react/packages/shared/forks/ReactFeatureFlags.testing.js

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/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
*/
import typeof * as FeatureFlagsType from 'shared/ReactFeatureFlags';
import typeof * as ExportsType from './ReactFeatureFlags.testing';
export const debugRenderPhaseSideEffectsForStrictMode = false;
export const enableDebugTracing = false;
export const enableSchedulingProfiler = false;
export const warnAboutDeprecatedLifecycles = true;
export const replayFailedUnitOfWorkWithInvokeGuardedCallback = false;
export const enableProfilerTimer = __PROFILE__;
export const enableProfilerCommitHooks = false;
Add "nested-update" phase to Profiler API (#20163) Background: State updates that are scheduled in a layout effect (useLayoutEffect or componentDidMount / componentDidUpdate) get processed synchronously by React before it yields to the browser to paint. This is done so that components can adjust their layout (e.g. position and size a tooltip) without any visible shifting being seen by users. This type of update is often called a "nested update" or a "cascading update". Because they delay paint, nested updates are considered expensive and should be avoided when possible. For example, effects that do not impact layout (e.g. adding event handlers, logging impressions) can be safely deferred to the passive effect phase by using useEffect instead. This PR updates the Profiler API to explicitly flag nested updates so they can be monitored for and avoided when possible. Implementation: I considered a few approaches for this. Add a new callback (e.g. onNestedUpdateScheduled) to the Profiler that gets called when a nested updates gets scheduled. Add an additional boolean parameter to the end of existing callbacks (e.g. wasNestedUpdate). Update the phase param to add an additional variant: "mount", "update", or "nested-update" (new). I think the third option makes for the best API so that's what I've implemented in this PR. Because the Profiler API is stable, this change will need to remain behind a feature flag until v18. I've turned the feature flag on for Facebook builds though after confirming that Web Speed does not currently make use of the phase parameter. Quirks: One quirk about the implementation I've chosen is that errors thrown during the layout phase are also reported as nested updates. I believe this is appropriate since these errors get processed synchronously and block paint. Errors thrown during render or from within passive effects are not affected by this change.
2020-11-10 22:40:30 +08:00
export const enableProfilerNestedUpdatePhase = false;
export const enableProfilerNestedUpdateScheduledHook = false;
export const enableSchedulerTracing = __PROFILE__;
export const enableSuspenseServerRenderer = false;
export const enableSelectiveHydration = false;
export const enableLazyElements = false;
export const enableCache = false;
export const disableJavaScriptURLs = false;
export const disableInputAttributeSyncing = false;
export const enableSchedulerDebugging = false;
export const enableFundamentalAPI = false;
export const enableScopeAPI = false;
export const enableCreateEventHandleAPI = false;
export const warnAboutUnmockedScheduler = false;
export const enableSuspenseCallback = false;
export const warnAboutDefaultPropsOnFunctionComponents = false;
export const warnAboutStringRefs = false;
export const disableLegacyContext = false;
export const disableSchedulerTimeoutBasedOnReactExpirationTime = false;
export const enableTrustedTypesIntegration = false;
export const disableTextareaChildren = false;
export const disableModulePatternComponents = false;
export const warnUnstableRenderSubtreeIntoContainer = false;
export const warnAboutSpreadingKeyToJSX = false;
export const enableComponentStackLocations = true;
export const enableLegacyFBSupport = false;
export const enableFilterEmptyStringAttributesDOM = false;
export const disableNativeComponentFrames = false;
export const skipUnmountedBoundaries = false;
export const enableNewReconciler = false;
export const deferRenderPhaseUpdateToNextBatch = true;
Decouple update priority tracking from Scheduler package (#19121) * Initial currentLanePriority implementation * Minor updates from review * Fix typos and enable flag * Fix feature flags and lint * Fix simple event tests by switching to withSuspenseConfig * Don't lower the priority of setPending in startTransition below InputContinuous * Move currentUpdateLanePriority in commit root into the first effect block * Refactor requestUpdateLane to log for priority mismatches Also verifies that the update lane priority matches the scheduler lane priority before using it * Fix four tests by adding ReactDOM.unstable_runWithPriority * Fix partial hydration when using update lane priority * Fix partial hydration when using update lane priority * Rename feature flag and only log for now * Move unstable_runWithPriority to ReactFiberReconciler * Add unstable_runWithPriority to ReactNoopPersistent too * Bug fixes and performance improvements * Initial currentLanePriority implementation * Minor updates from review * Fix typos and enable flag * Remove higherLanePriority from ReactDOMEventReplaying.js * Change warning implementation and startTransition update lane priority * Inject reconciler functions to avoid importing src/ * Fix feature flags and lint * Fix simple event tests by switching to withSuspenseConfig * Don't lower the priority of setPending in startTransition below InputContinuous * Move currentUpdateLanePriority in commit root into the first effect block * Refactor requestUpdateLane to log for priority mismatches Also verifies that the update lane priority matches the scheduler lane priority before using it * Fix four tests by adding ReactDOM.unstable_runWithPriority * Fix partial hydration when using update lane priority * Fix partial hydration when using update lane priority * Rename feature flag and only log for now * Move unstable_runWithPriority to ReactFiberReconciler * Bug fixes and performance improvements * Remove higherLanePriority from ReactDOMEventReplaying.js * Change warning implementation and startTransition update lane priority * Inject reconciler functions to avoid importing src/ * Fixes from bad rebase
2020-07-07 06:53:42 +08:00
export const decoupleUpdatePriorityFromScheduler = false;
export const enableDiscreteEventFlushingChange = false;
export const enableDoubleInvokingEffects = false;
export const enableUseRefAccessWarning = false;
export const enableRecursiveCommitTraversal = false;
export const disableSchedulerTimeoutInWorkLoop = false;
// Flow magic to verify the exports of this file match the original version.
// eslint-disable-next-line no-unused-vars
type Check<_X, Y: _X, X: Y = _X> = null;
// eslint-disable-next-line no-unused-expressions
(null: Check<ExportsType, FeatureFlagsType>);