test: run mempool_limit with --disable-wallet

Co-authored-by: Sishir Giri <sishirg27@gmail.com>

test/functional/mempool_limit.py

@@ -5,9 +5,12 @@
 """Test mempool limiting together/eviction with the wallet."""
 
 from decimal import Decimal
+from test_framework.blocktools import COINBASE_MATURITY
 
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import assert_equal, assert_greater_than, assert_raises_rpc_error, create_confirmed_utxos, create_lots_of_big_transactions, gen_return_txouts
+from test_framework.util import assert_equal, assert_greater_than, assert_raises_rpc_error, gen_return_txouts
+from test_framework.wallet import MiniWallet
+
 
 class MempoolLimitTest(BitcoinTestFramework):
     def set_test_params(self):
@@ -20,55 +23,56 @@ def set_test_params(self):
         ]]
         self.supports_cli = False
 
-    def skip_test_if_missing_module(self):
-        self.skip_if_no_wallet()
-
     def run_test(self):
         txouts = gen_return_txouts()
-        relayfee = self.nodes[0].getnetworkinfo()['relayfee']
+
+        node = self.nodes[0]
+        miniwallet = MiniWallet(node)
+        relayfee = node.getnetworkinfo()['relayfee']
 
         self.log.info('Check that mempoolminfee is minrelytxfee')
-        assert_equal(self.nodes[0].getmempoolinfo()['minrelaytxfee'], Decimal('0.00001000'))
-        assert_equal(self.nodes[0].getmempoolinfo()['mempoolminfee'], Decimal('0.00001000'))
+        assert_equal(node.getmempoolinfo()['minrelaytxfee'], Decimal('0.00001000'))
+        assert_equal(node.getmempoolinfo()['mempoolminfee'], Decimal('0.00001000'))
+
+        # Generate 92 UTXOs to flood the mempool
+        # 1 to create a tx initially that will be evicted from the mempool later
+        # 90 with a fee rate much higher than the previous UTXO (3 batches of 30 with increasing fee rate)
+        # And 1 more to verify that this tx does not get added to the mempool with a fee rate less than the mempoolminfee
+        miniwallet.generate(1 + (3 * 30) + 1)
 
-        txids = []
-        utxos = create_confirmed_utxos(relayfee, self.nodes[0], 91)
+        # Mine 99 blocks so that the UTXOs are allowed to be spent
+        node.generate(COINBASE_MATURITY - 1)
 
         self.log.info('Create a mempool tx that will be evicted')
-        us0 = utxos.pop()
-        inputs = [{ "txid" : us0["txid"], "vout" : us0["vout"]}]
-        outputs = {self.nodes[0].getnewaddress() : 0.0001}
-        tx = self.nodes[0].createrawtransaction(inputs, outputs)
-        self.nodes[0].settxfee(relayfee) # specifically fund this tx with low fee
-        txF = self.nodes[0].fundrawtransaction(tx)
-        self.nodes[0].settxfee(0) # return to automatic fee selection
-        txFS = self.nodes[0].signrawtransactionwithwallet(txF['hex'])
-        txid = self.nodes[0].sendrawtransaction(txFS['hex'])
-
-        relayfee = self.nodes[0].getnetworkinfo()['relayfee']
-        base_fee = relayfee*100
-        for i in range (3):
-            txids.append([])
-            txids[i] = create_lots_of_big_transactions(self.nodes[0], txouts, utxos[30*i:30*i+30], 30, (i+1)*base_fee)
+        tx_to_be_evicted_id = miniwallet.send_self_transfer(
+            from_node=node, fee_rate=relayfee
+        )["txid"]
+
+        # Increase the tx fee rate massively now to give the next transactions a higher priority in the mempool
+        base_fee = relayfee*1000
+
+        self.log.info('Fill up the mempool with txs with higher fee rate')
+        no_of_large_tx_created = 0
+        for batch_of_txid in range(1,4):
+            # Increment the tx fee rate gradually by a factor of (base_fee) for each batch of 30 transactions
+            no_of_large_tx_created += miniwallet.create_large_transactions(
+                node, txouts, 30, batch_of_txid * base_fee
+            )
 
