every function invocation. I
don't love this but it will have to do for now. What we should really do
is migrate our tests away from manually resetting the module state and
use import syntax instead.
Starting in version 19, users can import the `act` testing API from the
`react` package instead of using a renderer specific API, like
`react-dom/test-utils`.
## Summary
Concurrent rendering has been the default since React 18 release.
ReactTestRenderer requires passing `{unstable_isConcurrent: true}` to
match this behavior, which means by default tests written with RTR use a
different rendering method than the code they test.
Eventually, RTR should only use ConcurrentRoot. As a first step, let's
add a version of the concurrent option that isn't marked unstable. Next
we will follow up with removing the unstable option when it is safe to
merge.
## How did you test this change?
`yarn test
packages/react-test-renderer/src/__tests__/ReactTestRendererAsync-test.js`
## Overview
Does a few things:
- Renames `enableSyncDefaultUpdates` to
`forceConcurrentByDefaultForTesting`
- Changes the way it's used so it's dead-code eliminated separate from
`allowConcurrentByDefault`
- Deletes a bunch of the gated code
The gates that are deleted are unnecessary now. We were keeping them
when we originally thought we would come back to being concurrent by
default. But we've shifted and now sync-by default is the desired
behavior long term, so there's no need to keep all these forked tests
around.
I'll follow up to delete more of the forked behavior if possible.
Ideally we wouldn't need this flag even if we're still using
`allowConcurrentByDefault`.
Just a small upgrade to keep us current and remove unused suppressions
(probably fixed by some upgrade since).
- `*` is no longer allowed and has been an alias for `any` for a while
now.
This hook reads the status of its ancestor form component, if it exists.
```js
const {pending, data, action, method} = useFormStatus();
```
It can be used to implement a loading indicator, for example. You can
think of it as a shortcut for implementing a loading state with the
useTransition hook.
For now, it's only available in the experimental channel. We'll share
docs once its closer to being stable. There are additional APIs that
will ship alongside it.
Internally it's implemented using startTransition + a context object.
That's a good way to think about its behavior, but the actual
implementation details may change in the future.
Because form elements cannot be nested, the implementation in the
reconciler does not bother to keep track of multiple nested "transition
providers". So although it's implemented using generic Fiber config
methods, it does currently make some assumptions based on React DOM's
requirements.
Stacked on #26570
Previously we restricted Float methods to only being callable while
rendering. This allowed us to make associations between calls and their
position in the DOM tree, for instance hoisting preinitialized styles
into a ShadowRoot or an iframe Document.
When considering how we are going to support Flight support in Float
however it became clear that this restriction would lead to compromises
on the implementation because the Flight client does not execute within
the context of a client render. We want to be able to disaptch Float
directives coming from Flight as soon as possible and this requires
being able to call them outside of render.
this patch modifies Float so that its methods are callable anywhere. The
main consequence of this change is Float will always use the Document
the renderer script is running within as the HoistableRoot. This means
if you preinit as style inside a component render targeting a ShadowRoot
the style will load in the ownerDocument not the ShadowRoot. Practially
speaking it means that preinit is not useful inside ShadowRoots and
iframes.
This tradeoff was deemed acceptable because these methods are
optimistic, not critical. Additionally, the other methods, preconntect,
prefetchDNS, and preload, are not impacted because they already operated
at the level of the ownerDocument and really only interface with the
Network cache layer.
I added a couple additional fixes that were necessary for getting tests
to pass that are worth considering separately.
The first commit improves the diff for `waitForThrow` so it compares
strings if possible.
The second commit makes invokeGuardedCallback not use metaprogramming
pattern and swallows any novel errors produced from trying to run the
guarded callback. Swallowing may not be the best we can do but it at
least protects React against rapid failure when something causes the
dispatchEvent to throw.
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## Summary
Browsers restore state like forms and scroll position right after the
popstate event. To make sure the page work as expected on back or
forward button, we need to flush transitions scheduled in a popstate
synchronously, and only yields if it suspends.
This PR adds a new HostConfig method to check if `window.event ===
'popstate'`, and `scheduleMicrotask` if a transition is scheduled in a
`PopStateEvent`.
## How did you test this change?
yarn test
This removes the concept of `prepareUpdate()`, behind a flag.
React Native already does everything in the commit phase, but generates
a temporary update payload before applying it.
React Fabric does it both in the render phase. Now it just moves it to a
single host config.
For DOM I forked updateProperties into one that does diffing and
updating in one pass vs just applying a pre-diffed updatePayload.
There are a few downsides of this approach:
- If only "children" has changed, we end up scheduling an update to be
done in the commit phase. Since we traverse through it anyway, it's
probably not much extra.
- It does more work in the commit phase so for a large tree that is
mostly unchanged, it'll stall longer.
- It does some extra work for special cases since that work happens if
anything has changed. We no longer have a deep bailout.
- The special cases now have to each replicate the "clean up old props"
loop, leading to extra code.
