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

ShowDiff plugin for @atlaskit/editor-core

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.simplifyChangesWithAttribution = exports.collapseOverlappingChanges = void 0;
var _defineProperty2 = _interopRequireDefault(require("@babel/runtime/helpers/defineProperty"));
var _toConsumableArray2 = _interopRequireDefault(require("@babel/runtime/helpers/toConsumableArray"));
var _prosemirrorChangeset = require("prosemirror-changeset");
var _attributions = require("../decorations/colorSchemes/attributions");
var _optimizeChanges = require("./optimizeChanges");
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) { (0, _defineProperty2.default)(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; }
/**
 * A change, plus the block nodes it owns when it is one piece of a split — a piece's own range no
 * longer covers the container it opened. Absent on an unsplit change, which decorates the blocks
 * inside its own range as before.
 */

var getAttributionIdentity = function getAttributionIdentity(change) {
  var identities = new Set();
  for (var _i = 0, _arr = [].concat((0, _toConsumableArray2.default)(change.deleted), (0, _toConsumableArray2.default)(change.inserted)); _i < _arr.length; _i++) {
    var span = _arr[_i];
    identities.add((0, _attributions.getAttributionKey)(span.data));
  }
  if (identities.size > 1) {
    return {
      key: undefined,
      mergeable: false
    };
  }
  return {
    key: identities.values().next().value,
    mergeable: true
  };
};
var hasContributor = function hasContributor(change) {
  return [].concat((0, _toConsumableArray2.default)(change.deleted), (0, _toConsumableArray2.default)(change.inserted)).some(function (span) {
    return (0, _attributions.getAttributionKey)(span.data) !== undefined;
  });
};
var byNewDocRange = function byNewDocRange(left, right) {
  return left.fromB - right.fromB || left.toB - right.toB;
};

/** Union of the given ranges, with overlapping and touching ones merged. */
var mergeRanges = function mergeRanges(ranges) {
  return (0, _toConsumableArray2.default)(ranges).sort(function (left, right) {
    return left.from - right.from;
  }).reduce(function (merged, range) {
    var last = merged[merged.length - 1];
    if (last && range.from <= last.to) {
      last.to = Math.max(last.to, range.to);
      return merged;
    }
    return [].concat((0, _toConsumableArray2.default)(merged), [_objectSpread({}, range)]);
  }, []);
};

/** Whether `inner` sits wholly inside `outer` and covers less of the document. */
var isContained = function isContained(outer, inner) {
  return inner.toB > inner.fromB && outer.fromB <= inner.fromB && inner.toB <= outer.toB && inner.toB - inner.fromB < outer.toB - outer.fromB;
};

/**
 * The block nodes in `change` whose opening position `ownsPosition` claims. Ownership is by opening
 * position so a block another contributor added inside a container is not claimed by whoever opened
 * the container. `undefined` for a range this document cannot resolve, which falls the piece back
 * to decorating its own range.
 */
var blockNodeRanges = function blockNodeRanges(doc, change, ownsPosition) {
  if (!doc || change.from >= change.to || change.to > doc.content.size) {
    return undefined;
  }
  var ranges = [];
  doc.nodesBetween(change.from, change.to, function (node, pos) {
    if (node.isBlock && ownsPosition(pos) && pos + node.nodeSize <= change.to) {
      ranges.push({
        from: pos,
        to: pos + node.nodeSize
      });
    }
    return true;
  });
  return ranges;
};

/**
 * Splits a change whose spans name more than one contributor into one change per run of consecutive
 * spans sharing a key.
 *
 * `prosemirror-changeset` merges contiguous inserted content into one change while keeping per-span
 * data, so a panel inserted by one contributor and edited inside by another arrives as a single
 * change holding every span — and the latest-writer rule credited all of it, panel included, to
 * whoever wrote last (EDITOR-8932).
 */
var splitMixedIdentityChanges = function splitMixedIdentityChanges(changes, doc) {
  return changes.flatMap(function (change) {
    var _change$inserted$;
    // A replacement can carry an anonymous deletion and an authored insertion. The deleted side
    // needs its own zero-width change or the insertion's actor claims the deletion too.
    var deletedKeys = new Set(change.deleted.map(function (span) {
      return (0, _attributions.getAttributionKey)(span.data);
    }));
    var firstInsertedKey = (0, _attributions.getAttributionKey)((_change$inserted$ = change.inserted[0]) === null || _change$inserted$ === void 0 ? void 0 : _change$inserted$.data);
    var detachDeleted = change.deleted.length > 0 && change.inserted.length > 0 && deletedKeys.size === 1 && !deletedKeys.has(firstInsertedKey) && (deletedKeys.has(undefined) || firstInsertedKey === undefined);
    var deletedChange = detachDeleted ? [_objectSpread(_objectSpread({}, change), {}, {
      toB: change.fromB,
      inserted: []
    })] : [];
    var contentChange = detachDeleted ? _objectSpread(_objectSpread({}, change), {}, {
      fromA: change.toA,
      deleted: []
    }) : change;
    if (getAttributionIdentity(contentChange).mergeable) {
      return [].concat(deletedChange, [contentChange]);
    }
    var runs = [];
    var offset = contentChange.fromB;
    var _iterator = _createForOfIteratorHelper(contentChange.inserted),
      _step;
    try {
      for (_iterator.s(); !(_step = _iterator.n()).done;) {
        var span = _step.value;
        var key = (0, _attributions.getAttributionKey)(span.data);
        var last = runs[runs.length - 1];
        if (last && last.key === key) {
          last.to = offset + span.length;
          last.spans.push(span);
        } else {
          runs.push({
            key: key,
            from: offset,
            to: offset + span.length,
            spans: [span]
          });
        }
        offset += span.length;
      }

