chore: add few Streaming unit tests

Author: ghiscoding

packages/excel-builder-vanilla/src/__tests__/streaming.spec.ts

@@ -0,0 +1,102 @@
+import { describe, expect, it } from 'vitest';
+
+import { createWorkbook } from '../factory.js';
+import { createExcelFileStream } from '../streaming.js';
+import { Worksheet } from '../Excel/Worksheet.js';
+
+// Basic streaming test for NodeJS and browser-like environments
+
+describe('Streaming API', () => {
+  it('should stream Excel file chunks', async () => {
+    const workbook = createWorkbook();
+    const worksheet = workbook.createWorksheet({ name: 'Sheet1' });
+    worksheet.setData([
+      ['Artist', 'Album', 'Price'],
+      ['Buckethead', 'Albino Slug', 8.99],
+      ['Crystal Method', 'Vegas', 10.54],
+    ]);
+    workbook.addWorksheet(worksheet);
+
+    const chunks: Uint8Array[] = [];
+    for await (const chunk of createExcelFileStream(workbook, { chunkSize: 1024 })) {
+      expect(chunk).toBeInstanceOf(Uint8Array);
+      chunks.push(chunk);
+    }
+    // Should produce a non-empty file
+    const totalSize = chunks.reduce((sum, c) => sum + c.length, 0);
+    expect(totalSize).toBeGreaterThan(0);
+  });
+
+  it('should stream Excel file with formulas and styles', async () => {
+    const workbook = createWorkbook();
+    const worksheet = workbook.createWorksheet({ name: 'Sheet2' });
+    worksheet.setData([
+      [{ value: 'Artist' }, { value: 'Price' }, { value: 'Total' }],
+      ['Buckethead', 8.99, { value: 'B2*2', metadata: { type: 'formula' } }],
+      ['Crystal Method', 10.54, { value: 'B3*2', metadata: { type: 'formula' } }],
+    ]);
+    workbook.addWorksheet(worksheet);
+
+    const chunks: Uint8Array[] = [];
+    for await (const chunk of createExcelFileStream(workbook, { chunkSize: 512 })) {
+      expect(chunk).toBeInstanceOf(Uint8Array);
+      chunks.push(chunk);
+    }
+    const totalSize = chunks.reduce((sum, c) => sum + c.length, 0);
+    expect(totalSize).toBeGreaterThan(0);
+  });
+
+  describe('Worksheet XML helpers', () => {
+    it('getWorksheetXmlHeader returns correct header', () => {
+      const ws = new Worksheet({ name: 'Test' });
+      const header = ws.getWorksheetXmlHeader();
+      expect(header).toContain('<?xml version="1.0" encoding="UTF-8" standalone="yes"?>');
+      expect(header).toContain('<worksheet');
+      expect(header).toContain('xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"');
+    });
+
+    it('getWorksheetXmlFooter returns empty string if no header/footer', () => {
+      const ws = new Worksheet({ name: 'Test' });
+      expect(ws.getWorksheetXmlFooter()).toBe('');
+    });
+
+    it('getWorksheetXmlFooter returns headerFooter XML if header/footer set', () => {
+      const ws = new Worksheet({ name: 'Test' });
+      ws.setHeader(['Left', 'Center', 'Right']);
+      ws.setFooter(['FLeft', 'FCenter', 'FRight']);
+      const xml = ws.getWorksheetXmlFooter();
+      expect(xml).toContain('<headerFooter>');
+      expect(xml).toContain('<oddHeader>');
+      expect(xml).toContain('<oddFooter>');
+      expect(xml).toContain('Left');
+      expect(xml).toContain('FLeft');
+    });
+  });
+
+  describe('serializeRows', () => {
+    it('serializes text and number rows correctly', () => {
+      const ws = new Worksheet({ name: 'Test' });
+      ws.sharedStrings = { strings: {}, addString: () => 0 } as any;
+      const rows = [
+        ['Header1', 'Header2'],
+        [123, 'abc'],
+      ];
+      const xml = ws.serializeRows(rows);
+      expect(xml).toContain('<row r="1">');
+      expect(xml).toContain('<c r="A1" t="s"><v>0</v></c>');
+      expect(xml).toContain('<c r="B2" t="s"><v>0</v></c>');
+    });
+
+    it('serializes formula cells', () => {
+      const ws = new Worksheet({ name: 'Test' });
+      ws.sharedStrings = { strings: {}, addString: () => 0 } as any;
+      const rows = [
+        ['Header1', 'Header2'],
+        [{ value: 'A2+B2', metadata: { type: 'formula' } }, 42],
+      ];
+      const xml = ws.serializeRows(rows);
+      expect(xml).toContain('<c r="A2" t="s"><v>0</v></c>');
+      expect(xml).toContain('<c r="B2"><v>42</v></c>');
+    });
+  });
+});