test: Add test for maxtxfee option

Author: MarcoFalke

test/functional/wallet_create_tx.py

@@ -6,6 +6,7 @@
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_equal,
+    assert_raises_rpc_error,
 )
 from test_framework.blocktools import (
     TIME_GENESIS_BLOCK,
@@ -26,6 +27,10 @@ def run_test(self):
         self.nodes[0].generate(200)
         self.nodes[0].setmocktime(0)
 
+        self.test_anti_fee_sniping()
+        self.test_tx_size_too_large()
+
+    def test_anti_fee_sniping(self):
         self.log.info('Check that we have some (old) blocks and that anti-fee-sniping is disabled')
         assert_equal(self.nodes[0].getblockchaininfo()['blocks'], 200)
         txid = self.nodes[0].sendtoaddress(self.nodes[0].getnewaddress(), 1)
@@ -38,6 +43,40 @@ def run_test(self):
         tx = self.nodes[0].decoderawtransaction(self.nodes[0].gettransaction(txid)['hex'])
         assert 0 < tx['locktime'] <= 201
 
+    def test_tx_size_too_large(self):
+        # More than 10kB of outputs, so that we hit -maxtxfee with a high feerate
+        outputs = {self.nodes[0].getnewaddress(address_type='bech32'): 0.000025 for i in range(400)}
+        raw_tx = self.nodes[0].createrawtransaction(inputs=[], outputs=outputs)
+
+        for fee_setting in ['-minrelaytxfee=0.01', '-mintxfee=0.01', '-paytxfee=0.01']:
+            self.log.info('Check maxtxfee in combination with {}'.format(fee_setting))
+            self.restart_node(0, extra_args=[fee_setting])
+            assert_raises_rpc_error(
+                -6,
+                "Fee exceeds maximum configured by -maxtxfee",
+                lambda: self.nodes[0].sendmany(dummy="", amounts=outputs),
+            )
+            assert_raises_rpc_error(
+                -4,
+                "Fee exceeds maximum configured by -maxtxfee",
+                lambda: self.nodes[0].fundrawtransaction(hexstring=raw_tx),
+            )
+
+        self.log.info('Check maxtxfee in combination with settxfee')
+        self.restart_node(0)
+        self.nodes[0].settxfee(0.01)
+        assert_raises_rpc_error(
+            -6,
+            "Fee exceeds maximum configured by -maxtxfee",
+            lambda: self.nodes[0].sendmany(dummy="", amounts=outputs),
+        )
+        assert_raises_rpc_error(
+            -4,
+            "Fee exceeds maximum configured by -maxtxfee",
+            lambda: self.nodes[0].fundrawtransaction(hexstring=raw_tx),
+        )
+        self.nodes[0].settxfee(0)
+
 
 if __name__ == '__main__':
     CreateTxWalletTest().main()