refactor: always renegotiate overpaid chain swaps

lib/db/repositories/StatsRepository.ts

@@ -58,6 +58,11 @@ type LockedFunds = {
 };
 
 class StatsRepository {
+  private static readonly expirationFailureReasons = [
+    'invoice expired',
+    'swap expired',
+  ];
+
   private static readonly queryVolume =
     // language=PostgreSQL
     `
@@ -196,7 +201,7 @@ WITH data AS (
         'swap' AS type,
         CASE
             WHEN status = ? THEN 'success'
-            WHEN status = ? THEN 'failure'
+            WHEN status = ? AND "failureReason" NOT IN (?) THEN 'failure'
             ELSE 'timeout'
         END AS status
     FROM swaps
@@ -390,7 +395,7 @@ GROUP BY pair, type;
           SwapUpdateEvent.InvoiceFailedToPay,
           SwapUpdateEvent.TransactionRefunded,
         ],
-        ['invoice expired', 'swap expired'],
+        StatsRepository.expirationFailureReasons,
         referral,
         referral,
         minYear,
@@ -406,6 +411,7 @@ GROUP BY pair, type;
       values: [
         SwapUpdateEvent.TransactionClaimed,
         SwapUpdateEvent.InvoiceFailedToPay,
+        StatsRepository.expirationFailureReasons,
         SwapUpdateEvent.InvoiceSettled,
         [
           SwapUpdateEvent.TransactionFailed,

lib/swap/EthereumNursery.ts

@@ -229,6 +229,7 @@ class EthereumNursery extends TypedEventEmitter<{
 
       if (
         this.overpaymentProtector.isUnacceptableOverpay(
+          swap.type,
           expectedAmount,
           actualAmountSat,
         )
@@ -349,6 +350,7 @@ class EthereumNursery extends TypedEventEmitter<{
 
       if (
         this.overpaymentProtector.isUnacceptableOverpay(
+          swap.type,
           expectedAmount,
           actualAmount,
         )

lib/swap/OverpaymentProtector.ts

@@ -1,5 +1,6 @@
 import { OverPaymentConfig } from '../Config';
 import Logger from '../Logger';
+import { SwapType } from '../consts/Enums';
 
 class OverpaymentProtector {
   private static readonly defaultConfig = {
@@ -25,12 +26,24 @@ class OverpaymentProtector {
     );
   }
 
-  public isUnacceptableOverpay = (expected: number, actual: number): boolean =>
-    actual - expected >
-    Math.max(
-      this.overPaymentExemptAmount,
-      actual * this.overPaymentMaxPercentage,
-    );
+  public isUnacceptableOverpay = (
+    type: SwapType,
+    expected: number,
+    actual: number,
+  ): boolean => {
+    // For chain swaps we renegotiate overpayments
+    if (type === SwapType.Chain) {
+      return actual > expected;
+    } else {
+      return (
+        actual - expected >
+        Math.max(
+          this.overPaymentExemptAmount,
+          actual * this.overPaymentMaxPercentage,
+        )
+      );
+    }
+  };
 }
 
 export default OverpaymentProtector;

lib/swap/UtxoNursery.ts

@@ -178,6 +178,7 @@ class UtxoNursery extends TypedEventEmitter<{
 
     if (
       this.overpaymentProtector.isUnacceptableOverpay(
+        swap.type,
         swap.receivingData.expectedAmount,
         outputValue,
       )
@@ -770,6 +771,7 @@ class UtxoNursery extends TypedEventEmitter<{
 
       if (
         this.overpaymentProtector.isUnacceptableOverpay(
+          swap.type,
           updatedSwap.expectedAmount,
           outputValue,
         )

test/unit/swap/OverpaymentProtector.spec.ts

@@ -1,5 +1,6 @@
 import { OverPaymentConfig } from '../../../lib/Config';
 import Logger from '../../../lib/Logger';
+import { SwapType } from '../../../lib/consts/Enums';
 import OverpaymentProtector from '../../../lib/swap/OverpaymentProtector';
 
 describe('OverpaymentProtector', () => {
@@ -68,7 +69,7 @@ describe('OverpaymentProtector', () => {
           new OverpaymentProtector(
             Logger.disabledLogger,
             config,
-          ).isUnacceptableOverpay(expected, actual),
+          ).isUnacceptableOverpay(SwapType.Submarine, expected, actual),
         ).toEqual(false);
       },
     );
@@ -85,7 +86,7 @@ describe('OverpaymentProtector', () => {
           new OverpaymentProtector(
             Logger.disabledLogger,
             config,
-          ).isUnacceptableOverpay(expected, actual),
+          ).isUnacceptableOverpay(SwapType.Submarine, expected, actual),
         ).toEqual(false);
       },
     );
@@ -102,9 +103,28 @@ describe('OverpaymentProtector', () => {
           new OverpaymentProtector(
             Logger.disabledLogger,
             config,
-          ).isUnacceptableOverpay(expected, actual),
+          ).isUnacceptableOverpay(SwapType.Submarine, expected, actual),
         ).toEqual(true);
       },
     );
+
+    test.each`
+      expected | actual | expectedResult
+      ${100}   | ${101} | ${true}
+      ${100}   | ${105} | ${true}
+      ${100}   | ${110} | ${true}
+      ${100}   | ${100} | ${false}
+    `(
+      'should not allow overpayment for chain swaps',
+      ({ expected, actual, expectedResult }) => {
+        expect(
+          new OverpaymentProtector(Logger.disabledLogger).isUnacceptableOverpay(
+            SwapType.Chain,
+            expected,
+            actual,
+          ),
+        ).toEqual(expectedResult);
+      },
+    );
   });
 });