diff --git a/modules/ecash-agora/src/agora.ts b/modules/ecash-agora/src/agora.ts
--- a/modules/ecash-agora/src/agora.ts
+++ b/modules/ecash-agora/src/agora.ts
@@ -140,9 +140,12 @@
dustAmount?: number;
/** Fee per kB to use when building the tx. */
feePerKb?: number;
+ /** Allow accepting an offer such that the remaining quantity is unacceptable */
+ allowUnspendable?: boolean;
}): Tx {
const dustAmount = params.dustAmount ?? DEFAULT_DUST_LIMIT;
const feePerKb = params.feePerKb ?? DEFAULT_FEE_PER_KB;
+ const allowUnspendable = params.allowUnspendable ?? false;
const txBuild = this._acceptTxBuilder({
covenantSk: params.covenantSk,
covenantPk: params.covenantPk,
@@ -155,6 +158,7 @@
params.recipientScript,
],
acceptedTokens: params.acceptedTokens,
+ allowUnspendable,
});
return txBuild.sign(params.ecc, feePerKb, dustAmount);
}
@@ -197,6 +201,7 @@
fuelInputs: TxBuilderInput[];
extraOutputs: TxBuilderOutput[];
acceptedTokens?: bigint;
+ allowUnspendable?: boolean;
}): TxBuilder {
switch (this.variant.type) {
case 'ONESHOT':
@@ -232,6 +237,48 @@
`Must acceptedTokens must be a multiple of ${truncFactor}`,
);
}
+ // Validation to avoid creating an unspendable offer
+ //
+ // 1 - confirm the remaining offer amount is more than the
+ // min accept amount for this agora partial
+ //
+ // 2 - Confirm the cost of accepting the (full) remainder is
+ // at least dust. This is already confirmed...for offers
+ // created by this lib... as minAcceptedTokens() must
+ // cost more than dust
+ //
+ //
+ // If these condtions are not met, an AgoraOffer would be created
+ // that is impossible to accept; can only be canceld by its maker
+
+ // Get the token qty that would remain after this accept
+ const offeredTokens = BigInt(this.token.amount);
+ if (
+ typeof params.allowUnspendable !== 'undefined' &&
+ params.allowUnspendable === false
+ ) {
+ const remainingTokens =
+ offeredTokens - params.acceptedTokens;
+ if (remainingTokens > 0n) {
+ // Full accepts are always ok
+
+ const minAcceptedTokens =
+ agoraPartial.minAcceptedTokens();
+ const priceOfRemainingTokens =
+ agoraPartial.askedSats(remainingTokens);
+ if (remainingTokens < minAcceptedTokens) {
+ throw new Error(
+ `Accepting ${params.acceptedTokens} token satoshis would leave an amount lower than the min acceptable by the terms of this contract, and hence unacceptable. Accept fewer tokens or the full offer.`,
+ );
+ }
+ if (priceOfRemainingTokens < agoraPartial.dustAmount) {
+ throw new Error(
+ `Accepting ${params.acceptedTokens} token satoshis would leave an amount priced lower than dust. Accept fewer tokens or the full offer.`,
+ );
+ }
+ }
+ }
+
txBuild.inputs.push({
input: this.txBuilderInput,
signatory: AgoraPartialSignatory(
@@ -243,7 +290,7 @@
});
txBuild.inputs.push(...params.fuelInputs);
const sendAmounts: Amount[] = [0];
- const offeredTokens = BigInt(this.token.amount);
+
if (offeredTokens > params.acceptedTokens) {
sendAmounts.push(offeredTokens - params.acceptedTokens);
}
diff --git a/modules/ecash-agora/tests/partial-helper-alp.ts b/modules/ecash-agora/tests/partial-helper-alp.ts
--- a/modules/ecash-agora/tests/partial-helper-alp.ts
+++ b/modules/ecash-agora/tests/partial-helper-alp.ts
@@ -132,6 +132,7 @@
takerSk: Uint8Array;
takerInput: TxBuilderInput;
acceptedTokens: bigint;
+ allowUnspendable?: boolean;
}) {
const takerSk = params.takerSk;
const takerPk = params.ecc.derivePubkey(takerSk);
@@ -144,6 +145,7 @@
fuelInputs: [params.takerInput],
recipientScript: takerP2pkh,
acceptedTokens: params.acceptedTokens,
+ allowUnspendable: params.allowUnspendable,
});
const acceptTxid = (await params.chronik.broadcastTx(acceptTx.ser())).txid;
return acceptTxid;
diff --git a/modules/ecash-agora/tests/partial-helper-slp.ts b/modules/ecash-agora/tests/partial-helper-slp.ts
--- a/modules/ecash-agora/tests/partial-helper-slp.ts
+++ b/modules/ecash-agora/tests/partial-helper-slp.ts
@@ -136,6 +136,7 @@
takerSk: Uint8Array;
takerInput: TxBuilderInput;
