shoppingCartState.js

// shopping cart state
export default {
    data: {
      cart: [
      ]
    },
    add (product) {
      var found = _.find(this.data.cart, ['id', product.id])
      if(typeof found != 'object') {
        this.data.cart.push({
          id: product.id,
          title: product.title,
          price: product.price,
          image: product.image,
          qty: 1
        })
      }
    },
    inc (product) {
      var found = _.find(this.data.cart, ['id', product.id])
      if(typeof found == 'object') {
        var index = _.indexOf(this.data.cart, found)
        this.data.cart[index].qty++
      }
    },
    dec (product) {
      var found = _.find(this.data.cart, ['id', product.id])
      if(typeof found == 'object') {
        var index = _.indexOf(this.data.cart, found)
  
        if(this.data.cart[index].qty == 1) {
          this.data.cart.splice(index, 1)
        } else {
          this.data.cart[index].qty--
        }
      }
    }
   }