      // The offsets above are only positions if the spans partition the inserted range.
    } catch (err) {
      _iterator.e(err);
    } finally {
      _iterator.f();
    }
    if (runs.length < 2 || offset !== contentChange.toB) {
      return [].concat(deletedChange, [contentChange]);
    }
    return [].concat(deletedChange, (0, _toConsumableArray2.default)(runs.map(function (run, index) {
      var owned = blockNodeRanges(doc, {
        from: contentChange.fromB,
        to: contentChange.toB
      }, function (pos) {
        return pos >= run.from && pos < run.to;
      });
      return _objectSpread(_objectSpread({}, contentChange), {}, {
        fromA: index === 0 ? contentChange.fromA : contentChange.toA,
        fromB: run.from,
        toB: run.to,
        deleted: index === 0 ? contentChange.deleted : [],
        inserted: run.spans
      }, owned ? {
        blockNodeRangesB: owned
      } : {});
    })));
  });
};

/**
 * Subtracts every differently attributed contained change from a change's range, including when
 * one has no contributor. Applies when the changes arrive separately rather than as spans of one —
 * the `step` diff type. A contained change by the same author, and one that only partially
 * overlaps, are left for the collapse below.
 *
 * The leading fragment keeps the deleted side, so one deletion is not drawn once per fragment.
 */
var splitContainedChanges = function splitContainedChanges(changes, doc) {
  return changes.flatMap(function (change) {
    var _getAttributionIdenti = getAttributionIdentity(change),
      key = _getAttributionIdenti.key,
      mergeable = _getAttributionIdenti.mergeable;
    var inner = mergeRanges(changes.filter(function (other) {
      var otherIdentity = getAttributionIdentity(other);
      return other !== change && mergeable && otherIdentity.mergeable && otherIdentity.key !== key && isContained(change, other);
    }).map(function (_ref) {
      var fromB = _ref.fromB,
        toB = _ref.toB;
      return {
        from: fromB,
        to: toB
      };
    }));
    if (inner.length === 0) {
      return [change];
    }
    var gaps = [];
    var cursor = change.fromB;
    var _iterator2 = _createForOfIteratorHelper(inner),
      _step2;
    try {
      for (_iterator2.s(); !(_step2 = _iterator2.n()).done;) {
        var _step2$value = _step2.value,
          from = _step2$value.from,
          to = _step2$value.to;
        if (from > cursor) {
          gaps.push({
            from: cursor,
            to: from
          });
        }
        cursor = Math.max(cursor, to);
      }
    } catch (err) {
      _iterator2.e(err);
    } finally {
      _iterator2.f();
    }
    if (change.toB > cursor) {
      gaps.push({
        from: cursor,
        to: change.toB
      });
    }

    // Subtracted end to end, so nothing is left to highlight — but the blocks are still owned.
    var fragments = gaps.length > 0 ? gaps : [{
      from: change.toB,
      to: change.toB
    }];
    // The outer author's: every block in their range that no inner change opened.
    var owned = blockNodeRanges(doc, {
      from: change.fromB,
      to: change.toB
    }, function (pos) {
      return !inner.some(function (_ref2) {
        var from = _ref2.from,
          to = _ref2.to;
        return pos >= from && pos < to;
      });
    });
    return fragments.map(function (fragment, index) {
      return _objectSpread(_objectSpread({}, change), {}, {
        fromA: index === 0 ? change.fromA : change.toA,
        fromB: fragment.from,
        toB: fragment.to,
        deleted: index === 0 ? change.deleted : []
      }, owned ? {
        blockNodeRangesB: index === 0 ? owned : []
      } : {});
    });
  });
};

/**
 * The blocks a merged change owns. Both sides must name theirs, or the merge falls back to its own
 * range — narrowing it could drop a block altogether.
 */
var mergeBlockNodeRanges = function mergeBlockNodeRanges(left, right) {
  return left.blockNodeRangesB && right.blockNodeRangesB ? [].concat((0, _toConsumableArray2.default)(left.blockNodeRangesB), (0, _toConsumableArray2.default)(right.blockNodeRangesB)) : undefined;
};

