Firestore

Emulating Firestore locally

exports.calculateCart = functions.firestore.document("carts/{cartId}/items/{itemId}")
  .onWrite(async (change, context) => {
    const cart = db.collection("cards").doc(context.params.cartId);
    const itemPrice = change.after.exists ? change.after.data().price : 0;
    
    console.log(`Ìtem added with price ${itemPrice}, recalculating.`);
    
    await db.runTransaction(async (transaction) => {
        const cartSnap = await transaction.get(cart);
        
        const currentPrice = cartSnap.get("price") || 0;
        const currentCount = cartSnap.get("count") || 0;
        
        return transaction.set(cart, {
            price: currentPrice + itemPrice,
            count: currentCount + 1
        }, { merge: true })
    })  
  })

firebase emulators:start

const functions = require('firebase-functions');
const admin = require('firebase-admin');
const db = admin.initializeApp().firestore();

function updateRestaurantinfo(restaurantId, ratingAdded) {

}
const updateRating = functions.firestore
  .document('/restaurants/{restaurantId}/ratings/{ratingId}')
  .onCreate((snapshot, context) => {
    const restaurantId = context.params.restaurantId;
    const ratingAdded = snapshot.data().rating;

    return updateRestaurantInfo(restaurantId, ratingAdded);
  });

exports.updateRating = updateRating;