         self.log.info('The tx should be evicted by now')
-        assert txid not in self.nodes[0].getrawmempool()
-        txdata = self.nodes[0].gettransaction(txid)
-        assert txdata['confirmations'] ==  0  #confirmation should still be 0
+        # The number of transactions created should be greater than the ones present in the mempool
+        assert_greater_than(no_of_large_tx_created, len(node.getrawmempool()))
+        # Initial tx created should not be present in the mempool anymore as it had a lower fee rate
+        assert tx_to_be_evicted_id not in node.getrawmempool()
 
-        self.log.info('Check that mempoolminfee is larger than minrelytxfee')
-        assert_equal(self.nodes[0].getmempoolinfo()['minrelaytxfee'], Decimal('0.00001000'))
-        assert_greater_than(self.nodes[0].getmempoolinfo()['mempoolminfee'], Decimal('0.00001000'))
+        self.log.info('Check that mempoolminfee is larger than minrelaytxfee')
+        assert_equal(node.getmempoolinfo()['minrelaytxfee'], Decimal('0.00001000'))
+        assert_greater_than(node.getmempoolinfo()['mempoolminfee'], Decimal('0.00001000'))
 
+        # Deliberately tries to create a tx with a fee less that the minimum mempool fee to assert that it does not get added to the mempool
         self.log.info('Create a mempool tx that will not pass mempoolminfee')
-        us0 = utxos.pop()
-        inputs = [{ "txid" : us0["txid"], "vout" : us0["vout"]}]
-        outputs = {self.nodes[0].getnewaddress() : 0.0001}
-        tx = self.nodes[0].createrawtransaction(inputs, outputs)
-        # specifically fund this tx with a fee < mempoolminfee, >= than minrelaytxfee
-        txF = self.nodes[0].fundrawtransaction(tx, {'feeRate': relayfee})
-        txFS = self.nodes[0].signrawtransactionwithwallet(txF['hex'])
-        assert_raises_rpc_error(-26, "mempool min fee not met", self.nodes[0].sendrawtransaction, txFS['hex'])
+        assert_raises_rpc_error(-26,"mempool min fee not met",miniwallet.send_self_transfer,from_node=node,fee_rate=relayfee,mempool_valid=False,)
+
 
 if __name__ == '__main__':
     MempoolLimitTest().main()

test/functional/test_framework/wallet.py

@@ -19,6 +19,7 @@
     CTxInWitness,
     CTxOut,
     tx_from_hex,
+    from_hex,
 )
 from test_framework.script import (
     CScript,
@@ -182,6 +183,26 @@ def sendrawtransaction(self, *, from_node, tx_hex):
         from_node.sendrawtransaction(tx_hex)
         self.scan_tx(from_node.decoderawtransaction(tx_hex))
 
+    def create_large_transactions(
+        self, node, array_of_large_tx, no_of_tx_ids, fee_rate
+    ):
+        # Create large transactions by appending txouts in vout
+        no_of_tx_created = 0
+        for _ in range(no_of_tx_ids):
+            # Create a self transfer here to get the tx details and then append the vout to increase the tx size
+            hex = self.create_self_transfer(from_node=node, fee_rate=fee_rate)['hex']
+            # Converts it into a CTransaction() instance to append the vouts
+            tx_instance = from_hex(CTransaction(), hex)
+            for txout in array_of_large_tx:
+                tx_instance.vout.append(txout)
+            tx_hex = tx_instance.serialize().hex()
+            # Serializes and sends the tx to the nodes
+            self.sendrawtransaction(from_node=node, tx_hex=tx_hex)
+            no_of_tx_created += 1
+        assert_equal(no_of_tx_created,no_of_tx_ids)
+        return no_of_tx_created
+
+
 def make_chain(node, address, privkeys, parent_txid, parent_value, n=0, parent_locking_script=None, fee=DEFAULT_FEE):
     """Build a transaction that spends parent_txid.vout[n] and produces one output with
     amount = parent_value with a fee deducted.