Update removedAt for already deleted nodes during range deletions

packages/sdk/src/document/crdt/tree.ts

@@ -14,36 +14,36 @@
  * limitations under the License.
  */
 
+import { CRDTElement } from '@yorkie-js-sdk/src/document/crdt/element';
 import {
-  TimeTicket,
   InitialTimeTicket,
-  TimeTicketStruct,
   MaxTimeTicket,
+  TimeTicket,
+  TimeTicketStruct,
 } from '@yorkie-js-sdk/src/document/time/ticket';
-import { CRDTElement } from '@yorkie-js-sdk/src/document/crdt/element';
 
+import type * as Devtools from '@yorkie-js-sdk/src/devtools/types';
+import { GCChild, GCPair, GCParent } from '@yorkie-js-sdk/src/document/crdt/gc';
+import { Indexable } from '@yorkie-js-sdk/src/document/document';
+import { escapeString } from '@yorkie-js-sdk/src/document/json/strings';
+import { Comparator } from '@yorkie-js-sdk/src/util/comparator';
+import { Code, YorkieError } from '@yorkie-js-sdk/src/util/error';
+import type {
+  DefaultTextType,
+  TreeNodeType,
+  TreeToken,
+} from '@yorkie-js-sdk/src/util/index_tree';
 import {
   IndexTree,
-  TreePos,
   IndexTreeNode,
-  traverseAll,
   TokenType,
+  TreePos,
+  traverseAll,
 } from '@yorkie-js-sdk/src/util/index_tree';
-import { RHT, RHTNode } from './rht';
-import { ActorID } from './../time/actor_id';
 import { LLRBTree } from '@yorkie-js-sdk/src/util/llrb_tree';
-import { Comparator } from '@yorkie-js-sdk/src/util/comparator';
 import { parseObjectValues } from '@yorkie-js-sdk/src/util/object';
-import type {
-  DefaultTextType,
-  TreeNodeType,
-  TreeToken,
-} from '@yorkie-js-sdk/src/util/index_tree';
-import { Indexable } from '@yorkie-js-sdk/src/document/document';
-import type * as Devtools from '@yorkie-js-sdk/src/devtools/types';
-import { escapeString } from '@yorkie-js-sdk/src/document/json/strings';
-import { GCChild, GCPair, GCParent } from '@yorkie-js-sdk/src/document/crdt/gc';
-import { Code, YorkieError } from '@yorkie-js-sdk/src/util/error';
+import { ActorID } from './../time/actor_id';
+import { RHT, RHTNode } from './rht';
 
 /**
  * `TreeNode` represents a node in the tree.
@@ -1094,6 +1094,9 @@ export class CRDTTree extends CRDTElement implements GCParent {
             nodesToBeRemoved.push(node);
           }
           tokensToBeRemoved.push([node, tokenType]);
+        } else if (node.isRemoved && editedAt.after(node.removedAt!)) {
+          node.removedAt = editedAt;
+          pairs.push({ parent: this, child: node });
         }
       },
     );
@@ -1371,8 +1374,8 @@ export class CRDTTree extends CRDTElement implements GCParent {
       const treePos = node.isText
         ? { node, offset: 0 }
         : parentNode && leftChildNode
-          ? this.toTreePos(parentNode, leftChildNode)
-          : null;
+        ? this.toTreePos(parentNode, leftChildNode)
+        : null;
 
       if (treePos) {
         index = this.indexTree.indexOf(treePos);

packages/sdk/test/helper/helper.ts

@@ -187,7 +187,7 @@ export async function assertThrowsAsync(
   message?: string,
 ) {
   // eslint-disable-next-line @typescript-eslint/no-empty-function
-  let errFn = () => {};
+  let errFn = () => { };
   try {
     await fn();
   } catch (e) {
@@ -285,3 +285,10 @@ export function posT(offset = 0): CRDTTreeNodeID {
 export function timeT(): TimeTicket {
   return dummyContext.issueTimeTicket();
 }
+
+/**
+ * `getLTT` is a helpher function that returns the last time ticket.
+ */
+export function getLTT(): TimeTicket {
+  return dummyContext.getLastTimeTicket();
+}

packages/sdk/test/unit/document/crdt/tree_test.ts

@@ -28,7 +28,7 @@ import {
   TreeNodeForTest,
 } from '@yorkie-js-sdk/src/document/crdt/tree';
 import { stringifyObjectValues } from '@yorkie-js-sdk/src/util/object';
-import { idT, posT, timeT } from '@yorkie-js-sdk/test/helper/helper';
+import { idT, posT, timeT, getLTT } from '@yorkie-js-sdk/test/helper/helper';
 
 describe('CRDTTreeNode', function () {
   it('Can be created', function () {
@@ -231,6 +231,37 @@ describe('CRDTTree.Edit', function () {
     );
     assert.equal(t.toIndex(parent, left), 0);
   });
+
+  it('Update removedAt for already deleted nodes during range deletions', function () {
+    //       0
+    // <root> </root>
+    const t = new CRDTTree(new CRDTTreeNode(posT(), 'r'), timeT());
+    assert.equal(t.getRoot().size, 0);
+    assert.equal(t.toXML(), /*html*/ `<r></r>`);
+
+    //           1
+    // <root> <p> h e l l o </p> </root>
+    const p = new CRDTTreeNode(posT(), 'p', []);
+    const txt = new CRDTTreeNode(posT(), 'text', 'hello');
+    p.insertAt(txt, 0);
+    t.editT([0, 0], [p], 0, timeT(), timeT);
+    assert.equal(t.toXML(), /*html*/ `<r><p>hello</p></r>`);
+
+    //           2
+    // <root> <p> </p> </root>
+    t.editT([1, 6], undefined, 0, timeT(), timeT);
+    assert.equal(t.toXML(), /*html*/ `<r><p></p></r>`);
+    assert.isFalse(p.isRemoved);
+    assert.isTrue(txt.getRemovedAt()?.equals(getLTT()));
+
+    //           3
+    // <root> </root>
+    t.editT([0, 2], undefined, 0, timeT(), timeT);
+    assert.equal(t.toXML(), /*html*/ `<r></r>`);
+    assert.isTrue(p.getRemovedAt()?.equals(getLTT()));
+    assert.isTrue(txt.getRemovedAt()?.equals(getLTT()));
+  });
+
 });
 
 describe('CRDTTree.Split', function () {