ReactFizzThenable.js — react Source File

Source Code

/**
 * 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
 */

// Corresponds to ReactFiberThenable and ReactFlightThenable modules. Generally,
// changes to one module should be reflected in the others.

import type {
  Thenable,
  PendingThenable,
  FulfilledThenable,
  RejectedThenable,
} from 'shared/ReactTypes';
import type {ComponentStackNode} from './ReactFizzComponentStack';

import noop from 'shared/noop';
import {currentTaskInDEV} from './ReactFizzCurrentTask';

export opaque type ThenableState = Array<Thenable<any>>;

// An error that is thrown (e.g. by `use`) to trigger Suspense. If we
// detect this is caught by userspace, we'll log a warning in development.
export const SuspenseException: mixed = new Error(
  "Suspense Exception: This is not a real error! It's an implementation " +
    'detail of `use` to interrupt the current render. You must either ' +
    'rethrow it immediately, or move the `use` call outside of the ' +
    '`try/catch` block. Capturing without rethrowing will lead to ' +
    'unexpected behavior.\n\n' +
    'To handle async errors, wrap your component in an error boundary, or ' +
    "call the promise's `.catch` method and pass the result to `use`.",
);

export function createThenableState(): ThenableState {
  // The ThenableState is created the first time a component suspends. If it
  // suspends again, we'll reuse the same state.
  return [];
}

export function trackUsedThenable<T>(
  thenableState: ThenableState,
  thenable: Thenable<T>,
  index: number,
): T {
  const previous = thenableState[index];
  if (previous === undefined) {
    thenableState.push(thenable);
  } else {
    if (previous !== thenable) {
      // Reuse the previous thenable, and drop the new one. We can assume
      // they represent the same value, because components are idempotent.

      // Avoid an unhandled rejection errors for the Promises that we'll
      // intentionally ignore.
      thenable.then(noop, noop);
      thenable = previous;
// ... (235 more lines)