async listenForCart()

in codelab-initial-state/public/js/homepage.js [98:131]

• 23 lines of code
• 4 McCabe index (conditional complexity)

  async listenForCart(uid) {
    console.log(`listenForCart(${uid})`);

    // If we were previously listening to the cart for
    // a different user, unsubscribe.
    if (this.cartItemsUnsub) {
      this.cartItemsUnsub();
      this.cartItemsUnsub = null;
    }

    // If needed, create the base cart object
    const cartRef = this.db.collection("carts").doc(uid);
    await cartRef.set(
      {
        ownerUID: uid
      },
      { merge: true }
    );

    // Listen for updates to the cart
    // TODO: Unsub from this as well
    this.cartUnsub = cartRef.onSnapshot(cart => {
      console.log("cart", cart.data());

      const total = cart.data().totalPrice || 0;
      const count = cart.data().itemCount || 0;
      this.headerBar.setIconText("cart", `\$${total.toFixed(2)} (${count})`);
    });

    // Listen for updates to cart items
    this.cartItemsUnsub = cartRef.collection("items").onSnapshot(items => {
      this.setCartItems(items);
    });
  }