fix: pox events should use same index as associated contract log event (#1994)

* fix: pox events should use same index as associated contract log event #1983

* test: add test

Author: zone117x

src/event-stream/event-server.ts

@@ -480,6 +480,8 @@ function parseDataStoreTxEventData(
     return dbTx;
   });
 
+  const poxEventLogs: Map<DbPoxSyntheticEvent, DbSmartContractEvent> = new Map();
+
   for (const event of events) {
     if (!event.committed) {
       logger.debug(`Ignoring uncommitted tx event from tx ${event.txid}`);
@@ -548,6 +550,7 @@ function parseDataStoreTxEventData(
                 ...dbEvent,
                 ...poxEventData,
               };
+              poxEventLogs.set(dbPoxEvent, entry);
               switch (contractName) {
                 case POX_2_CONTRACT_NAME: {
                   dbTx.pox2Events.push(dbPoxEvent);
@@ -723,16 +726,20 @@ function parseDataStoreTxEventData(
       tx.nftEvents,
       tx.stxEvents,
       tx.stxLockEvents,
-      tx.pox2Events,
-      tx.pox3Events,
-      tx.pox4Events,
     ]
       .flat()
       .sort((a, b) => a.event_index - b.event_index);
     tx.tx.event_count = sortedEvents.length;
     for (let i = 0; i < sortedEvents.length; i++) {
       sortedEvents[i].event_index = i;
     }
+    for (const poxEvent of [tx.pox2Events, tx.pox3Events, tx.pox4Events].flat()) {
+      const associatedLogEvent = poxEventLogs.get(poxEvent);
+      if (!associatedLogEvent) {
+        throw new Error(`Missing associated contract log event for pox event ${poxEvent.tx_id}`);
+      }
+      poxEvent.event_index = associatedLogEvent.event_index;
+    }
   }
 
   return dbData;

src/tests/synthetic-stx-txs-tests.ts

@@ -4,6 +4,7 @@ import * as path from 'path';
 import { DecodedTxResult, TxPayloadTypeID } from 'stacks-encoding-native-js';
 import { CoreNodeBlockMessage } from '../event-stream/core-node-message';
 import { parseMessageTransaction } from '../event-stream/reader';
+import { parseNewBlockMessage } from '../event-stream/event-server';
 
 // Test processing of the psuedo-Stacks transactions, i.e. the ones that
 // originate on the Bitcoin chain, and have a `raw_tx == '0x00'.
@@ -194,6 +195,34 @@ describe('synthetic stx txs', () => {
     expect(parsed.parsed_tx).toEqual(expect.objectContaining(expected));
   });
 
+  test('test synthetic tx stx lock 3', () => {
+    const file =
+      'synthetic-tx-payloads/stx_lock-1994-0xd45e090ac442380cf50655e3d1c904c355a501d6dffa3b5e4799083062469dbc.json';
+    const txid = file.split('-').slice(-1)[0].split('.')[0];
+    const payloadStr = fs.readFileSync(path.join(__dirname, file), { encoding: 'utf8' });
+    const blockMsg = JSON.parse(payloadStr) as CoreNodeBlockMessage;
+    const txMsg = blockMsg.transactions.find(t => t.txid === txid);
+    if (!txMsg) {
+      throw new Error(`Cound not find tx ${txid}`);
+    }
+    const parsed = parseNewBlockMessage(ChainID.Mainnet, blockMsg);
+    if (!parsed) {
+      throw new Error(`Failed to parse ${txid}`);
+    }
+    // Ensure real contract event indexes are contiguous
+    const events = [parsed.txs[0].contractLogEvents, parsed.txs[0].stxLockEvents]
+      .flat()
+      .sort((a, b) => a.event_index - b.event_index);
+    expect(events).toHaveLength(13);
+    for (let i = 0; i < events.length; i++) {
+      expect(events[i].event_index).toEqual(i);
+    }
+    // Ensure synthetic pox event indexes are in expected range
+    for (const poxEvent of parsed.txs[0].pox4Events) {
+      expect(poxEvent.event_index).toBeLessThan(events.length);
+    }
+  });
+
   test('test synthetic tx stx lock 2', () => {
     // Testing a newer tx from mainnet (at block 51451)
     const file =