taler-typescript-core

commit 7bae442956ab603886979ff99a6aff816ed1bc19
parent 2a71a72efcdf609cb73180e6b41e9898ddf2692b
Author: Florian Dold <dold@taler.net>
Date:   Thu,  3 Sep 2026 15:41:17 +0200

wallet-core: refresh what a deposit refund restores on the coin

A full refund credits the coin with the contribution minus the refund
fee plus the waived deposit fee; melting only the contribution
stranded the difference.

Diffstat:
M
packages/taler-wallet-core/src/deposits.test.ts
 | 
26
++++++++++++++++++++++++++
M
packages/taler-wallet-core/src/deposits.ts
 | 
49
+++++++++++++++++++++++++++++++++++++++++++++----

2 files changed, 71 insertions(+), 4 deletions(-)
diff --git a/packages/taler-wallet-core/src/deposits.test.ts b/packages/taler-wallet-core/src/deposits.test.ts
@@ -16,6 +16,7 @@
 
 import {
   AbsoluteTime,
+  Amounts,
   HttpStatusCode,
   TalerErrorCode,
   TalerProtocolTimestamp,
@@ -38,6 +39,7 @@ import {
   depositRefundStatusIsRetryable,
   reconstructDepositRefundRequests,
   testing_getDepositTrackingTiming,
+  getDepositAbortRefreshAmount,
 } from "./deposits.js";
 
 test("deposit tracking waits at a future wire deadline", () => {
@@ -252,3 +254,27 @@ test("hard-KYC deposit cleanup remains finalizing until recovery completes", () 
     },
   );
 });
+
+test("deposit abort refreshes the amount the refund restored on the coin", () => {
+  const denom = { feeDeposit: "TESTKUDOS:0.1", feeRefund: "TESTKUDOS:0.02" };
+  assert.strictEqual(
+    Amounts.stringify(
+      getDepositAbortRefreshAmount(
+        "TESTKUDOS:5",
+        DepositElementStatus.RefundSuccess,
+        denom,
+      ),
+    ),
+    "TESTKUDOS:5.08",
+  );
+  assert.strictEqual(
+    Amounts.stringify(
+      getDepositAbortRefreshAmount(
+        "TESTKUDOS:5",
+        DepositElementStatus.RefundNotFound,
+        denom,
+      ),
+    ),
+    "TESTKUDOS:5",
+  );
+});
diff --git a/packages/taler-wallet-core/src/deposits.ts b/packages/taler-wallet-core/src/deposits.ts
@@ -24,6 +24,7 @@
 import {
   AbsoluteTime,
   AmountJson,
+  AmountLike,
   AmountString,
   Amounts,
   BatchDepositRequestCoin,
@@ -1036,6 +1037,33 @@ function isDepositHardKycFailure(depositGroup: WalletDepositGroup): boolean {
  * already wired the deposit.  Other permanent refund failures prove neither
  * recovery nor delivery and therefore get their own outcome.
  */
+/**
+ * The amount a refresh can claim back from a coin after the deposit abort
+ * refunded it.
+ *
+ * A refund of the full contribution makes the exchange credit the coin with
+ * the contribution minus the refund fee, plus the deposit fee it waives on a
+ * full refund.  A coin whose deposit the exchange never saw still holds its
+ * whole contribution.
+ */
+export function getDepositAbortRefreshAmount(
+  contribution: AmountLike,
+  status:
+    | DepositElementStatus.RefundSuccess
+    | DepositElementStatus.RefundNotFound,
+  denom: { feeDeposit: AmountLike; feeRefund: AmountLike },
+): AmountJson {
+  const contrib = Amounts.parseOrThrow(contribution);
+  if (status === DepositElementStatus.RefundNotFound) {
+    return contrib;
+  }
+  const afterRefundFee = Amounts.sub(contrib, denom.feeRefund);
+  if (afterRefundFee.saturated) {
+    return Amounts.zeroOfAmount(contrib);
+  }
+  return Amounts.add(afterRefundFee.amount, denom.feeDeposit).amount;
+}
+
 export function classifyDepositAbortOutcome(
   statusPerCoin: DepositElementStatus[],
   recovery?: "pending" | "recovered" | "failed",
@@ -1360,17 +1388,30 @@ async function refundDepositGroup(
     if (outcome === "refunding") {
       return;
     }
+    const denoms = await getDenomInfos(wex, tx, coins);
     const refreshCoins: CoinRefreshRequest[] = [];
     for (let i = 0; i < newTxPerCoin.length; i++) {
+      const st = newTxPerCoin[i];
       if (
-        newTxPerCoin[i] !== DepositElementStatus.RefundSuccess &&
-        newTxPerCoin[i] !== DepositElementStatus.RefundNotFound
+        st !== DepositElementStatus.RefundSuccess &&
+        st !== DepositElementStatus.RefundNotFound
       ) {
         continue;
       }
+      const coinPub = payCoinSelection.coinPubs[i];
+      const coin = coinsByPub.get(coinPub);
+      checkDbInvariant(!!coin, `coin ${coinPub} not found in DB`);
+      const denom = denoms.get(denomRefKey(coin));
+      checkDbInvariant(!!denom, `denomination of coin ${coinPub} is missing`);
       refreshCoins.push({
-        amount: payCoinSelection.coinContributions[i],
-        coinPub: payCoinSelection.coinPubs[i],
+        amount: Amounts.stringify(
+          getDepositAbortRefreshAmount(
+            payCoinSelection.coinContributions[i],
+            st,
+            denom,
+          ),
+        ),
+        coinPub,
         refundRequest: refundReqPerCoin[i],
       });
     }