@atlaskit/editor-plugin-code-block-advanced/dist/esm/nodeviews/codemirrorSync/updateCMSelection.js

CodeBlockAdvanced plugin for @atlaskit/editor-core

import { expValEquals } from '@atlaskit/tmp-editor-statsig/exp-val-equals';
/**
 *
 * Compares the updated text with the current to determine the transaction to fire
 * in the CodeMirror editor.
 *
 * @param curText string - the current CodeMirror text
 * @param newText string - the new ProseMirror text
 * @returns The changes or undefined if no change
 */

var N_LINE_FEED = '\n'.charCodeAt(0);
var R_LINE_FEED = '\r'.charCodeAt(0);

/**
 * Example of CRLF differences:
 * newText: 'abc\r\ndef\r\nghi'
 * curText: 'abc\ndef\nghi'
 */
export var getCMSelectionChanges = function getCMSelectionChanges(curText, newText) {
  if (newText !== curText) {
    var curStart = 0,
      newStart = 0;
    var start = 0,
      curEnd = curText.length,
      newEnd = newText.length;
    if (expValEquals('platform_editor_fix_advanced_codeblocks_crlf_patch', 'isEnabled', true)) {
      while (curStart < curEnd && (curText.charCodeAt(curStart) === newText.charCodeAt(newStart) || newText.charCodeAt(newStart) === R_LINE_FEED && curText.charCodeAt(curStart) === N_LINE_FEED)) {
        if (newText.charCodeAt(newStart) === R_LINE_FEED && curText.charCodeAt(curStart) === N_LINE_FEED && newText.charCodeAt(newStart + 1) === N_LINE_FEED) {
          newStart++;
        }
        curStart++;
        newStart++;
      }
      while (curEnd > curStart && newEnd > newStart && (curText.charCodeAt(curEnd - 1) === newText.charCodeAt(newEnd - 1) || newText.charCodeAt(newEnd - 1) === N_LINE_FEED && curText.charCodeAt(curEnd - 1) === N_LINE_FEED)) {
        if (newText.charCodeAt(newEnd - 1) === N_LINE_FEED && curText.charCodeAt(curEnd - 1) === N_LINE_FEED && newText.charCodeAt(newEnd - 2) === R_LINE_FEED) {
          newEnd--;
        }
        curEnd--;
        newEnd--;
      }
      return {
        from: curStart,
        to: curEnd,
        insert: newText.slice(newStart, newEnd)
      };
    } else {
      while (start < curEnd && curText.charCodeAt(start) === newText.charCodeAt(start)) {
        ++start;
      }
      while (curEnd > start && newEnd > start && curText.charCodeAt(curEnd - 1) === newText.charCodeAt(newEnd - 1)) {
        curEnd--;
        newEnd--;
      }
      return {
        from: start,
        to: curEnd,
        insert: newText.slice(start, newEnd)
      };
    }
  }
};