ReactDOMSelection-test.internal.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.
 *
 * @emails react-core
 */

'use strict';

let React;
let ReactDOMClient;
let ReactDOMSelection;
let act;

let getModernOffsetsFromPoints;

describe('ReactDOMSelection', () => {
  beforeEach(() => {
    React = require('react');
    ReactDOMClient = require('react-dom/client');
    ReactDOMSelection = require('react-dom-bindings/src/client/ReactDOMSelection');
    act = require('internal-test-utils').act;

    ({getModernOffsetsFromPoints} = ReactDOMSelection);
  });

  // Simple implementation to compare correctness. React's old implementation of
  // this logic used DOM Range objects and is available for manual testing at
  // https://gist.github.com/sophiebits/2e6d571f4f10f33b62ea138a6e9c265c.
  function simpleModernOffsetsFromPoints(
    outerNode,
    anchorNode,
    anchorOffset,
    focusNode,
    focusOffset,
  ) {
    let start;
    let end;
    let length = 0;

    function traverse(node) {
      if (node.nodeType === Node.TEXT_NODE) {
        if (node === anchorNode) {
          start = length + anchorOffset;
        }
        if (node === focusNode) {
          end = length + focusOffset;
        }
        length += node.nodeValue.length;
        return;
      }

      for (let i = 0; true; i++) {
        if (node === anchorNode && i === anchorOffset) {
          start = length;
        }
        if (node === focusNode && i === focusOffset) {
          end = length;
// ... (148 more lines)