feat(sdk-coin-trx): increase default transaction expiration to 3 hours

Change TRANSACTION_DEFAULT_EXPIRATION from 1 hour (3600000ms) to 3 hours
(10800000ms) for all TRX transaction types including token transfers.
Add test to verify token transfers use the 3-hour default expiration.

TICKET: COIN-7612

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Vijay-Jagannathan

modules/sdk-coin-trx/src/lib/utils.ts

@@ -28,7 +28,7 @@ import { AbiCoder, hexConcat } from 'ethers/lib/utils';
 import { DELEGATION_TYPE_URL } from './constants';
 
 export const TRANSACTION_MAX_EXPIRATION = 86400000; // one day
-export const TRANSACTION_DEFAULT_EXPIRATION = 3600000; // one hour
+export const TRANSACTION_DEFAULT_EXPIRATION = 10800000; // three hours
 const ADDRESS_PREFIX_REGEX = /^(41)/;
 const ADDRESS_PREFIX = '41';
 

modules/sdk-coin-trx/test/unit/transactionBuilder/tokenTransferBuilder.ts

@@ -2,6 +2,7 @@ import assert from 'node:assert';
 import { describe, it } from 'node:test';
 import { getBuilder } from '../../../src/lib/builder';
 import { WrappedBuilder } from '../../../src';
+import { TRANSACTION_DEFAULT_EXPIRATION } from '../../../src/lib/utils';
 import {
   PARTICIPANTS,
   BLOCK_HASH,
@@ -36,6 +37,23 @@ describe('TRX Token Transfer Builder', () => {
         assert.deepStrictEqual(rawData.contract, TOKEN_TX_CONTRACT);
       });
 
+      it('a token transfer transaction should have a default expiration of 3 hours', async () => {
+        const before = Date.now();
+        const txBuilder = initTxBuilder();
+        txBuilder.tokenTransferData(TOKEN_TRANSFER_RECIPIENT, '1000000000').sign({ key: PARTICIPANTS.custodian.pk });
+        const tx = await txBuilder.build();
+        const after = Date.now();
+        const txJson = tx.toJson();
+        const expiration = txJson.raw_data.expiration;
+
+        assert.equal(TRANSACTION_DEFAULT_EXPIRATION, 10800000, 'TRANSACTION_DEFAULT_EXPIRATION should be 3 hours');
+        // The default expiration should be ~3 hours (10800000ms) from when the tx was built
+        assert.ok(
+          expiration >= before + TRANSACTION_DEFAULT_EXPIRATION && expiration <= after + TRANSACTION_DEFAULT_EXPIRATION,
+          `Expiration ${expiration} should be approximately 3 hours from now`
+        );
+      });
+
       it('from a signed token contract call transaction', async () => {
         const txHex =
           '{"raw_data":{"contractType":2,"contract":[{"parameter":{"value":{"data":"a9059cbb0000000000000000000000008483618ca85c35a9b923d98bebca718f5a1db2790000000000000000000000000000000000000000000000000000000005f5e100","owner_address":"41c51fbeea78910b15b1d3e8a9b62914ca94d1a4ac","contract_address":"4142a1e39aefa49290f2b3f9ed688d7cecf86cd6e0"},"type_url":"type.googleapis.com/protocol.TriggerSmartContract"},"type":"TriggerSmartContract"}],"expiration":1674581767432,"timestamp":1674578167432,"ref_block_bytes":"578b","ref_block_hash":"6113bb9ac351432b","fee_limit":15000000},"raw_data_hex":"0a02578b22086113bb9ac351432b4088eae7a6de305aae01081f12a9010a31747970652e676f6f676c65617069732e636f6d2f70726f746f636f6c2e54726967676572536d617274436f6e747261637412740a1541c51fbeea78910b15b1d3e8a9b62914ca94d1a4ac12154142a1e39aefa49290f2b3f9ed688d7cecf86cd6e02244a9059cbb0000000000000000000000008483618ca85c35a9b923d98bebca718f5a1db2790000000000000000000000000000000000000000000000000000000005f5e10070888d8ca5de309001c0c39307","txID":"fe21c49f4febd9089125e3a006943c145721d8fcb7ab84136f8c6663ff92f8ed","signature":["0775cde302689eb8293883c66a89b31e80d608bfc3ad3c283b64a490ea4cc712c55a2fd2e62c75843dd7e77d8c4cb52e0f371fbb29b332c259f8cb63c2e6195301"]}';