Testing simultaneous guest user cart management of CoCart, ensuring each session is separate

cocart-node.js

const axios = require("axios").default
const axiosCookieJarSupport = require("axios-cookiejar-support").default
const CookieJar = require("tough-cookie").CookieJar
const assert = require('assert')
let instanceId = 1
const createAxiosInstance = () => {
    const axiosInstance = axios.create({
        baseURL: "https://test.site/wp-json/cocart/v1",
        withCredentials: true,
    })
    axiosCookieJarSupport(axiosInstance)
    axiosInstance.defaults.jar = new CookieJar()
    axiosInstance.instanceId = instanceId++
    return axiosInstance
}

const getCart = async (axiosInstance) =>
    axiosInstance.get("/get-cart").then((response) => {
        console.log(axiosInstance.instanceId, "get-cart", response.data)
        return response.data
    })

const addItem = async (axiosInstance, productId) =>
    axiosInstance
        .post("/add-item", {
            product_id: productId,
        })
        .then((response) => {
            console.log(axiosInstance.instanceId, "add-item", response.data)
            return response.data
        })

const clearCart = async (axiosInstance) =>
    axiosInstance.post("/clear").then((response) => {
        console.log(axiosInstance.instanceId, "clear", response.data)
        return response.data
    })

async function run(axiosInstance) {
    let cart = await getCart(axiosInstance)
    assert(cart.length == 0)
    await addItem(axiosInstance, 1)
    cart = await getCart(axiosInstance)
    assert(cart.totals.subtotal == '$10.00')
    await addItem(axiosInstance, 2)
    cart = await getCart(axiosInstance)
    assert(cart.totals.subtotal == '$20.00')
}

run(createAxiosInstance())
run(createAxiosInstance())