Get Data from nested collection on Firestore

db.js

// Database format: /products/{productId}/prices/{priceId}

export async function getProductPricesById(id) {
  const prices = []
  const snapshot = await DataSource.collection('products')
    .doc(id)
    .collection('prices')
    .get()

  snapshot.forEach((doc) => {
    prices.push({ id: doc.id, data: doc.data() })
  })

  return prices
}

export async function getAllProducts() {
  const products = []
  const snapshot = await DataSource.collection('products')
    .where('active', '==', true)
    .get()

  const productsResolved = await Promise.all(
    snapshot.docs.map(async (doc) => {
      const product = {}
      product.id = doc.id
      product.data = doc.data()

      const productPrices = await getProductPricesById(product.id)
      product.prices = productPrices
      products.push(product)
      return products
    })
  )

  return productsResolved.length > 0
    ? productsResolved[productsResolved.length - 1]
    : []
}