test: add functional test for new cluster mempool RPCs

test/functional/mempool_cluster.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+# Copyright (c) 2024 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test cluster mempool accessors and limits"""
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.wallet import (
+    MiniWallet,
+)
+from test_framework.util import (
+    assert_raises_rpc_error,
+)
+
+MAX_CLUSTER_COUNT = 100
+
+class MempoolClusterTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 1
+
+    def run_test(self):
+        node = self.nodes[0]
+        self.wallet = MiniWallet(node)
+
+        node = self.nodes[0]
+        parent_tx = self.wallet.send_self_transfer(from_node=node)
+        utxo_to_spend = parent_tx["new_utxo"]
+        ancestors = [parent_tx["txid"]]
+        while len(node.getrawmempool()) < MAX_CLUSTER_COUNT:
+            next_tx = self.wallet.send_self_transfer(from_node=node, utxo_to_spend=utxo_to_spend)
+            # Confirm that each transaction is in the same cluster as the first.
+            assert node.getmempoolentry(next_tx['txid'])['clusterid'] == node.getmempoolentry(parent_tx['txid'])['clusterid']
+            # Confirm that there is only one cluster in the mempool.
+            assert node.getmempoolinfo()['numberofclusters'] == 1
+
+            # Confirm that the ancestors are what we expect
+            mempool_ancestors = node.getmempoolancestors(next_tx['txid'])
+            assert sorted(mempool_ancestors) == sorted(ancestors)
+
+            # Confirm that each successive transaction is added as a descendant.
+            assert all([ next_tx["txid"] in node.getmempooldescendants(x) for x in ancestors ])
+
+            # Update for next iteration
+            ancestors.append(next_tx["txid"])
+            utxo_to_spend = next_tx["new_utxo"]
+
+        assert node.getmempoolinfo()['numberofclusters'] == 1
+        assert node.getmempoolinfo()['maxclustercount'] == MAX_CLUSTER_COUNT
+        assert node.getmempoolcluster(node.getmempoolentry(parent_tx['txid'])['clusterid'])['txcount'] == MAX_CLUSTER_COUNT
+        feeratediagram = node.getmempoolfeeratediagram()
+        last_val = [0, 0]
+        for x in feeratediagram:
+            assert x['size'] > 0
+            assert last_val[0]*x['fee'] >= last_val[1]*x['size']
+            last_val = [x['size'], x['fee']]
+
+        # Test that adding one more transaction to the cluster will fail.
+        bad_tx = self.wallet.create_self_transfer(utxo_to_spend=utxo_to_spend)
+        assert_raises_rpc_error(-26, "too-large-cluster", node.sendrawtransaction, bad_tx["hex"])
+
+        # TODO: verify that the size limits are also enforced.
+
+if __name__ == '__main__':
+    MempoolClusterTest().main()

test/functional/test_runner.py

@@ -377,6 +377,7 @@
     'p2p_sendtxrcncl.py',
     'rpc_scantxoutset.py',
     'feature_unsupported_utxo_db.py',
+    'mempool_cluster.py',
     'feature_logging.py',
     'feature_anchors.py',
     'mempool_datacarrier.py',