@atlaskit/editor-plugin-show-diff/dist/cjs/pm-plugins/calculateDiff/simplifySteps.js

ShowDiff plugin for @atlaskit/editor-core

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.simplifySteps = simplifySteps;
var _steps = require("@atlaskit/adf-schema/steps");
var _document = require("@atlaskit/editor-common/utils/document");
var _transform = require("@atlaskit/editor-prosemirror/transform");
function _createForOfIteratorHelper(r, e) { var t = "undefined" != typeof Symbol && r[Symbol.iterator] || r["@@iterator"]; if (!t) { if (Array.isArray(r) || (t = _unsupportedIterableToArray(r)) || e && r && "number" == typeof r.length) { t && (r = t); var _n = 0, F = function F() {}; return { s: F, n: function n() { return _n >= r.length ? { done: !0 } : { done: !1, value: r[_n++] }; }, e: function e(r) { throw r; }, f: F }; } throw new TypeError("Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); } var o, a = !0, u = !1; return { s: function s() { t = t.call(r); }, n: function n() { var r = t.next(); return a = r.done, r; }, e: function e(r) { u = !0, o = r; }, f: function f() { try { a || null == t.return || t.return(); } finally { if (u) throw o; } } }; }
function _unsupportedIterableToArray(r, a) { if (r) { if ("string" == typeof r) return _arrayLikeToArray(r, a); var t = {}.toString.call(r).slice(8, -1); return "Object" === t && r.constructor && (t = r.constructor.name), "Map" === t || "Set" === t ? Array.from(r) : "Arguments" === t || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(t) ? _arrayLikeToArray(r, a) : void 0; } }
function _arrayLikeToArray(r, a) { (null == a || a > r.length) && (a = r.length); for (var e = 0, n = Array(a); e < a; e++) n[e] = r[e]; return n; }
/**
 * Attempts to merge two consecutive ReplaceStep operations.
 * This merges steps where:
 * - Both steps replace content at the same starting position
 * - The second step's range encompasses the first step's range
 * - The second step has content to insert
 * Returns null if steps cannot be merged.
 */
function mergeReplaceSteps(step1, step2) {
  if (!(step1 instanceof _transform.ReplaceStep) || !(step2 instanceof _transform.ReplaceStep)) {
    return null;
  }
  // Confirm the step overlaps exactly with the previous
  var step2Length = step2.to - step2.from;
  if (step1.from === step2.from && step2.to >= step1.to && step2.slice.size >= step2Length && step2Length === step1.slice.size && step2.slice.size >= step1.slice.size && step1.slice.openEnd === step2.slice.openEnd && step1.slice.openStart === step2.slice.openStart) {
    return new _transform.ReplaceStep(step1.from, step1.to, step2.slice);
  }
  return null;
}

// Simplifies the steps to improve performance and reduce fragmentation in diffs
function simplifySteps(steps, originalDoc) {
  var stepsToFilter = removeUnusedSteps(steps, originalDoc);
  return stepsToFilter
  // Remove steps that don't affect document structure or content
  .filter(function (step) {
    return !(step instanceof _steps.AnalyticsStep);
  })
  // Merge consecutive steps where possible
  .reduce(function (acc, step) {
    var _lastStep$merge, _lastStep$merge2;
    var lastStep = acc[acc.length - 1];
    var merged = (_lastStep$merge = lastStep === null || lastStep === void 0 || (_lastStep$merge2 = lastStep.merge) === null || _lastStep$merge2 === void 0 ? void 0 : _lastStep$merge2.call(lastStep, step)) !== null && _lastStep$merge !== void 0 ? _lastStep$merge : mergeReplaceSteps(lastStep, step);
    if (merged) {
      acc[acc.length - 1] = merged;
    } else {
      acc.push(step);
    }
    return acc;
  }, []);
}

/**
 * Does a first pass to remove steps that don't impact the document
 */
function removeUnusedSteps(steps, originalDoc) {
  var finalSteps = [];
  var firstPassDoc = originalDoc;
  var _iterator = _createForOfIteratorHelper(steps),
    _step;
  try {
    for (_iterator.s(); !(_step = _iterator.n()).done;) {
      var step = _step.value;
      var result = step.apply(firstPassDoc);
      if (result.failed === null && result.doc && !(0, _document.areNodesEqualIgnoreAttrs)(firstPassDoc, result.doc, ['localId'])) {
        finalSteps.push(step);
        firstPassDoc = result.doc;
      }
    }
  } catch (err) {
    _iterator.e(err);
  } finally {
    _iterator.f();
  }
  return finalSteps;
}