googleSheetsService.js

const { google } = require("googleapis");
const sheets = google.sheets("v4");

const SCOPES = ["https://www.googleapis.com/auth/spreadsheets"];

async function getAuthToken() {
  const auth = new google.auth.GoogleAuth({
    scopes: SCOPES,
  });
  const authToken = await auth.getClient();
  return authToken;
}

async function getSpreadSheet({ spreadsheetId, auth }) {
  const res = await sheets.spreadsheets.get({
    spreadsheetId,
    auth,
  });
  return res;
}

async function getSpreadSheetValues({ spreadsheetId, auth, sheetName }) {
  const res = await sheets.spreadsheets.values.get({
    spreadsheetId,
    auth,
    range: sheetName,
  });
  return res;
}

async function appendSpreadSheetValues({
  spreadsheetId,
  auth,
  sheetName,
  values,
}) {
  const res = await sheets.spreadsheets.values.append({
    spreadsheetId,
    auth,
    range: sheetName,
    resource: {
      values: values,
    },
    valueInputOption: "USER_ENTERED", // USER_ENTERED or RAW
    // insertDataOption: "INSERT_ROWS" or "OVERWRITE"
  });
  return res;
}

module.exports = {
  getAuthToken,
  getSpreadSheet,
  getSpreadSheetValues,
  appendSpreadSheetValues,
};