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https://github.com/zebrajr/react.git
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56636353d8
Provides partial support for React.lazy() components from the existing PartialRenderer server-side renderer. Lazy components which are already resolved (or rejected), perhaps with something like `react-ssr-prepass`, can be continued into synchronously. If they have not yet been initialized, they'll be initialized before checking, opening the possibility to exploit this capability with a babel transform. If they're pending (which will typically be the case for a just initialized async ctor) then the existing invariant continues to be thrown.
77 lines
2.0 KiB
JavaScript
77 lines
2.0 KiB
JavaScript
/**
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*
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* @flow
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*/
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import warning from 'shared/warning';
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export type Thenable<T, R> = {
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then(resolve: (T) => mixed, reject: (mixed) => mixed): R,
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};
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export type LazyComponent<T> = {
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$$typeof: Symbol | number,
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_ctor: () => Thenable<{default: T}, mixed>,
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_status: 0 | 1 | 2,
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_result: any,
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};
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type ResolvedLazyComponent<T> = {
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$$typeof: Symbol | number,
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_ctor: () => Thenable<{default: T}, mixed>,
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_status: 1,
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_result: any,
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};
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export const Uninitialized = -1;
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export const Pending = 0;
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export const Resolved = 1;
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export const Rejected = 2;
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export function refineResolvedLazyComponent<T>(
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lazyComponent: LazyComponent<T>,
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): ResolvedLazyComponent<T> | null {
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return lazyComponent._status === Resolved ? lazyComponent._result : null;
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}
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export function initializeLazyComponentType(
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lazyComponent: LazyComponent<any>,
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): void {
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if (lazyComponent._status === Uninitialized) {
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lazyComponent._status = Pending;
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const ctor = lazyComponent._ctor;
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const thenable = ctor();
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lazyComponent._result = thenable;
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thenable.then(
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moduleObject => {
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if (lazyComponent._status === Pending) {
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const defaultExport = moduleObject.default;
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if (__DEV__) {
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if (defaultExport === undefined) {
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warning(
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false,
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'lazy: Expected the result of a dynamic import() call. ' +
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'Instead received: %s\n\nYour code should look like: \n ' +
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"const MyComponent = lazy(() => import('./MyComponent'))",
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moduleObject,
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);
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}
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}
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lazyComponent._status = Resolved;
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lazyComponent._result = defaultExport;
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}
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},
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error => {
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if (lazyComponent._status === Pending) {
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lazyComponent._status = Rejected;
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lazyComponent._result = error;
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}
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},
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);
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}
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}
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