add test

test/order_test.go

@@ -15,3 +15,11 @@ func TestUnifiedOrder(t *testing.T) {
 	}
 	fmt.Println(res)
 }
+
+func TestRefund(t *testing.T) {
+	res, err := pay_service.Refund("测试退款", "qfdyD0vJRHP2xJeoaerSWrGMXDacd5wo")
+	if err != nil {
+		t.Error(err)
+	}
+	fmt.Printf("%+v", res)
+}