promotions

pkg/promotions/evaluate_test.go

@@ -0,0 +1,42 @@
+package promotions
+
+import "testing"
+
+// TestEvaluatePartialCart exercises the stateless evaluation path used by
+// POST /promotions/evaluate: items drive the total, qualifying effects apply,
+// and near-miss rules surface as pending nudges.
+func TestEvaluatePartialCart(t *testing.T) {
+	svc := NewPromotionService(nil)
+	rules := []PromotionRule{volymrabattRule()}
+	now := timeZero()
+
+	t.Run("items qualify for a tier", func(t *testing.T) {
+		// 2 × 25 000 kr (incl. VAT) = 50 000 kr -> 9% tier.
+		resp := svc.Evaluate(rules, EvaluateRequest{
+			Now: &now,
+			Items: []EvalItem{
+				{Sku: "A", Quantity: 2, PriceIncVat: 2500000},
+			},
+		})
+		if resp.TotalDiscount.IncVat != 450000 {
+			t.Errorf("discount = %d, want 450000", resp.TotalDiscount.IncVat)
+		}
+		if len(resp.AppliedPromotions) != 1 || resp.AppliedPromotions[0].Pending {
+			t.Fatalf("want 1 applied (non-pending) effect, got %+v", resp.AppliedPromotions)
+		}
+	})
+
+	t.Run("total-only fallback surfaces a pending nudge", func(t *testing.T) {
+		// No items, just a total below the entry tier.
+		resp := svc.Evaluate(rules, EvaluateRequest{Now: &now, CartTotalIncVat: 1500000})
+		if resp.TotalDiscount.IncVat != 0 {
+			t.Errorf("nothing should apply, discount = %d", resp.TotalDiscount.IncVat)
+		}
+		if len(resp.AppliedPromotions) != 1 || !resp.AppliedPromotions[0].Pending {
+			t.Fatalf("want 1 pending nudge, got %+v", resp.AppliedPromotions)
+		}
+		if got := resp.AppliedPromotions[0].Progress["remaining"]; got != int64(500000) {
+			t.Errorf("remaining = %v, want 500000", got)
+		}
+	})
+}