[QA] add wallet-rbf test

Author: jonasschnelli

test/functional/test_runner.py

@@ -126,6 +126,7 @@
     'feature_cltv.py',
     'rpc_uptime.py',
     'wallet_resendwallettransactions.py',
+    'wallet_fallbackfee.py',
     'feature_minchainwork.py',
     'p2p_fingerprint.py',
     'feature_uacomment.py',

test/functional/wallet_fallbackfee.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+# Copyright (c) 2017 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 wallet replace-by-fee capabilities in conjunction with the fallbackfee."""
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import *
+
+class WalletRBFTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 1
+        self.setup_clean_chain = True
+
+    def run_test(self):
+        self.nodes[0].generate(101)
+
+        # sending a transaction without fee estimations must be possible by default on regtest
+        self.nodes[0].sendtoaddress(self.nodes[0].getnewaddress(), 1)
+
+        # test sending a tx with disabled fallback fee (must fail)
+        self.restart_node(0, extra_args=["-fallbackfee=0"])
+        assert_raises_rpc_error(-4, "Fee estimation failed", lambda: self.nodes[0].sendtoaddress(self.nodes[0].getnewaddress(), 1))
+        assert_raises_rpc_error(-4, "Fee estimation failed", lambda: self.nodes[0].fundrawtransaction(self.nodes[0].createrawtransaction([], {self.nodes[0].getnewaddress(): 1})))
+        assert_raises_rpc_error(-4, "Fee estimation failed", lambda: self.nodes[0].sendfrom("", self.nodes[0].getnewaddress(), 1))
+        assert_raises_rpc_error(-6, "Fee estimation failed", lambda: self.nodes[0].sendmany("", {self.nodes[0].getnewaddress(): 1}))
+
+if __name__ == '__main__':
+    WalletRBFTest().main()