handsontable/translations/changesObservable/utils.js

Handsontable is a JavaScript Spreadsheet Component available for React, Angular and Vue.

"use strict";

exports.__esModule = true;
exports.arrayDiff = arrayDiff;

/**
 * An array diff implementation. The function iterates through the arrays and depends
 * on the diff results, collect the changes as a list of the objects.
 *
 * Each object contains information about the differences in the indexes of the arrays.
 * The changes also contain data about the new and previous array values.
 *
 * @private
 * @param {Array} baseArray The base array to diff from.
 * @param {Array} newArray The new array to compare with.
 * @returns {Array}
 */
function arrayDiff(baseArray, newArray) {
  var changes = [];
  var i = 0;
  var j = 0;
  /* eslint-disable no-plusplus */

  for (; i < baseArray.length && j < newArray.length; i++, j++) {
    if (baseArray[i] !== newArray[j]) {
      changes.push({
        op: 'replace',
        index: j,
        oldValue: baseArray[i],
        newValue: newArray[j]
      });
    }
  }

  for (; i < newArray.length; i++) {
    changes.push({
      op: 'insert',
      index: i,
      oldValue: void 0,
      newValue: newArray[i]
    });
  }

  for (; j < baseArray.length; j++) {
    changes.push({
      op: 'remove',
      index: j,
      oldValue: baseArray[j],
      newValue: void 0
    });
  }

  return changes;
}