Fixing the error when importing a large Excel file

apps/api/src/common/excel.ts

@@ -1,5 +1,6 @@
 import { BadRequestException } from '@nestjs/common';
 import ExcelJS from 'exceljs';
+import { EXCEL_IMPORT_LARGE_THRESHOLD } from './excel-import-session';
 
 export function cellStr(value: ExcelJS.CellValue | undefined): string {
   try {
@@ -229,6 +230,8 @@ export type ExcelPreviewResult = {
   fields: ExcelFieldOption[];
   suggested: Record<string, string>;
   needsMapping: boolean;
+  rowCount: number;
+  largeFile?: boolean;
 };
 
 export function excelFieldsFromColumns(
@@ -315,11 +318,25 @@ export async function previewExcel(
   const mapped = new Set(Object.values(suggested));
   const missingRequired = required.some((key) => !mapped.has(key));
   const unrecognized = columns.some((col) => !suggested[col.header]);
+
+  let rowCount = 0;
+  sheet.eachRow((row, rowNumber) => {
+    if (rowNumber === 1) return;
+    let any = false;
+    row.eachCell((cell) => {
+      if (any) return;
+      if (cellStr(cell.value)) any = true;
+    });
+    if (any) rowCount += 1;
+  });
+
   return {
     columns,
     fields,
     suggested,
     needsMapping: unrecognized || missingRequired || !mapped.size,
+    rowCount,
+    largeFile: rowCount >= EXCEL_IMPORT_LARGE_THRESHOLD,
   };
 }