xlsx-official

# Excel Generation ## Option A — ExcelJS (Feature-Rich) ```bash npm install exceljs npm install -D @types/node ``` ```typescript // lib/excel/report.excel.ts import ExcelJS from 'exceljs' export async function generateExcelReport(data: ReportData): Promise<Buffer> { const workbook = new ExcelJS.Workbook() workbook.creator = 'Full Stack HQ' workbook.lastModifiedBy = 'system' workbook.created = new Date() workbook.modified = new Date() const sheet = workbook.addWorksheet('Report', { pageSetup: { paperSize: 9, // A4 orientation: 'landscape', fitToPage: true, }, views: [{ state: 'frozen', xSplit: 0, ySplit: 1 }], // freeze header row }) // ─── Column Definitions ─────────────────────────────────── sheet.columns = data.columns.map(col => ({ header: col.header, key: col.key, width: col.width ?? 20, style: { alignment: { horizontal: col.align ?? 'left', wrapText: false }, numFmt: col.format, // e.g. '#,##0.00', 'yyyy-mm-dd' }, })) // ─── Style the Header Row ───────────────────────────────── const headerRow = sheet.getRow(1) headerRow.eachCell(cell => { cell.fill = { type: 'pattern', pattern: 'solid', fgColor: { argb: 'FF2563EB' }, } cell.font = { name: 'Calibri', size: 11, bold: true, color: { argb: 'FFFFFFFF' }, } cell.border = { bottom: { style: 'medium', color: { argb: 'FF1D4ED8' } }, ...