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

ShowDiff plugin for @atlaskit/editor-core

import _defineProperty from "@babel/runtime/helpers/defineProperty";
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; }
function ownKeys(e, r) { var t = Object.keys(e); if (Object.getOwnPropertySymbols) { var o = Object.getOwnPropertySymbols(e); r && (o = o.filter(function (r) { return Object.getOwnPropertyDescriptor(e, r).enumerable; })), t.push.apply(t, o); } return t; }
function _objectSpread(e) { for (var r = 1; r < arguments.length; r++) { var t = null != arguments[r] ? arguments[r] : {}; r % 2 ? ownKeys(Object(t), !0).forEach(function (r) { _defineProperty(e, r, t[r]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(e, Object.getOwnPropertyDescriptors(t)) : ownKeys(Object(t)).forEach(function (r) { Object.defineProperty(e, r, Object.getOwnPropertyDescriptor(t, r)); }); } return e; }
import { AnalyticsStep } from '@atlaskit/adf-schema/steps/analytics';
import { areNodesEqualIgnoreAttrs } from '@atlaskit/editor-common/utils/document';
import { ReplaceStep } from '@atlaskit/editor-prosemirror/transform';
import { getAttributionKey } from '../decorations/colorSchemes/attributions';
/**
 * 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 ReplaceStep) || !(step2 instanceof 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 ReplaceStep(step1.from, step1.to, step2.slice);
  }
  return null;
}

// Simplifies the steps to improve performance and reduce fragmentation in diffs
export 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 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;
  }, []);
}
var mergeAttributions = function mergeAttributions(first, second) {
  var _second$wasOffline;
  if (!first) {
    return second;
  }
  if (!second) {
    return first;
  }
  return _objectSpread(_objectSpread(_objectSpread({}, first), second), {}, {
    wasOffline: first.wasOffline === true || second.wasOffline === true ? true : (_second$wasOffline = second.wasOffline) !== null && _second$wasOffline !== void 0 ? _second$wasOffline : first.wasOffline
  });
};

/**
 * Attribution-preserving variant of `simplifySteps`.
 *
 * Steps may only merge when they have the same effective actor identity. Keeping the attribution
 * coupled to the step also ensures filtering a no-op/analytics step cannot shift array indexes.
 */
export function simplifyStepsWithAttribution(steps, stepAttributions, originalDoc) {
  var stepsToFilter = removeUnusedAttributedSteps(steps.map(function (step, index) {
    return {
      step: step,
      stepAttribution: stepAttributions[index]
    };
  }), originalDoc);
  return stepsToFilter.filter(function (_ref) {
    var step = _ref.step;
    return !(step instanceof AnalyticsStep);
  }).reduce(function (acc, current) {
    var _previous$step$merge, _previous$step$merge2, _previous$step;
    var previous = acc[acc.length - 1];
    var isSameIdentity = previous && getAttributionKey(previous.stepAttribution) === getAttributionKey(current.stepAttribution);
    var merged = isSameIdentity ? (_previous$step$merge = (_previous$step$merge2 = (_previous$step = previous.step).merge) === null || _previous$step$merge2 === void 0 ? void 0 : _previous$step$merge2.call(_previous$step, current.step)) !== null && _previous$step$merge !== void 0 ? _previous$step$merge : mergeReplaceSteps(previous.step, current.step) : null;
    if (merged) {
      acc[acc.length - 1] = {
        step: merged,
        stepAttribution: mergeAttributions(previous.stepAttribution, current.stepAttribution)
      };
    } else {
      acc.push(current);
    }
    return acc;
  }, []);
}

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

/**
 * Does a first pass to remove steps that don't impact the document
 */
function removeUnusedSteps(steps, originalDoc) {
  var finalSteps = [];
  var firstPassDoc = originalDoc;
  var _iterator2 = _createForOfIteratorHelper(steps),
    _step2;
  try {
    for (_iterator2.s(); !(_step2 = _iterator2.n()).done;) {
      var step = _step2.value;
      var result = step.apply(firstPassDoc);
      if (result.failed === null && result.doc && !areNodesEqualIgnoreAttrs(firstPassDoc, result.doc, ['localId'])) {
        finalSteps.push(step);
        firstPassDoc = result.doc;
      }
    }
  } catch (err) {
    _iterator2.e(err);
  } finally {
    _iterator2.f();
  }
  return finalSteps;
}