The benefit is that this doesn't allocate temporary extra objects
(possibly multiple per element if the array has to resize). It's less
work overall. It also gives us an option to reuse this function for a
sync render optimization.
Another benefit is that if we do the loop in the commit phase I can do
further optimizations by reading all props that I need for special cases
in that loop instead of polymorphic reads from props. This is what I'd
like to do in future refactors that would be stacked on top of this
change.
part of https://github.com/facebook/react/pull/26571
merging separately to improve tracking of files renames in git
Rename HostConfig files to FiberConfig to clarify they are configs for
Fiber and not Fizz/Flight. This better conforms to the naming used in
Flight and now Fizz of `ReactFlightServerConfig` and `ReactFizzConfig`
This reverts commit b2ae9ddb3b.
While the feature flag is fully rolled out, these tests are also testing
behavior set with an unstable flag on root, which for now we want to
preserve.
Not sure if there's a better way then adding a dynamic feature flag to
the www build?
When rendering a suspensey resource that we haven't seen before, it may
have loaded in the background while we were rendering. We should yield
to the main thread to see if the load event fires in an immediate task.
For example, if the resource for a link element has already loaded, its
load event will fire in a task right after React yields to the main
thread. Because the continuation task is not scheduled until right
before React yields, the load event will ping React before it resumes.
If this happens, we can resume rendering without showing a fallback.
I don't think this matters much for images, because the `completed`
property tells us whether the image has loaded, and during a non-urgent
render, we never block the main thread for more than 5ms at a time (for
now — we might increase this in the future). It matters more for
stylesheets because the only way to check if it has loaded is by
listening for the load event.
This is essentially the same trick that `use` does for userspace
promises, but a bit simpler because we don't need to replay the host
component's begin phase; the work-in-progress fiber already completed,
so we can just continue onto the next sibling without any additional
work.
As part of this change, I split the `shouldSuspendCommit` host config
method into separate `maySuspendCommit` and `preloadInstance` methods.
Previously `shouldSuspendCommit` was used for both.
This raised a question of whether we should preload resources during a
synchronous render. My initial instinct was that we shouldn't, because
we're going to synchronously block the main thread until the resource is
inserted into the DOM, anyway. But I wonder if the browser is able to
initiate the preload even while the main thread is blocked. It's
probably a micro-optimization either way because most resources will be
loaded during transitions, not urgent renders.
This adds a new capability for renderers (React DOM, React Native):
prevent a tree from being displayed until it is ready, showing a
fallback if necessary, but without blocking the React components from
being evaluated in the meantime.
A concrete example is CSS loading: React DOM can block a commit from
being applied until the stylesheet has loaded. This allows us to load
the CSS asynchronously, while also preventing a flash of unstyled
content. Images and fonts are some of the other use cases.
You can think of this as "Suspense for the commit phase". Traditional
Suspense, i.e. with `use`, blocking during the render phase: React
cannot proceed with rendering until the data is available. But in the
case of things like stylesheets, you don't need the CSS in order to
evaluate the component. It just needs to be loaded before the tree is
committed. Because React buffers its side effects and mutations, it can
do work in parallel while the stylesheets load in the background.
Like regular Suspense, a "suspensey" stylesheet or image will trigger
the nearest Suspense fallback if it hasn't loaded yet. For now, though,
we only do this for non-urgent updates, like with startTransition. If
you render a suspensey resource during an urgent update, it will revert
to today's behavior. (We may or may not add a way to suspend the commit
during an urgent update in the future.)
In this PR, I have implemented this capability in the reconciler via new
methods added to the host config. I've used our internal React "no-op"
renderer to write tests that demonstrate the feature. I have not yet
implemented Suspensey CSS, images, etc in React DOM. @gnoff and I will
work on that in subsequent PRs.
`Scheduler.unstable_flushAll` in existing tests doesn't work with
microtask. This PR converts most of the remaining
`Scheduler.unstable_flushAll()` calls to using internal test utilities
to unblock refactoring `ensureRootIsScheduled` with scheduling a
microtask.
If something throws as a result of `flushSync`, and there's remaining
work left in the queue, React should keep working until all the work is
complete.
If multiple errors are thrown, React will combine them into an
AggregateError object and throw that. In environments where
AggregateError is not available, React will rethrow in an async task.
(All the evergreen runtimes support AggregateError.)
The scenario where this happens is relatively rare, because `flushSync`
will only throw if there's no error boundary to capture the error.
This fixes a handful of tests that were accidentally relying on React
synchronously queuing work in the Scheduler after a setState.
Usually this is because they use a lower level SchedulerMock method
instead of either `act` or one of the `waitFor` helpers. In some cases,
the solution is to switch to those APIs. In other cases, if we're
intentionally testing some lower level behavior, we might have to be a
bit more clever.
Co-authored-by: Tianyu Yao <skyyao@fb.com>
(This only affects our own internal repo; it's not a public API.)
I think most of us agree this is a less confusing name. It's possible
someone will confuse it with `console.log`. If that becomes a problem we
can warn in dev or something.