/** Unions overlapping changes, except when only one side names a contributor. */
var collapse = function collapse(changes) {
  // A zero-length new-document range paints no inline decoration, so it is kept aside rather than
  // folded into a neighbouring insertion.
  var emptyRanges = changes.filter(function (change) {
    return change.toB <= change.fromB;
  });
  var collapsed = [];
  var _iterator3 = _createForOfIteratorHelper(changes.filter(function (change) {
      return change.toB > change.fromB;
    }).sort(byNewDocRange)),
    _step3;
  try {
    for (_iterator3.s(); !(_step3 = _iterator3.n()).done;) {
      var change = _step3.value;
      var current = collapsed[collapsed.length - 1];
      var currentHasContributor = current && hasContributor(current);
      var changeHasContributor = hasContributor(change);
      if (current && change.fromB < current.toB && currentHasContributor === changeHasContributor) {
        var blockNodeRangesB = mergeBlockNodeRanges(current, change);
        collapsed[collapsed.length - 1] = _objectSpread({
          fromA: Math.min(current.fromA, change.fromA),
          toA: Math.max(current.toA, change.toA),
          fromB: Math.min(current.fromB, change.fromB),
          toB: Math.max(current.toB, change.toB),
          deleted: [].concat((0, _toConsumableArray2.default)(current.deleted), (0, _toConsumableArray2.default)(change.deleted)),
          inserted: [].concat((0, _toConsumableArray2.default)(current.inserted), (0, _toConsumableArray2.default)(change.inserted))
        }, blockNodeRangesB ? {
          blockNodeRangesB: blockNodeRangesB
        } : {});
      } else {
        collapsed.push(_objectSpread({}, change));
      }
    }
  } catch (err) {
    _iterator3.e(err);
  } finally {
    _iterator3.f();
  }
  return [].concat(collapsed, (0, _toConsumableArray2.default)(emptyRanges)).sort(byNewDocRange);
};

/**
 * Collapses changes whose new-document ranges strictly overlap. Attribution runs are simplified
 * independently, so runs either side of an unattributed step can come back covering the same
 * characters — which stacks two inline decorations and renders one contributor tag per copy.
 *
 * Merging keeps every span from both sides, so the latest-writer rule still decides whose tag is
 * shown among attributed edits. An unattributed change never merges with an attributed one.
 * Ranges that merely touch are left alone.
 *
 * Contributors are separated first, by `splitMixedIdentityChanges` and `splitContainedChanges`.
 * Both leave ranges that only touch, so they survive the collapse.
 *
 * Carries no gate of its own: the only caller reaches it through the attributed changeset, which
 * already requires `confluence_ncs_step_diffing_version_history`.
 */
var collapseOverlappingChanges = exports.collapseOverlappingChanges = function collapseOverlappingChanges(changes, doc) {
  return collapse(splitContainedChanges(splitMixedIdentityChanges(changes, doc), doc));
};

/**
 * Simplifies and optimizes consecutive changes without crossing an attribution boundary.
 * A change which already contains more than one identity is deliberately kept isolated.
 */
var simplifyChangesWithAttribution = exports.simplifyChangesWithAttribution = function simplifyChangesWithAttribution(changes, doc) {
  var result = [];
  var run = [];
  var runIdentity;
  var flush = function flush() {
    if (run.length > 0) {
      // Some show-diff producers use structurally compatible Change objects rather than the
      // library class. `simplifyChanges` reads runtime `lenA`/`lenB` getters even though they
      // are intentionally omitted from its public declarations, so add equivalent getters
      // without calling the library's internal constructor.
      var normalizedRun = run.map(function (change) {
        return _objectSpread(_objectSpread({}, change), {}, {
          get lenA() {
            return change.toA - change.fromA;
          },
          get lenB() {
            return change.toB - change.fromB;
          }
        });
      });
      result.push.apply(result, (0, _toConsumableArray2.default)((0, _optimizeChanges.optimizeChanges)((0, _prosemirrorChangeset.simplifyChanges)(normalizedRun, doc))));
    }
    run = [];
    runIdentity = undefined;
  };
  var _iterator4 = _createForOfIteratorHelper(changes),
    _step4;
  try {
    for (_iterator4.s(); !(_step4 = _iterator4.n()).done;) {
      var _runIdentity;
      var change = _step4.value;
      var identity = getAttributionIdentity(change);
      var canJoinRun = ((_runIdentity = runIdentity) === null || _runIdentity === void 0 ? void 0 : _runIdentity.mergeable) === true && identity.mergeable && runIdentity.key === identity.key;
      if (run.length > 0 && !canJoinRun) {
        flush();
      }
      run.push(change);
      runIdentity = identity;
      if (!identity.mergeable) {
        flush();
      }
    }
  } catch (err) {
    _iterator4.e(err);
  } finally {
    _iterator4.f();
  }
  flush();
  return result;
};