draft-js/lib/DraftRemovableWord.js.flow

A React framework for building text editors.

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @format
 * @flow strict-local
 * @emails oncall+draft_js
 */
'use strict';

const TokenizeUtil = require("fbjs/lib/TokenizeUtil");

const punctuation = TokenizeUtil.getPunctuation(); // The apostrophe and curly single quotes behave in a curious way: when
// surrounded on both sides by word characters, they behave as word chars; when
// either neighbor is punctuation or an end of the string, they behave as
// punctuation.

const CHAMELEON_CHARS = "['\u2018\u2019]"; // Remove the underscore, which should count as part of the removable word. The
// "chameleon chars" also count as punctuation in this regex.

const WHITESPACE_AND_PUNCTUATION = '\\s|(?![_])' + punctuation;
const DELETE_STRING = '^' + '(?:' + WHITESPACE_AND_PUNCTUATION + ')*' + '(?:' + CHAMELEON_CHARS + '|(?!' + WHITESPACE_AND_PUNCTUATION + ').)*' + '(?:(?!' + WHITESPACE_AND_PUNCTUATION + ').)';
const DELETE_REGEX = new RegExp(DELETE_STRING);
const BACKSPACE_STRING = '(?:(?!' + WHITESPACE_AND_PUNCTUATION + ').)' + '(?:' + CHAMELEON_CHARS + '|(?!' + WHITESPACE_AND_PUNCTUATION + ').)*' + '(?:' + WHITESPACE_AND_PUNCTUATION + ')*' + '$';
const BACKSPACE_REGEX = new RegExp(BACKSPACE_STRING);

function getRemovableWord(text: string, isBackward: boolean): string {
  const matches = isBackward ? BACKSPACE_REGEX.exec(text) : DELETE_REGEX.exec(text);
  return matches ? matches[0] : text;
}

const DraftRemovableWord = {
  getBackward: function (text: string): string {
    return getRemovableWord(text, true);
  },
  getForward: function (text: string): string {
    return getRemovableWord(text, false);
  }
};
module.exports = DraftRemovableWord;