This converts some of our test suite to use the `waitFor` test pattern,
instead of the `expect(Scheduler).toFlushAndYield` pattern. Most of
these changes are automated with jscodeshift, with some slight manual
cleanup in certain cases.
See #26285 for full context.
## Hoistables
In the original implementation of Float, all hoisted elements were
treated like Resources. They had deduplication semantics and hydrated
based on a key. This made certain kinds of hoists very challenging such
as sequences of meta tags for `og:image:...` metadata. The reason is
each tag along is not dedupable based on only it's intrinsic properties.
two identical tags may need to be included and hoisted together with
preceding meta tags that describe a semantic object with a linear set of
html nodes.
It was clear that the concept of Browser Resources (stylesheets /
scripts / preloads) did not extend universally to all hositable tags
(title, meta, other links, etc...)
Additionally while Resources benefit from deduping they suffer an
inability to update because while we may have multiple rendered elements
that refer to a single Resource it isn't unambiguous which element owns
the props on the underlying resource. We could try merging props, but
that is still really hard to reason about for authors. Instead we
restrict Resource semantics to freezing the props at the time the
Resource is first constructed and warn if you attempt to render the same
Resource with different props via another rendered element or by
updating an existing element for that Resource.
This lack of updating restriction is however way more extreme than
necessary for instances that get hoisted but otherwise do not dedupe;
where there is a well defined DOM instance for each rendered element. We
should be able to update props on these instances.
Hoistable is a generalization of what Float tries to model for hoisting.
Instead of assuming every hoistable element is a Resource we now have
two distinct categories, hoistable elements and hoistable resources. As
one might guess the former has semantics that match regular Host
Components except the placement of the node is usually in the <head>.
The latter continues to behave how the original implementation of
HostResource behaved with the first iteration of Float
### Hoistable Element
On the server hoistable elements render just like regular tags except
the output is stored in special queues that can be emitted in the stream
earlier than they otherwise would be if rendered in place. This also
allow for instance the ability to render a hoistable before even
rendering the <html> tag because the queues for hoistable elements won't
flush until after we have flushed the preamble (`<DOCTYPE
html><html><head>`).
On the client, hoistable elements largely operate like HostComponents.
The most notable difference is in the hydration strategy. If we are
hydrating and encounter a hoistable element we will look for all tags in
the document that could potentially be a match and we check whether the
attributes match the props for this particular instance. We also do this
in the commit phase rather than the render phase. The reason hydration
can be done for HostComponents in render is the instance will be removed
from the document if hydration fails so mutating it in render is safe.
For hoistables the nodes are not in a hydration boundary (Root or
SuspenseBoundary at time of writing) and thus if hydration fails and we
may have an instance marked as bound to some Fiber when that Fiber never
commits. Moving the hydration matching to commit ensures we will always
succeed in pairing the hoisted DOM instance with a Fiber that has
committed.
### Hoistable Resource
On the server and client the semantics of Resources are largely the same
they just don't apply to title, meta, and most link tags anymore.
Resources hoist and dedupe via an `href` key and are ref counted. In a
future update we will add a garbage collector so we can clean up
Resources that no longer have any references
## `<style>` support
In earlier implementations there was no support for <style> tags. This
PR adds support for treating `<style href="..."
precedence="...">...</style>` as a Resource analagous to `<link
rel="stylesheet" href="..." precedence="..." />`
It may seem odd at first to require an href to get Resource semantics
for a style tag. The rationale is that these are for inlining of actual
external stylesheets as an optimization and for URI like scoping of
inline styles for css-in-js libraries. The href indicates that the key
space for `<style>` and `<link rel="stylesheet" />` Resources is shared.
and the precedence is there to allow for interleaving of both kinds of
Style resources. This is an advanced feature that we do not expect most
app developers to use directly but will be quite handy for various
styling libraries and for folks who want to inline as much as possible
once Fizz supports this feature.
## refactor notes
* HostResource Fiber type is renamed HostHoistable to reflect the
generalization of the concept
* The Resource object representation is modified to reduce hidden class
checks and to use less memory overall
* The thing that distinguishes a resource from an element is whether the
Fiber has a memoizedState. If it does, it will use resource semantics,
otherwise element semantics
* The time complexity of matching hositable elements for hydration
should be improved
## Summary
- yarn.lock diff +-6249, **small pr**
- use jest-environment-jsdom by default
- uncaught error from jsdom is an error object instead of strings
- abortSignal.reason is read-only in jsdom and node,
https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal/reason
## How did you test this change?
ci green
---------
Co-authored-by: Sebastian Silbermann <silbermann.sebastian@gmail.com>
The old version of prettier we were using didn't support the Flow syntax
to access properties in a type using `SomeType['prop']`. This updates
`prettier` and `rollup-plugin-prettier` to the latest versions.
I added the prettier config `arrowParens: "avoid"` to reduce the diff
size as the default has changed in Prettier 2.0. The largest amount of
changes comes from function expressions now having a space. This doesn't
have an option to preserve the old behavior, so we have to update this.
