Stacked on top of #28498 for test fixes.
### Don't Rethrow
When we started React it was 1:1 setState calls a series of renders and
if they error, it errors where the setState was called. Simple. However,
then batching came and the error actually got thrown somewhere else.
With concurrent mode, it's not even possible to get setState itself to
throw anymore.
In fact, all APIs that can rethrow out of React are executed either at
the root of the scheduler or inside a DOM event handler.
If you throw inside a React.startTransition callback that's sync, then
that will bubble out of the startTransition but if you throw inside an
async callback or a useTransition we now need to handle it at the hook
site. So in 19 we need to make all React.startTransition swallow the
error (and report them to reportError).
The only one remaining that can throw is flushSync but it doesn't really
make sense for it to throw at the callsite neither because batching.
Just because something rendered in this flush doesn't mean it was
rendered due to what was just scheduled and doesn't mean that it should
abort any of the remaining code afterwards. setState is fire and forget.
It's send an instruction elsewhere, it's not part of the current
imperative code.
Error boundaries never rethrow. Since you should really always have
error boundaries, most of the time, it wouldn't rethrow anyway.
Rethrowing also actually currently drops errors on the floor since we
can only rethrow the first error, so to avoid that we'd need to call
reportError anyway. This happens in RN events.
The other issue with rethrowing is that it logs an extra console.error.
Since we're not sure that user code will actually log it anywhere we
still log it too just like we do with errors inside error boundaries
which leads all of these to log twice.
The goal of this PR is to never rethrow out of React instead, errors
outside of error boundaries get logged to reportError. Event system
errors too.
### Breaking Changes
The main thing this affects is testing where you want to inspect the
errors thrown. To make it easier to port, if you're inside `act` we
track the error into act in an aggregate error and then rethrow it at
the root of `act`. Unlike before though, if you flush synchronously
inside of act it'll still continue until the end of act before
rethrowing.
I expect most user code breakages would be to migrate from `flushSync`
to `act` if you assert on throwing.
However, in the React repo we also have `internalAct` and the
`waitForThrow` helpers. Since these have to use public production
implementations we track these using the global onerror or process
uncaughtException. Unlike regular act, includes both event handler
errors and onRecoverableError by default too. Not just render/commit
errors. So I had to account for that in our tests.
We restore logging an extra log for uncaught errors after the main log
with the component stack in it. We use `console.warn`. This is not yet
ignorable if you preventDefault to the main error event. To avoid
confusion if you don't end up logging the error to console I just added
`An error occurred`.
### Polyfill
All browsers we support really supports `reportError` but not all test
and server environments do, so I implemented a polyfill for browser and
node in `shared/reportGlobalError`. I don't love that this is included
in all builds and gets duplicated into isomorphic even though it's not
actually needed in production. Maybe in the future we can require a
polyfill for this.
### Follow Ups
In a follow up, I'll make caught vs uncaught error handling be
configurable too.
---------
Co-authored-by: Ricky Hanlon <rickhanlonii@gmail.com>
Stacked on #28458.
This doesn't actually really change the messages yet, it's just a
refactor.
Hydration warnings can be presented either as HTML or React JSX format.
If presented as HTML it makes more sense to make that a DOM specific
concept, however, I think it's actually better to present it in terms of
React JSX.
Most of the time the errors aren't going to be something messing with
them at the HTML/HTTP layer. It's because the JS code does something
different. Most of the time you're working in just React. People don't
necessarily even know what the HTML form of it looks like. So this takes
the approach that the warnings are presented in React JSX in their rich
object form.
Therefore, I'm moving the approach to yield diff data to the reconciler
but it's the reconciler that's actually printing all the warnings.
## Overview
The error messages that say:
> ReactDOM.hydrate is no longer supported in React 18
Don't make sense in the React 19 release. Instead, they should say:
> ReactDOM.hydrate was removed in React 19.
For legacy mode, they should say:
> ReactDOM.hydrate has not been supported since React 18.
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.
## Overview
Adds support for `ReactDOMClient` for `ServerIntegration*` tests.
Also converts tests that pass without any other changes. Will follow up
with other PRs for more complex cases.
## 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>
Upgrades the deprecation warning to a runtime error.
I did it this way instead of removing the export so the type is the same
in both builds. It will get dead code eliminated regardless.
* Use existing test warning filter for server tests
We have a warning filter for our internal tests to ignore warnings
that are too noisy or that we haven't removed from our test suite yet:
shouldIgnoreConsoleError.
Many of our server rendering tests don't use this filter, though,
because it has its own special of asserting warnings.
So I added the warning filter to the server tests, too.
* Deprecate ReactDOM.render and ReactDOM.hydrate
These are no longer supported in React 18. They are replaced by the
`createRoot` API.
The warning includes a link to documentation of the new API. Currently
it redirects to the corresponding working group post. Here's the PR to
set up the redirect: https://github.com/reactjs/reactjs.org/pull/3730
Many of our tests still use ReactDOM.render. We will need to gradually
migrate them over to createRoot.
In the meantime, I added the warnings to our internal warning filter.
We have behaviour divergence for act() between prod and dev (specifically, act() + concurrent mode does not flush fallbacks in prod. This doesn't affect anyone in OSS yet)
We also don't have a good story for writing tests in prod (and what from what I gather, nobody really writes tests in prod mode).
We could have wiped out act() in prod builds, except that _we_ ourselves use act() for our tests when we run them in prod mode.
This PR is a compromise to all of this. We will log a warning if you try to use act() in prod mode, and we silence it in our test suites.
