Create feelimit.py test

Create feelimit.py test to verify the updated fee values now rounding has been eliminated.

qa/pull-tester/rpc-tests.py

@@ -156,6 +156,7 @@ testScripts = [
     'import-rescan.py',
     'harddustlimit.py',
     'paytxfee.py',
+    'feelimit.py',
     # While fee bumping should work in Doge, these tests depend on free transactions, which we don't support.
     # Disable until we can do a full rewrite of the tests (possibly upstream), or revise fee schedule, or something
     'bumpfee.py',

qa/rpc-tests/feelimit.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+# Copyright (c) 2021 The Dogecoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Fee limit QA test.
+# Tests nodes under fee limit, verifies fee rounding
+"""
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import *
+from decimal import Decimal
+
+class FeeLimitTest(BitcoinTestFramework):
+
+    def __init__(self):
+        super().__init__()
+        self.setup_clean_chain = True
+        self.num_nodes = 2
+
+    def setup_network(self, split=False):
+        self.nodes = []
+        self.nodes.append(start_node(0, self.options.tmpdir, []))
+        self.nodes.append(start_node(1, self.options.tmpdir, []))
+
+        connect_nodes_bi(self.nodes,0,1)
+
+        self.is_network_split=False
+        self.sync_all()
+
+    def run_test(self):
+        # mine some blocks
+        self.nodes[0].generate(101)
+        self.sync_all()
+
+        # Output address
+        addr_to = self.nodes[1].getnewaddress()
+        lower_fee_per_kb = Decimal("0.001")
+
+        # Force generating a transaction with 1.14.5-like fees by manually building the tx
+        utx = self.nodes[0].listunspent()[0]
+        inputs  = [ {'txid' : utx['txid'], 'vout' : utx['vout']}]
+        outputs = { addr_to : utx['amount'] - Decimal("1.0") }
+        rawtx   = self.nodes[0].createrawtransaction(inputs, outputs)
+
+        # Work out how big this transaction would be, then change the output to match
+        tx_size = count_bytes(self.nodes[0].signrawtransaction(rawtx)['hex'])
+        fee = lower_fee_per_kb * (tx_size + 1) / Decimal("1000")
+        outputs = { addr_to : utx['amount'] - fee }
+        rawtx   = self.nodes[0].createrawtransaction(inputs, outputs)
+        signedtx = self.nodes[0].signrawtransaction(rawtx)
+        self.nodes[0].sendrawtransaction(signedtx["hex"])
+
+        # Sync all of the nodes
+        self.sync_all()
+
+        # Check if the TX made it to node 2
+        assert_equal(self.nodes[1].getmempoolinfo()['size'], 1)
+        assert_equal(self.nodes[0].getmempoolinfo()['size'], 1)
+
+        # Force generating a transaction with fees which are too low to relay
+        too_low_fee = lower_fee_per_kb * (tx_size - 4) / Decimal("1000")
+        utx = self.nodes[0].listunspent()[0]
+        inputs  = [ {'txid' : utx['txid'], 'vout' : utx['vout']}]
+        outputs = { self.nodes[1].getnewaddress() : utx['amount'] - too_low_fee }
+        rawtx   = self.nodes[0].createrawtransaction(inputs, outputs)
+        signedtx = self.nodes[0].signrawtransaction(rawtx)
+        self.nodes[0].sendrawtransaction(signedtx["hex"])
+
+        # wait 10 seconds to sync mempools
+        time.sleep(10)
+
+        # Check the TX did not relay, so is only on node 0
+        assert_equal(self.nodes[1].getmempoolinfo()['size'], 1)
+        assert_equal(self.nodes[0].getmempoolinfo()['size'], 2)
+
+if __name__ == '__main__':
+    FeeLimitTest().main()