fixes

pkg/cart/cart_item_json_test.go

@@ -0,0 +1,94 @@
+package cart
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+func TestCartItem_FlattensDynamicKeys(t *testing.T) {
+	item := CartItem{
+		Id:       7,
+		Sku:      "YD10050921H11406",
+		Quantity: 2,
+		Extra: map[string]json.RawMessage{
+			"glas":         json.RawMessage(`"V"`),
+			"hangning":     json.RawMessage(`"H"`),
+			"deliveryWeek": json.RawMessage(`10`),
+		},
+	}
+
+	b, err := json.Marshal(&item)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+
+	var flat map[string]json.RawMessage
+	if err := json.Unmarshal(b, &flat); err != nil {
+		t.Fatalf("unmarshal to map: %v", err)
+	}
+
+	// Typed field present at top level.
+	if _, ok := flat["sku"]; !ok {
+		t.Error("expected typed key \"sku\" at top level")
+	}
+	// Dynamic keys flattened to top level (not nested under \"extra\").
+	for _, k := range []string{"glas", "hangning", "deliveryWeek"} {
+		if _, ok := flat[k]; !ok {
+			t.Errorf("expected dynamic key %q flattened to top level", k)
+		}
+	}
+	if string(flat["glas"]) != `"V"` {
+		t.Errorf("glas = %s, want \"V\"", flat["glas"])
+	}
+}
+
+func TestCartItem_RoundTrip(t *testing.T) {
+	original := CartItem{
+		Id:       3,
+		Sku:      "ABC",
+		Quantity: 1,
+		Extra: map[string]json.RawMessage{
+			"color":  json.RawMessage(`"red"`),
+			"weight": json.RawMessage(`12.5`),
+		},
+	}
+
+	b, err := json.Marshal(&original)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+
+	var got CartItem
+	if err := json.Unmarshal(b, &got); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+
+	if got.Sku != original.Sku || got.Id != original.Id || got.Quantity != original.Quantity {
+		t.Errorf("typed fields not preserved: got %+v", got)
+	}
+	if len(got.Extra) != 2 {
+		t.Fatalf("Extra len = %d, want 2 (%v)", len(got.Extra), got.Extra)
+	}
+	if string(got.Extra["color"]) != `"red"` {
+		t.Errorf("color = %s, want \"red\"", got.Extra["color"])
+	}
+	// A typed key must never leak into Extra.
+	if _, leaked := got.Extra["sku"]; leaked {
+		t.Error("typed key \"sku\" leaked into Extra")
+	}
+}
+
+func TestCartItem_NoExtraIsCompact(t *testing.T) {
+	item := CartItem{Id: 1, Sku: "X", Quantity: 1}
+	b, err := json.Marshal(&item)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	var flat map[string]json.RawMessage
+	if err := json.Unmarshal(b, &flat); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+	if _, ok := flat["sku"]; !ok {
+		t.Error("expected \"sku\" in output")
+	}
+}