ReactHooks.js

/**
 * Copyright (c) Meta Platforms, Inc. and 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 type {Dispatcher} from 'react-reconciler/src/ReactInternalTypes';
import type {
  ReactContext,
  StartTransitionOptions,
  Usable,
} from 'shared/ReactTypes';

import ReactCurrentDispatcher from './ReactCurrentDispatcher';
import ReactCurrentCache from './ReactCurrentCache';

type BasicStateAction<S> = (S => S) | S;
type Dispatch<A> = A => void;

function resolveDispatcher() {
  const dispatcher = ReactCurrentDispatcher.current;
  if (__DEV__) {
    if (dispatcher === null) {
      console.error(
        'Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for' +
          ' one of the following reasons:\n' +
          '1. You might have mismatching versions of React and the renderer (such as React DOM)\n' +
          '2. You might be breaking the Rules of Hooks\n' +
          '3. You might have more than one copy of React in the same app\n' +
          'See https://reactjs.org/link/invalid-hook-call for tips about how to debug and fix this problem.',
      );
    }
  }
  // Will result in a null access error if accessed outside render phase. We
  // intentionally don't throw our own error because this is in a hot path.
  // Also helps ensure this is inlined.
  return ((dispatcher: any): Dispatcher);
}

export function getCacheSignal(): AbortSignal {
  const dispatcher = ReactCurrentCache.current;
  if (!dispatcher) {
    // If we have no cache to associate with this call, then we don't know
    // its lifetime. We abort early since that's safer than letting it live
    // for ever. Unlike just caching which can be a functional noop outside
    // of React, these should generally always be associated with some React
    // render but we're not limiting quite as much as making it a Hook.
    // It's safer than erroring early at runtime.
    const controller = new AbortController();
    const reason = new Error(
      'This CacheSignal was requested outside React which means that it is ' +
        'immediately aborted.',
    );
    controller.abort(reason);
    return controller.signal;
  }
  return dispatcher.getCacheSignal();
}

export function getCacheForType<T>(resourceType: () => T): T {
  const dispatcher = ReactCurrentCache.current;
  if (!dispatcher) {
    // If there is no dispatcher, then we treat this as not being cached.
    return resourceType();
  }
  return dispatcher.getCacheForType(resourceType);
}

export function useContext<T>(Context: ReactContext<T>): T {
  const dispatcher = resolveDispatcher();
  if (__DEV__) {
    // TODO: add a more generic warning for invalid values.
    if ((Context: any)._context !== undefined) {
      const realContext = (Context: any)._context;
      // Don't deduplicate because this legitimately causes bugs
      // and nobody should be using this in existing code.
      if (realContext.Consumer === Context) {
        console.error(
          'Calling useContext(Context.Consumer) is not supported, may cause bugs, and will be ' +
            'removed in a future major release. Did you mean to call useContext(Context) instead?',
        );
      } else if (realContext.Provider === Context) {
        console.error(
          'Calling useContext(Context.Provider) is not supported. ' +
            'Did you mean to call useContext(Context) instead?',
        );
      }
    }
  }
  return dispatcher.useContext(Context);
}

export function useState<S>(
  initialState: (() => S) | S,
): [S, Dispatch<BasicStateAction<S>>] {
  const dispatcher = resolveDispatcher();
  return dispatcher.useState(initialState);
}

export function useReducer<S, I, A>(
  reducer: (S, A) => S,
  initialArg: I,
  init?: I => S,
): [S, Dispatch<A>] {
  const dispatcher = resolveDispatcher();
  return dispatcher.useReducer(reducer, initialArg, init);
}

export function useRef<T>(initialValue: T): {current: T} {
  const dispatcher = resolveDispatcher();
  return dispatcher.useRef(initialValue);
}

export function useEffect(
  create: () => (() => void) | void,
  deps: Array<mixed> | void | null,
): void {
  const dispatcher = resolveDispatcher();
  return dispatcher.useEffect(create, deps);
}

export function useInsertionEffect(
  create: () => (() => void) | void,
  deps: Array<mixed> | void | null,
): void {
  const dispatcher = resolveDispatcher();
  return dispatcher.useInsertionEffect(create, deps);
}

export function useLayoutEffect(
  create: () => (() => void) | void,
  deps: Array<mixed> | void | null,
): void {
  const dispatcher = resolveDispatcher();
  return dispatcher.useLayoutEffect(create, deps);
}

export function useCallback<T>(
  callback: T,
  deps: Array<mixed> | void | null,
): T {
  const dispatcher = resolveDispatcher();
  return dispatcher.useCallback(callback, deps);
}

export function useMemo<T>(
  create: () => T,
  deps: Array<mixed> | void | null,
): T {
  const dispatcher = resolveDispatcher();
  return dispatcher.useMemo(create, deps);
}

export function useImperativeHandle<T>(
  ref: {current: T | null} | ((inst: T | null) => mixed) | null | void,
  create: () => T,
  deps: Array<mixed> | void | null,
): void {
  const dispatcher = resolveDispatcher();
  return dispatcher.useImperativeHandle(ref, create, deps);
}

export function useDebugValue<T>(
  value: T,
  formatterFn: ?(value: T) => mixed,
): void {
  if (__DEV__) {
    const dispatcher = resolveDispatcher();
    return dispatcher.useDebugValue(value, formatterFn);
  }
}

export function useTransition(): [
  boolean,
  (callback: () => void, options?: StartTransitionOptions) => void,
] {
  const dispatcher = resolveDispatcher();
  return dispatcher.useTransition();
}

export function useDeferredValue<T>(value: T, initialValue?: T): T {
  const dispatcher = resolveDispatcher();
  return dispatcher.useDeferredValue(value, initialValue);
}

export function useId(): string {
  const dispatcher = resolveDispatcher();
  return dispatcher.useId();
}

export function useSyncExternalStore<T>(
  subscribe: (() => void) => () => void,
  getSnapshot: () => T,
  getServerSnapshot?: () => T,
): T {
  const dispatcher = resolveDispatcher();
  return dispatcher.useSyncExternalStore(
    subscribe,
    getSnapshot,
    getServerSnapshot,
  );
}

export function useCacheRefresh(): <T>(?() => T, ?T) => void {
  const dispatcher = resolveDispatcher();
  // $FlowFixMe[not-a-function] This is unstable, thus optional
  return dispatcher.useCacheRefresh();
}

export function use<T>(usable: Usable<T>): T {
  const dispatcher = resolveDispatcher();
  return dispatcher.use(usable);
}

export function useMemoCache(size: number): Array<any> {
  const dispatcher = resolveDispatcher();
  // $FlowFixMe[not-a-function] This is unstable, thus optional
  return dispatcher.useMemoCache(size);
}

export function useEffectEvent<Args, F: (...Array<Args>) => mixed>(
  callback: F,
): F {
  const dispatcher = resolveDispatcher();
  // $FlowFixMe[not-a-function] This is unstable, thus optional
  return dispatcher.useEffectEvent(callback);
}

export function useOptimistic<S, A>(
  passthrough: S,
  reducer: ?(S, A) => S,
): [S, (A) => void] {
  const dispatcher = resolveDispatcher();
  // $FlowFixMe[not-a-function] This is unstable, thus optional
  return dispatcher.useOptimistic(passthrough, reducer);
}