fix: handle empty sections in parseDataStreamToTree by ensuring an … (#6188)

packages/engine-render/src/components/docs/view-model/__tests__/document-view-model.spec.ts

@@ -0,0 +1,50 @@
+/**
+ * Copyright 2023-present DreamNum Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { DataStreamTreeNodeType, DataStreamTreeTokenType } from '@univerjs/core';
+import { describe, expect, it } from 'vitest';
+import { parseDataStreamToTree } from '../document-view-model';
+
+describe('DocumentViewModel', () => {
+    describe('parseDataStreamToTree', () => {
+        it('should handle empty section correctly', () => {
+            const dataStream = DataStreamTreeTokenType.SECTION_BREAK;
+            const { sectionList } = parseDataStreamToTree(dataStream);
+
+            expect(sectionList.length).toBe(1);
+            const section = sectionList[0];
+            expect(section.nodeType).toBe(DataStreamTreeNodeType.SECTION_BREAK);
+            expect(section.children.length).toBe(1);
+            expect(section.children[0].nodeType).toBe(DataStreamTreeNodeType.PARAGRAPH);
+            expect(section.children[0].content).toBe('');
+        });
+
+        it('should handle consecutive section breaks correctly', () => {
+            const dataStream = `Hello${DataStreamTreeTokenType.PARAGRAPH}${DataStreamTreeTokenType.SECTION_BREAK}${DataStreamTreeTokenType.SECTION_BREAK}`;
+            const { sectionList } = parseDataStreamToTree(dataStream);
+
+            expect(sectionList.length).toBe(2);
+
+            // First section
+            expect(sectionList[0].children.length).toBe(1);
+            expect(sectionList[0].children[0].content).toBe(`Hello${DataStreamTreeTokenType.PARAGRAPH}${DataStreamTreeTokenType.SECTION_BREAK}`);
+
+            // Second section (empty)
+            expect(sectionList[1].children.length).toBe(1);
+            expect(sectionList[1].children[0].content).toBe('');
+        });
+    });
+});

packages/engine-render/src/components/docs/view-model/document-view-model.ts

@@ -111,6 +111,12 @@ export function parseDataStreamToTree(dataStream: string, tables?: ICustomTable[
             const sectionNode = DataStreamTreeNode.create(DataStreamTreeNodeType.SECTION_BREAK);
             const tempParagraphList = tableCellList.length > 0 ? cellParagraphList : paragraphList;
 
+            if (tempParagraphList.length === 0) {
+                const emptyParagraph = DataStreamTreeNode.create(DataStreamTreeNodeType.PARAGRAPH, '');
+                emptyParagraph.setIndexRange(i, i - 1);
+                tempParagraphList.push(emptyParagraph);
+            }
+
             batchParent(sectionNode, tempParagraphList);
 
             const lastNode = tempParagraphList[tempParagraphList.length - 1];