acceptedTokens: bigint;
+ allowUnspendable?: boolean;
}) {
const takerSk = params.takerSk;
const takerPk = params.ecc.derivePubkey(takerSk);
@@ -148,6 +149,7 @@
fuelInputs: [params.takerInput],
recipientScript: takerP2pkh,
acceptedTokens: params.acceptedTokens,
+ allowUnspendable: params.allowUnspendable,
});
const acceptTxid = (await params.chronik.broadcastTx(acceptTx.ser())).txid;
return acceptTxid;
diff --git a/modules/ecash-agora/tests/partial.alp.test.ts b/modules/ecash-agora/tests/partial.alp.test.ts
--- a/modules/ecash-agora/tests/partial.alp.test.ts
+++ b/modules/ecash-agora/tests/partial.alp.test.ts
@@ -2,7 +2,7 @@
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-import { expect, use } from 'chai';
+import { expect, use, assert } from 'chai';
import chaiAsPromised from 'chai-as-promised';
import { ChronikClient } from 'chronik-client';
import {
@@ -103,6 +103,7 @@
priceNanoSatsPerToken: bigint;
acceptedTokens: bigint;
askedSats: number;
+ allowUnspendable?: boolean;
}
const TEST_CASES: TestCase[] = [
{
@@ -118,6 +119,7 @@
priceNanoSatsPerToken: 1000000000n,
acceptedTokens: 546n,
askedSats: 546,
+ allowUnspendable: true,
},
{
offeredTokens: 1000n,
@@ -405,6 +407,7 @@
priceNanoSatsPerToken: 1000n,
acceptedTokens: 0x1e000000n,
askedSats: 549,
+ allowUnspendable: true,
},
{
offeredTokens: 0xffffffffffffn,
@@ -467,7 +470,24 @@
offer,
takerInput,
acceptedTokens: testCase.acceptedTokens,
+ allowUnspendable: testCase.allowUnspendable,
});
+ if (testCase.allowUnspendable) {
+ // We get an error for test cases that would result in unspendable amounts
+ // if we do not pass allowUnspendable to agoraOffer.acceptTx
+ await assert.isRejected(
+ takeAlpOffer({
+ chronik,
+ ecc,
+ takerSk,
+ offer,
+ takerInput,
+ acceptedTokens: testCase.acceptedTokens,
+ allowUnspendable: false,
+ }),
+ `Accepting ${testCase.acceptedTokens} token satoshis would leave an amount lower than the min acceptable by the terms of this contract, and hence unacceptable. Accept fewer tokens or the full offer.`,
+ );
+ }
const acceptTx = await chronik.tx(acceptTxid);
const offeredTokens = agoraPartial.offeredTokens();
if (testCase.acceptedTokens == offeredTokens) {
diff --git a/modules/ecash-agora/tests/partial.slp.test.ts b/modules/ecash-agora/tests/partial.slp.test.ts
--- a/modules/ecash-agora/tests/partial.slp.test.ts
+++ b/modules/ecash-agora/tests/partial.slp.test.ts
@@ -2,7 +2,7 @@
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-import { expect, use } from 'chai';
+import { expect, use, assert } from 'chai';
import chaiAsPromised from 'chai-as-promised';
import { ChronikClient } from 'chronik-client';
import {
@@ -102,6 +102,7 @@
priceNanoSatsPerToken: bigint;
acceptedTokens: bigint;
askedSats: number;
+ allowUnspendable?: boolean;
}
const TEST_CASES: TestCase[] = [
{
@@ -117,6 +118,7 @@
priceNanoSatsPerToken: 1000000000n,
acceptedTokens: 546n,
askedSats: 546,
+ allowUnspendable: true,
},
{
offeredTokens: 1000n,
@@ -194,6 +196,7 @@
priceNanoSatsPerToken: 1000000000n,
acceptedTokens: 546n,
askedSats: 546,
+ allowUnspendable: true,
},
{
offeredTokens: 1000000n,
@@ -522,7 +525,24 @@
offer,
takerInput,
acceptedTokens: testCase.acceptedTokens,
+ allowUnspendable: testCase.allowUnspendable,
});
+ if (testCase.allowUnspendable) {
+ // We get an error for test cases that would result in unspendable amounts
+ // if we do not pass allowUnspendable to agoraOffer.acceptTx
+ await assert.isRejected(
+ takeSlpOffer({
+ chronik,
+ ecc,
+ takerSk,
+ offer,
+ takerInput,
+ acceptedTokens: testCase.acceptedTokens,
+ allowUnspendable: false,
+ }),
+ `Accepting ${testCase.acceptedTokens} token satoshis would leave an amount lower than the min acceptable by the terms of this contract, and hence unacceptable. Accept fewer tokens or the full offer.`,
+ );
+ }
const acceptTx = await chronik.tx(acceptTxid);
const offeredTokens = agoraPartial.offeredTokens();
if (testCase.acceptedTokens == offeredTokens) {