react/packages/shared/ReactFeatureFlags.js
Dan Abramov 47b003a828
Resolve host configs at build time (#12792)
* Extract base Jest config

This makes it easier to change the source config without affecting the build test config.

* Statically import the host config

This changes react-reconciler to import HostConfig instead of getting it through a function argument.

Rather than start with packages like ReactDOM that want to inline it, I started with React Noop and ensured that *custom* renderers using react-reconciler package still work. To do this, I'm making HostConfig module in the reconciler look at a global variable by default (which, in case of the react-reconciler npm package, ends up being the host config argument in the top-level scope).

This is still very broken.

* Add scaffolding for importing an inlined renderer

* Fix the build

* ES exports for renderer methods

* ES modules for host configs

* Remove closures from the reconciler

* Check each renderer's config with Flow

* Fix uncovered Flow issue

We know nextHydratableInstance doesn't get mutated inside this function, but Flow doesn't so it thinks it may be null.
Help Flow.

* Prettier

* Get rid of enable*Reconciler flags

They are not as useful anymore because for almost all cases (except third party renderers) we *know* whether it supports mutation or persistence.

This refactoring means react-reconciler and react-reconciler/persistent third-party packages now ship the same thing.
Not ideal, but this seems worth how simpler the code becomes. We can later look into addressing it by having a single toggle instead.

* Prettier again

* Fix Flow config creation issue

* Fix imprecise Flow typing

* Revert accidental changes
2018-05-19 11:29:11 +01:00

46 lines
1.6 KiB
JavaScript

/**
* Copyright (c) 2013-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
*/
import invariant from 'fbjs/lib/invariant';
// Exports ReactDOM.createRoot
export const enableUserTimingAPI = __DEV__;
// Experimental error-boundary API that can recover from errors within a single
// render phase
export const enableGetDerivedStateFromCatch = false;
// Suspense
export const enableSuspense = false;
// Helps identify side effects in begin-phase lifecycle hooks and setState reducers:
export const debugRenderPhaseSideEffects = false;
// In some cases, StrictMode should also double-render lifecycles.
// This can be confusing for tests though,
// And it can be bad for performance in production.
// This feature flag can be used to control the behavior:
export const debugRenderPhaseSideEffectsForStrictMode = __DEV__;
// To preserve the "Pause on caught exceptions" behavior of the debugger, we
// replay the begin phase of a failed component inside invokeGuardedCallback.
export const replayFailedUnitOfWorkWithInvokeGuardedCallback = __DEV__;
// Warn about deprecated, async-unsafe lifecycles; relates to RFC #6:
export const warnAboutDeprecatedLifecycles = false;
// Gather advanced timing metrics for Profiler subtrees.
export const enableProfilerTimer = __DEV__;
// Fires getDerivedStateFromProps for state *or* props changes
export const fireGetDerivedStateFromPropsOnStateUpdates = true;
// Only used in www builds.
export function addUserTimingListener() {
invariant(false, 'Not implemented.');
}