Batch add Melonbooks URLs to cart

addMelonCart.js

async function addMelonCart() {
  let list_text = prompt("Enter melonbooks url list (separated by newline)");
  if (!list_text) return;
  urlList = list_text.split("\n");
  // filter empty url
  urlList = urlList.filter((url) => url);
  for (let i = 0; i < urlList.length; i++) {
    const url = urlList[i];
    // check if url is melonbooks
    if (!url.includes("melonbooks.co.jp" && "product_id=")) {
      console.warn(
        `(${i + 1}/${urlList.length}) "${url}" is not a melonbooks url.`
      );
      continue;
    }
    let product_id = url.split("product_id=")[1];
    if (!product_id) {
      console.warn(
        `(${i + 1}/${urlList.length}) "${url}" product_id not found.`
      );
      continue;
    }
    let title = "";
    // Try to get transactionid from item page
    await fetch(
      `https://www.melonbooks.co.jp/detail/detail.php?product_id=${product_id}&adult_view=1`
    )
      .then((response) => response.text())
      .then((html) => {
        // Initialize the DOM parser
        const parser = new DOMParser();
        // Parse the text
        const doc = parser.parseFromString(html, "text/html");
        title = doc.getElementsByTagName("h1")[0].innerText;
        const isInStock =
          doc.getElementsByClassName("tag_cart_main2")?.length > 0;
        if (!isInStock) throw new Error("Out of stock");
        const transactionid = doc
          .querySelector('#cart_anchor > input[name="transactionid"]')
          .getAttribute("value");
        if (!transactionid) throw new Error("Get transaction id failed");
        return transactionid;
      })
      .then((transactionid) => {
        fetch("https://www.melonbooks.co.jp/detail/detail.php?", {
          headers: {
            accept: "*/*",
            "content-type": "application/x-www-form-urlencoded; charset=UTF-8",
          },
          body: `transactionid=${transactionid}&mode=cart_ajax&product_id=${product_id}&product_class_id=&favorite_product_id=&favorite_author_name=&quantity=1`,
          method: "POST",
        })
          .then((response) => response.json())
          .then((data) => {
            console.log(
              `(${i + 1}/${
                urlList.length
              }) Add to cart success: "${title}". Now in cart: ${
                data?.quantity
              }`
            );
          })
          .catch(function (err) {
            console.error(
              `(${i + 1}/${urlList.length}) Add to cart failed: "${title}" `,
              err
            );
          });
      })
      .catch(function (err) {
        console.warn(
          `(${i + 1}/${urlList.length}) Failed to fetch "${title}":`,
          err.message
        );
      });
  }
}
addMelonCart();