fix: eviction race

yarn-project/p2p/src/mem_pools/tx_pool_v2/eviction/fee_payer_balance_eviction_rule.test.ts

@@ -75,7 +75,9 @@ describe('FeePayerBalanceEvictionRule', () => {
     db = mock<MerkleTreeReadOperations>();
     mockWorldState.getCommitted.mockReturnValue(db);
     mockWorldState.getSnapshot.mockReturnValue(db);
-    mockWorldState.syncImmediate.mockResolvedValue(BlockNumber(1));
+    mockWorldState.syncImmediate.mockImplementation((blockNumber?: number) =>
+      Promise.resolve(BlockNumber(blockNumber ?? 1)),
+    );
 
     feePayerBalances = new Map();
     setupBalances(feePayerBalances);
@@ -312,7 +314,7 @@ describe('FeePayerBalanceEvictionRule', () => {
 
         await rule.evict(context, pool);
 
-        expect(mockWorldState.syncImmediate).toHaveBeenCalledWith(5);
+        expect(mockWorldState.syncImmediate).toHaveBeenCalledWith(5, true);
         expect(mockWorldState.getSnapshot).toHaveBeenCalledWith(5);
       });
 
@@ -337,6 +339,29 @@ describe('FeePayerBalanceEvictionRule', () => {
         expect(result.success).toBe(true);
         expect(result.txsEvicted).toEqual([lowMeta.txHash]);
       });
+
+      it('skips eviction gracefully when block was pruned (reorg race)', async () => {
+        const meta = createMeta('0x1111', { feeLimit: 100n });
+        const txsByFeePayer = new Map([[feePayer1, [meta]]]);
+        const pool = createPoolOps(txsByFeePayer);
+        setupBalances(new Map([[feePayer1, 0n]]));
+
+        // Simulate reorg: syncImmediate returns a block number less than the target
+        mockWorldState.syncImmediate.mockResolvedValue(BlockNumber(3));
+
+        const context: EvictionContext = {
+          event: EvictionEvent.BLOCK_MINED,
+          block: blockHeader, // block number 5
+          newNullifiers: [],
+          feePayers: [feePayer1],
+        };
+
+        const result = await rule.evict(context, pool);
+
+        expect(result.success).toBe(true);
+        expect(result.txsEvicted).toHaveLength(0);
+        expect(mockWorldState.getSnapshot).not.toHaveBeenCalled();
+      });
     });
 
     describe('CHAIN_PRUNED events', () => {
@@ -368,6 +393,32 @@ describe('FeePayerBalanceEvictionRule', () => {
         expect(mockWorldState.getSnapshot).toHaveBeenCalledWith(BlockNumber(3));
       });
 
+      it('reports failure when snapshot data is unavailable', async () => {
+        const meta = createMeta('0x1111', { feeLimit: 100n });
+        const txsByFeePayer = new Map([[feePayer1, [meta]]]);
+        const pool = createPoolOps(txsByFeePayer);
+
+        // Balance insufficient - would trigger eviction if snapshot were available
+        setupBalances(new Map([[feePayer1, 0n]]));
+
+        // Make getSnapshot return a db that throws (simulating pruned block data)
+        const dbFailing = mock<MerkleTreeReadOperations>();
+        dbFailing.getPreviousValueIndex.mockRejectedValue(new Error('Unable to find low leaf'));
+        mockWorldState.getSnapshot.mockReturnValue(dbFailing);
+
+        const context: EvictionContext = {
+          event: EvictionEvent.CHAIN_PRUNED,
+          blockNumber: BlockNumber(3),
+        };
+
+        const result = await rule.evict(context, pool);
+
+        // Error propagates to outer catch, reported as failure
+        expect(result.success).toBe(false);
+        expect(result.txsEvicted).toHaveLength(0);
+        expect(result.error).toBeDefined();
+      });
+
       it('evicts txs when balance changed after prune', async () => {
         const meta = createMeta('0x1111', { feeLimit: 100n });
         const txsByFeePayer = new Map([[feePayer1, [meta]]]);

yarn-project/p2p/src/mem_pools/tx_pool_v2/eviction/fee_payer_balance_eviction_rule.ts

@@ -29,7 +29,15 @@ export class FeePayerBalanceEvictionRule implements EvictionRule {
 
       if (context.event === EvictionEvent.BLOCK_MINED) {
         const blockNumber = context.block.getBlockNumber();
-        await this.worldState.syncImmediate(blockNumber);
+        const syncedTo = await this.worldState.syncImmediate(blockNumber, true);
+        if (syncedTo < blockNumber) {
+          // Block was likely pruned due to a reorg. Skip eviction;
+          // the subsequent CHAIN_PRUNED event will re-evaluate all pending fee payers.
+          this.log.debug(
+            `Skipping BLOCK_MINED fee payer eviction: world state at block ${syncedTo}, expected ${blockNumber}`,
+          );
+          return { reason: this.reason, success: true, txsEvicted: [] };
+        }
         return await this.evictForFeePayers(context.feePayers, this.worldState.getSnapshot(blockNumber), pool);
       }
 
@@ -45,7 +53,7 @@ export class FeePayerBalanceEvictionRule implements EvictionRule {
         txsEvicted: [],
       };
     } catch (err) {
-      this.log.error('Failed to evict txs due to fee payer balance', { err });
+      this.log.warn('Failed to evict txs due to fee payer balance', { err });
       return {
         reason: this.reason,
         success: false,