The mock Scheduler that we use in our tests has its own fake timer
implementation. The `unstable_advanceTime` method advances the timeline.
Currently, a call to `unstable_advanceTime` will also flush any pending
expired work. But that's not how it works in the browser: when a timer
fires, the corresponding task is added to the Scheduler queue. However,
we will still wait until the next message event before flushing it.
This commit changes `unstable_advanceTime` to more closely resemble the
browser behavior, by removing the automatic flushing of expired work.
```js
// Before this commit
Scheduler.unstable_advanceTime(ms);
// Equivalent behavior after this commit
Scheduler.unstable_advanceTime(ms);
Scheduler.unstable_flushExpired();
```
The general principle is to prefer separate APIs for scheduling tasks
and flushing them.
This change does not affect any public APIs. `unstable_advanceTime` is
only used by our own test suite. It is not used by `act`.
However, we may need to update tests in www, like Relay's.
This PR introduces adds `react/testing` and `react-dom/testing`.
- changes infra to generate these builds
- exports act on ReactDOM in these testing builds
- uses the new test builds in fixtures/dom
In the next PR -
- I'll use the new builds for all our own tests
- I'll replace usages of TestUtils.act with ReactDOM.act.
* Simplify Continuous Hydration Targets
Let's use a constant priority for this. This helps us avoid restarting
a render when switching targets and simplifies the model.
The downside is that now we're not down-prioritizing the previous hover
target. However, we think that's ok because it'll only do one level too
much and then stop.
* Add test meant to show why it's tricky to merge both hydration levels
Having both levels co-exist works. However, if we deprioritize hydration
using a single level, we might deprioritize the wrong thing.
This adds a test that catches it if we ever try a naive deprioritization
in the future.
It also tests that we don't down-prioritize if we're changing the hover
in the middle of doing continuous priority work.
* Add test of Event Replaying using Flare
* Fix Event Replaying in Flare by Eagerly Adding Active Listeners
This effectively reverts part of https://github.com/facebook/react/pull/17513
The changes to the test code relate to changes in JSDOM that come with Jest 25:
* Several JSDOM workarounds are no longer needed.
* Several tests made assertions to match incorrect JSDOM behavior (e.g. setAttribute calls) that JSDOM has now patched to match browsers.
* https://codesandbox.io/s/resets-value-of-datetime-input-to-fix-bugs-in-ios-safari-1ppwh
* JSDOM no longer triggers default actions when dispatching click events.
* https://codesandbox.io/s/beautiful-cdn-ugn8f
* JSDOM fixed (jsdom/jsdom#2700) a bug so that calling focus() on an already focused element does not dispatch a FocusEvent.
* JSDOM now supports passive events.
* JSDOM has improved support for custom CSS properties.
* But requires jsdom/cssstyle#112 to land to support webkit prefixed properties.
When owner and self are different for string refs, we can't easily convert them to callback refs. This PR adds a warning for string refs when owner and self are different to tell users to manually update these refs.
* Update Flow to 0.84
* Fix violations
* Use inexact object syntax in files from fbsource
* Fix warning extraction to use a modern parser
* Codemod inexact objects to new syntax
* Tighten types that can be exact
* Revert unintentional formatting changes from codemod
* Remove toString of dangerouslySetInnerHTML
As far as I can tell, the toString call was added here:
https://github.com/facebook/react/commit/caae627cd557812d28d11237b34bff6c661ea8bc#diff-5574f655d491348f422bca600ff6711dR887
It was never really needed. Subsequently when we added Trusted Types,
this needed to be changed to a special call but we really should just
always let it pass through.
* Remove special casing of toString values when enableTrustedTypesIntegration
As far as I can tell, we only toString in user space because of IE8/9.
We don't really support IE8/9 anymore and by the time this flag is on,
we should be able to deprecate it.
Unless this is also an issue in IE11. I haven't tested yet.
