test: Use MiniWalet in p2p_feefilter

2 files changed, 74 insertions, 12 deletions

diff --git a/test/functional/p2p_feefilter.py b/test/functional/p2p_feefilter.py
index fc77af2f10..b5f4df299a 100755
--- a/test/functional/p2p_feefilter.py
+++ b/test/functional/p2p_feefilter.py
@@ -10,6 +10,7 @@ from test_framework.messages import MSG_TX, MSG_WTX, msg_feefilter
 from test_framework.mininode import mininode_lock, P2PInterface
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import assert_equal
+from test_framework.wallet import MiniWallet
 
 
 class FeefilterConn(P2PInterface):
@@ -57,9 +58,6 @@ class FeeFilterTest(BitcoinTestFramework):
             "-whitelist=noban@127.0.0.1",
         ]] * self.num_nodes
 
-    def skip_test_if_missing_module(self):
-        self.skip_if_no_wallet()
-
     def run_test(self):
         self.test_feefilter_forcerelay()
         self.test_feefilter()
@@ -79,12 +77,15 @@ class FeeFilterTest(BitcoinTestFramework):
     def test_feefilter(self):
         node1 = self.nodes[1]
         node0 = self.nodes[0]
+        miniwallet = MiniWallet(node1)
+        # Add enough mature utxos to the wallet, so that all txs spend confirmed coins
+        miniwallet.generate(5)
+        node1.generate(100)
 
         conn = self.nodes[0].add_p2p_connection(TestP2PConn())
 
         self.log.info("Test txs paying 0.2 sat/byte are received by test connection")
-        node1.settxfee(Decimal("0.00000200"))
-        txids = [node1.sendtoaddress(node1.getnewaddress(), 1) for _ in range(3)]
+        txids = [miniwallet.send_self_transfer(fee_rate=Decimal('0.00000200'), from_node=node1)['wtxid'] for _ in range(3)]
         conn.wait_for_invs_to_match(txids)
         conn.clear_invs()
 
@@ -92,14 +93,12 @@ class FeeFilterTest(BitcoinTestFramework):
         conn.send_and_ping(msg_feefilter(150))
 
         self.log.info("Test txs paying 0.15 sat/byte are received by test connection")
-        node1.settxfee(Decimal("0.00000150"))
-        txids = [node1.sendtoaddress(node1.getnewaddress(), 1) for _ in range(3)]
+        txids = [miniwallet.send_self_transfer(fee_rate=Decimal('0.00000150'), from_node=node1)['wtxid'] for _ in range(3)]
         conn.wait_for_invs_to_match(txids)
         conn.clear_invs()
 
         self.log.info("Test txs paying 0.1 sat/byte are no longer received by test connection")
-        node1.settxfee(Decimal("0.00000100"))
-        [node1.sendtoaddress(node1.getnewaddress(), 1) for _ in range(3)]
+        txids = [miniwallet.send_self_transfer(fee_rate=Decimal('0.00000100'), from_node=node1)['wtxid'] for _ in range(3)]
         self.sync_mempools()  # must be sure node 0 has received all txs
 
         # Send one transaction from node0 that should be received, so that we
@@ -109,14 +108,13 @@ class FeeFilterTest(BitcoinTestFramework):
         # to 35 entries in an inv, which means that when this next transaction
         # is eligible for relay, the prior transactions from node1 are eligible
         # as well.
-        node0.settxfee(Decimal("0.00020000"))
-        txids = [node0.sendtoaddress(node0.getnewaddress(), 1)]
+        txids = [miniwallet.send_self_transfer(fee_rate=Decimal('0.00020000'), from_node=node0)['wtxid'] for _ in range(3)]
         conn.wait_for_invs_to_match(txids)
         conn.clear_invs()
 
         self.log.info("Remove fee filter and check txs are received again")
         conn.send_and_ping(msg_feefilter(0))
-        txids = [node1.sendtoaddress(node1.getnewaddress(), 1) for _ in range(3)]
+        txids = [miniwallet.send_self_transfer(fee_rate=Decimal('0.00020000'), from_node=node1)['wtxid'] for _ in range(3)]
         conn.wait_for_invs_to_match(txids)
         conn.clear_invs()
 
diff --git a/test/functional/test_framework/wallet.py b/test/functional/test_framework/wallet.py
new file mode 100644
index 0000000000..c4a9d2138d
--- /dev/null
+++ b/test/functional/test_framework/wallet.py
@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+# Copyright (c) 2020 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""A limited-functionality wallet, which may replace a real wallet in tests"""
+
+from decimal import Decimal
+from test_framework.address import ADDRESS_BCRT1_P2WSH_OP_TRUE
+from test_framework.messages import (
+    COIN,
+    COutPoint,
+    CTransaction,
+    CTxIn,
+    CTxInWitness,
+    CTxOut,
+)
+from test_framework.script import (
+    CScript,
+    OP_TRUE,
+)
+from test_framework.util import (
+    assert_equal,
+    hex_str_to_bytes,
+    satoshi_round,
+)
+
+
+class MiniWallet:
+    def __init__(self, test_node):
+        self._test_node = test_node
+        self._utxos = []
+        self._address = ADDRESS_BCRT1_P2WSH_OP_TRUE
+        self._scriptPubKey = hex_str_to_bytes(self._test_node.validateaddress(self._address)['scriptPubKey'])
+
+    def generate(self, num_blocks):
+        """Generate blocks with coinbase outputs to the internal address, and append the outputs to the internal list"""
+        blocks = self._test_node.generatetoaddress(num_blocks, self._address)
+        for b in blocks:
+            cb_tx = self._test_node.getblock(blockhash=b, verbosity=2)['tx'][0]
+            self._utxos.append({'txid': cb_tx['txid'], 'vout': 0, 'value': cb_tx['vout'][0]['value']})
+        return blocks
+
+    def send_self_transfer(self, *, fee_rate, from_node):
+        """Create and send a tx with the specified fee_rate. Fee may be exact or at most one satoshi higher than needed."""
+        self._utxos = sorted(self._utxos, key=lambda k: -k['value'])
+        largest_utxo = self._utxos.pop()  # Pick the largest utxo and hope it covers the fee
+        vsize = Decimal(96)
+        send_value = satoshi_round(largest_utxo['value'] - fee_rate * (vsize / 1000))
+        fee = largest_utxo['value'] - send_value
+        assert (send_value > 0)
+
+        tx = CTransaction()
+        tx.vin = [CTxIn(COutPoint(int(largest_utxo['txid'], 16), largest_utxo['vout']))]
+        tx.vout = [CTxOut(int(send_value * COIN), self._scriptPubKey)]
+        tx.wit.vtxinwit = [CTxInWitness()]
+        tx.wit.vtxinwit[0].scriptWitness.stack = [CScript([OP_TRUE])]
+        tx_hex = tx.serialize().hex()
+
+        txid = from_node.sendrawtransaction(tx_hex)
+        self._utxos.append({'txid': txid, 'vout': 0, 'value': send_value})
+        tx_info = from_node.getmempoolentry(txid)
+        assert_equal(tx_info['vsize'], vsize)
+        assert_equal(tx_info['fee'], fee)
+        return {'txid': txid, 'wtxid': tx_info['wtxid'], 'hex': tx_hex}