fix: Getting the sheet columns in import sheet

packages/server/src/services/Import/sheet_utils.ts

@@ -0,0 +1,56 @@
+import XLSX from 'xlsx';
+import { first } from 'lodash';
+
+/**
+ * Parses the given sheet buffer to worksheet.
+ * @param {Buffer} buffer
+ * @returns {XLSX.WorkSheet}
+ */
+export function parseFirstSheet(buffer: Buffer): XLSX.WorkSheet {
+  const workbook = XLSX.read(buffer, { type: 'buffer', raw: true });
+
+  const firstSheetName = workbook.SheetNames[0];
+  const worksheet = workbook.Sheets[firstSheetName];
+
+  return worksheet;
+}
+
+/**
+ * Extracts the given worksheet to columns.
+ * @param {XLSX.WorkSheet} worksheet
+ * @returns {Array<string>}
+ */
+export function extractSheetColumns(worksheet: XLSX.WorkSheet): Array<string> {
+  // By default, sheet_to_json scans the first row and uses the values as headers.
+  // With the header: 1 option, the function exports an array of arrays of values.
+  const sheetCells = XLSX.utils.sheet_to_json(worksheet, { header: 1 });
+  const sheetCols = first(sheetCells) as Array<string>;
+
+  return sheetCols.filter((col) => col);
+}
+
+/**
+ * Parses the given worksheet to json values. the keys are columns labels.
+ * @param {XLSX.WorkSheet} worksheet
+ * @returns {Array<Record<string, string>>}
+ */
+export function parseSheetToJson(
+  worksheet: XLSX.WorkSheet
+): Array<Record<string, string>> {
+  return XLSX.utils.sheet_to_json(worksheet, {});
+}
+
+/**
+ * Parses the given sheet buffer then retrieves the sheet data and columns.
+ * @param {Buffer} buffer
+ */
+export function parseSheetData(
+  buffer: Buffer
+): [Array<Record<string, string>>, string[]] {
+  const worksheet = parseFirstSheet(buffer);
+
+  const columns = extractSheetColumns(worksheet);
+  const data = parseSheetToJson(worksheet);
+
+  return [data, columns];
+}