backendFile.js

//stripe.jsw

import {fetch} from 'wix-fetch';

export async function subscription(token, item) {
  const cart = item;
  const apiKey = "SECRET_API_KEY";
  const response = await fetch("https://api.stripe.com/v1/subscriptions", {
  method: 'post',
  headers: {
    "Content-Type": "application/x-www-form-urlencoded",
    "Authorization": "Bearer " + apiKey
  },
  body: encodeBody(token, cart)
  });
  if (response.status >= 200 && response.status < 300) {
  // transaction successful - get charge ID
    const ret = await response.json();
    return {"chargeId": ret.id};
}
// transaction failed - return error messages and codes
  let res = await response.json();
  let err = res.error.message;
  let code = res.error.code;
  let type = res.error.type;
  return {"error": err, "code": code, "type": type};
}

function encodeBody(token, cart) {
  let encoded = "";
  for (let [k, v] of Object.entries(cart)) {
    encoded = encoded.concat(k,"=", encodeURI(v), "&");
  }
    encoded = encoded.concat("source=", encodeURI(token));
  return encoded;
}

//Creating a customer 

export async function createCustomer(customer) {
  const client = String(customer);
  const apiKey = "SECRET_API_KEY";
  const response = await fetch("https://api.stripe.com/v1/customers", {
  method: 'post',
  headers: {
    "Content-Type": "application/x-www-form-urlencoded",
    "Authorization": "Bearer " + apiKey
  },
  body: encodeClient(client)
  });
  if (response.status >= 200 && response.status < 300) {
  const json = await response.json();
  return json.id;
  }
  const responseText = await response.text();
  return response.status;
}

function encodeClient(client){
  let encoded = "";
  encoded = encoded.concat("email=", encodeURI(client));
  return encoded;
}