Block empty purchases

api/purchase.go

@@ -39,6 +39,11 @@ func (a *api) AddPurchase(num int, w http.ResponseWriter, req *http.Request) {
 		total += product.Price * p.Ammount
 		purchase[i].Price = product.Price
 	}
+	if total == 0 {
+		log.Printf("Empty purchase (%d)", num)
+		w.WriteHeader(http.StatusNotAcceptable)
+		return
+	}
 
 	httpStatus := a.substractMemberBalance(num, total)
 	if httpStatus != http.StatusOK {

src/ShowTransaction.js

@@ -14,6 +14,8 @@ function ShowTransaction() {
         case "purchase":
             show_list = <ShowPurchase purchase={transaction.purchase} />;
             break;
+        default:
+            show_list = null;
     }
 
     return (

src/purchase/Purchase.js

@@ -93,9 +93,9 @@ class Purchase extends React.Component {
             })
             .catch(error => {
                 if (error.name === "not-money") {
-                    this.setState({isLoading: false, error: null, noMoney: true});
+                    this.setState({isLoading: false, noMoney: true});
                 } else {
-                    this.setState({isLoading: false, error: error})
+                    this.setState({isLoading: false, error: error.message})
                 }
             });
     }
@@ -106,7 +106,7 @@ class Purchase extends React.Component {
         }
 
         let alert;
-        if (this.state.noMoney != null) {
+        if (this.state.noMoney) {
             alert = (
                 <Alert variant="warning">
                    No tienes suficiente dinero para realizar esta compra.