unique ids

pkg/cart/cart-grain.go

@@ -65,6 +65,7 @@ type CartNotification struct {
 
 type SubscriptionDetails struct {
 	Id           string          `json:"id"`
+	Version      uint16          `json:"version"`
 	OfferingCode string          `json:"offeringCode,omitempty"`
 	SigningType  string          `json:"signingType,omitempty"`
 	Meta         json.RawMessage `json:"data,omitempty"`

pkg/cart/mutation_upsert_subscriptiondetails.go

@@ -24,8 +24,10 @@ func UpsertSubscriptionDetails(g *CartGrain, m *messages.UpsertSubscriptionDetai
 		}
 
 		id := MustNewCartId().String()
+
 		g.SubscriptionDetails[id] = &SubscriptionDetails{
 			Id:           id,
+			Version:      1,
 			OfferingCode: m.OfferingCode,
 			SigningType:  m.SigningType,
 			Meta:         meta,
@@ -38,11 +40,14 @@ func UpsertSubscriptionDetails(g *CartGrain, m *messages.UpsertSubscriptionDetai
 	if !ok {
 		return fmt.Errorf("subscription details not found")
 	}
+	changed := false
 	if m.OfferingCode != "" {
 		existing.OfferingCode = m.OfferingCode
+		changed = true
 	}
 	if m.SigningType != "" {
 		existing.SigningType = m.SigningType
+		changed = true
 	}
 	if m.Data != nil {
 		// Only validate & assign if there is content; empty -> leave as-is.
@@ -51,7 +56,11 @@ func UpsertSubscriptionDetails(g *CartGrain, m *messages.UpsertSubscriptionDetai
 				return fmt.Errorf("subscription details invalid json")
 			}
 			existing.Meta = m.Data.Value
+			changed = true
 		}
 	}
+	if changed {
+		existing.Version++
+	}
 	return nil
 }