Fixing bug where items were allowed to be deleted when referenced by a character

services/front/design/design.go

@@ -69,11 +69,13 @@ var _ = Service("front", func() {
 		Payload(String)
 		Result(Empty)
 		Error("NotFound")
+		Error("BadRequest")
 
 		HTTP(func() {
 			DELETE("/item/{name}")
 			Response(StatusOK)
 			Response("NotFound", StatusNotFound)
+			Response("BadRequest", StatusBadRequest)
 		})
 	})
 

services/front/front.go

@@ -10,6 +10,7 @@ import (
 	genItemClient "crossnokaye-interview-assignment/services/item/gen/grpc/item/client"
 	genItem "crossnokaye-interview-assignment/services/item/gen/item"
 	"errors"
+	"fmt"
 	"github.com/golang/protobuf/ptypes/empty"
 	goa "goa.design/goa/v3/pkg"
 	"google.golang.org/grpc"
@@ -33,9 +34,11 @@ type characterClient struct {
 }
 
 type inventoryClient struct {
-	addItem            goa.Endpoint
-	removeItem         goa.Endpoint
-	listInventoryItems goa.Endpoint
+	addItem                goa.Endpoint
+	removeItem             goa.Endpoint
+	removeAll              goa.Endpoint
+	listInventoryItems     goa.Endpoint
+	listCharactersWithItem goa.Endpoint
 }
 
 // front service example implementation.
@@ -71,7 +74,9 @@ func NewFront(logger *log.Logger, itemClientConnection *grpc.ClientConn, charact
 		inventoryClient: &inventoryClient{
 			icc.AddItem(),
 			icc.RemoveItem(),
+			icc.RemoveAll(),
 			icc.ListInventory(),
+			icc.ListCharactersWithItem(),
 		}}
 }
 
@@ -130,6 +135,18 @@ func (s *frontsrvc) UpdateItem(ctx context.Context, p *front.Item) (res *front.I
 // DeleteItem implements deleteItem.
 func (s *frontsrvc) DeleteItem(ctx context.Context, p string) (err error) {
 	s.logger.Print("front.deleteItem")
+
+	characterResponse, err := s.inventoryClient.listCharactersWithItem(ctx, &genInventory.ListCharactersWithItemPayload{ItemName: &p})
+	if err != nil {
+		return err
+	}
+
+	characters := characterResponse.([]string)
+
+	if len(characters) > 0 {
+		return front.MakeBadRequest(fmt.Errorf("item '%s' is referenced by character(s) %v", p, characters))
+	}
+
 	_, err = s.itemClient.deleteItem(ctx, &genItem.DeleteItemPayload{Name: &p})
 	if err != nil {
 		return err
@@ -200,6 +217,11 @@ func (s *frontsrvc) DeleteCharacter(ctx context.Context, name string) (err error
 		return err
 	}
 
+	_, err = s.inventoryClient.removeAll(ctx, &genInventory.RemoveAllPayload{CharacterName: &name})
+	if err != nil {
+		return err
+	}
+
 	return
 }
 
@@ -245,7 +267,7 @@ func (s *frontsrvc) ListInventoryItems(ctx context.Context, payload *front.ListI
 	}
 
 	itemNames := listInventoryResponse.([]string)
-	if itemNames == nil {
+	if len(itemNames) == 0 {
 		return
 	}
 	itemResponse, err := s.itemClient.listItems(ctx, &genItem.ListItemsPayload{NameFilter: itemNames})