taler-typescript-core

commit 1ba58720d4ef0806107e6043663fc495b57f91e2
parent 6affddc50527a8a4176e334166bff6b63c646ca6
Author: Florian Dold <dold@taler.net>
Date:   Thu, 20 Aug 2026 19:06:45 +0200

wallet-core: price impossible refreshes as full loss

Diffstat:
A
packages/taler-wallet-core/src/refresh.test.ts
 | 
32
++++++++++++++++++++++++++++++++
M
packages/taler-wallet-core/src/refresh.ts
 | 
5
++++-

2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/packages/taler-wallet-core/src/refresh.test.ts b/packages/taler-wallet-core/src/refresh.test.ts
@@ -0,0 +1,32 @@
+/*
+ This file is part of GNU Taler
+ (C) 2026 Taler Systems S.A.
+
+ GNU Taler is free software; you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 3, or (at your option) any later version.
+
+ GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+import { Amounts, DenominationInfo } from "@gnu-taler/taler-util";
+import assert from "node:assert";
+import { test } from "node:test";
+import { getTotalRefreshCostInternal } from "./refresh.js";
+
+test("an impossible refresh costs the full remaining amount", () => {
+  const amountLeft = Amounts.parseOrThrow("TESTKUDOS:4");
+  const refreshedDenom = {
+    value: "TESTKUDOS:5",
+    feeRefresh: "TESTKUDOS:0.1",
+  } as DenominationInfo;
+
+  assert.deepStrictEqual(
+    getTotalRefreshCostInternal([], refreshedDenom, amountLeft),
+    amountLeft,
+  );
+});
diff --git a/packages/taler-wallet-core/src/refresh.ts b/packages/taler-wallet-core/src/refresh.ts
@@ -440,7 +440,7 @@ export async function getTotalRefreshCosts(
  * Considers refresh fees, withdrawal fees after refresh and amounts too small
  * to refresh.
  */
-function getTotalRefreshCostInternal(
+export function getTotalRefreshCostInternal(
   denoms: WalletDenomination[],
   refreshedDenom: DenominationInfo,
   amountLeft: AmountJson,
@@ -450,6 +450,9 @@ function getTotalRefreshCostInternal(
       refreshedDenom.value
     }, amount left ${Amounts.stringify(amountLeft)}`,
   );
+  if (denoms.length === 0) {
+    return Amounts.copy(amountLeft);
+  }
   const withdrawAmount = Amounts.sub(
     amountLeft,
     refreshedDenom.feeRefresh,