* Replace all warning/lowPriWarning with console calls
* Replace console.warn/error with a custom wrapper at build time
* Fail the build for console.error/warn() where we can't read the stack
* prep for codemod
* prep warnings
* rename lint rules
* codemod for ifs
* shim www functions
* Handle more cases in the transform
* Thanks De Morgan
* Run the codemod
* Delete the transform
* Fix up confusing conditions manually
* Fix up www shims to match expected API
* Also check for low-pri warning in the lint rule
* Replace Babel plugin with an ESLint plugin
* Fix ESLint rule violations
* Move shared conditions higher
* Test formatting nits
* Tweak ESLint rule
* Bugfix: inside else branch, 'if' tests are not satisfactory
* Use a stricter check for exactly if (__DEV__)
This makes it easier to see what's going on and matches dominant style in the codebase.
* Fix remaining files after stricter check
* Move Flight DOM to Webpack Specific Packagee
We'll have Webpack specific coupling so we need to ensure that it can be
versioned separately from various Webpack versions. We'll also have builds
for other bundlers in the future.
* Move to peerDep
* Move DOM Flight Tests
* Merge ReactFlightIntegration into ReactFlightDOM
This was an integration test. We can add to it.
* Fix fixture paths
* Regression test: Effects dropped across roots
See #17066
* [Bugfix] Passive effects loop
The bug
-------
In a multi-root app, certain passive effects (`useEffect`) are never
fired. See #17066.
The underlying problem
----------------------
The implicit contract of `flushPassiveEffects` is that, right after
calling it, there should be no pending passive effects. In the normal
case, in concurrent mode, this is true. But the current implementation
fails to account for the case where a passive effect schedules
synchronous work, which in turn schedules additional passive effects.
This led to `rootWithPendingPassiveEffects` being overwritten in the
commit phase, because an assignment that assumed it was replacing null
was actually replacing a reference to another root, which has the
consequence of dropping passive effects on that root.
The fix
-------
The fix I've chosen here is, at the beginning of the commit phase, keep
flushing passive effects in a loop until there are no more.
This doesn't not change the "public" implementation of
`flushPassiveEffects`, though it arguably should work this way, too. I
say "public" because it's only used by implementation layers on top of
React which we control: mainly, the legacy version of `act` that does
not use the mock Scheduler build. So there's probably still a bug
in that `act` implementation.
I will address `act` in a follow-up. The ideal solution is to replace
the legacy `act` with one implemented directly in the renderer, using a
special testing-only build of React DOM. Since that requires a breaking
change, we'll need an interim solution. We could make the "public" `act`
recursively flush effects in a loop, as I've done for the commit phase.
However, I think a better solution is to stop automatically flushing the
synchronous update queue at the end of `flushPassiveEffects`, and
instead require the caller to explicitly call `flushSyncUpdateQueue` (or
the equivalent) if needed. This follows the same pattern we use
internally in the work loop, which is designed to avoid factoring
hazards like the one that resulted in this bug.
* Unify fields used for createRoot warning and event system
* Warn when doing createRoot twice on the same node
* Stricter check for modern roots
* Unmark asynchronously
* Fix Flow
* [Flight] Basic Integration Test
* Just act()
* Lint
* Remove unnecessary acts
* Use Concurrent Mode
* it.experimental
* Fix prod test by advancing time
* Don't observe initial state
* Return whether to keep flowing in Host config
* Emit basic chunk based streaming in the Flight server
When something suspends a new chunk is created.
* Add reentrancy check
The WHATWG API is designed to be pulled recursively.
We should refactor to favor that approach.
* Basic streaming Suspense support on the client
* Add basic suspense in example
* Add comment describing the protocol that the server generates
* Rename ReactFlightStreamer -> ReactFlightServer
* Unify Browser/Node stream tests into one file and use the client reader
* Defer to the actual ReactDOM for HTML rendering for now
This will need to use a variant of Fizz to do inline SSR in Flight.
However, I don't want to build the whole impl right now but also don't
want to exclude the use case yet. So I outsource it to the existing
renderer. Ofc, this doesn't work with Suspense atm.