lnrouter tests: add another channel to graph

We need another channel to have routes with three hops. This can be
later used to test payment successes.

electrum/tests/test_lnrouter.py

@@ -4,6 +4,7 @@ import shutil
 import asyncio
 
 from electrum.util import bh2u, bfh, create_and_start_event_loop
+from electrum.lnutil import ShortChannelID
 from electrum.lnonion import (OnionHopsDataSingle, new_onion_packet,
                               process_onion_packet, _decode_onion_error, decode_onion_error,
                               OnionFailureCode, OnionPacket)
@@ -16,6 +17,14 @@ from . import TestCaseForTestnet
 from .test_bitcoin import needs_test_with_all_chacha20_implementations
 
 
+def channel(number: int) -> ShortChannelID:
+    return ShortChannelID(bfh(format(number, '016x')))
+
+
+def node(character: str) -> bytes:
+    return b'\x02' + f'{character}'.encode() * 32
+
+
 class Test_LNRouter(TestCaseForTestnet):
 
     def setUp(self):
@@ -28,7 +37,24 @@ class Test_LNRouter(TestCaseForTestnet):
         self._loop_thread.join(timeout=1)
         super().tearDown()
 
-    def test_find_path_for_payment(self):
+    def prepare_graph(self):
+        """
+        Network topology with channel ids:
+                3
+            A  ---  B
+            |    2/ |
+          6 |   E   | 1
+            | /5 \7 |
+            D  ---  C
+                4
+        valid routes from A -> E:
+        A -3-> B -2-> E
+        A -6-> D -5-> E
+        A -6-> D -4-> C -7-> E
+        A -3-> B -1-> C -7-> E
+        A -6-> D -4-> C -1-> B -2-> E
+        A -3-> B -1-> C -4-> D -5-> E
+        """
         class fake_network:
             config = self.config
             asyncio_loop = asyncio.get_event_loop()
@@ -37,67 +63,95 @@ class Test_LNRouter(TestCaseForTestnet):
             interface = None
         fake_network.channel_db = lnrouter.ChannelDB(fake_network())
         fake_network.channel_db.data_loaded.set()
-        cdb = fake_network.channel_db
-        path_finder = lnrouter.LNPathFinder(cdb)
-        self.assertEqual(cdb.num_channels, 0)
-        cdb.add_channel_announcements({'node_id_1': b'\x02bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb', 'node_id_2': b'\x02cccccccccccccccccccccccccccccccc',
-                                     'bitcoin_key_1': b'\x02bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb', 'bitcoin_key_2': b'\x02cccccccccccccccccccccccccccccccc',
-                                     'short_channel_id': bfh('0000000000000001'),
-                                     'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
-                                     'len': 0, 'features': b''}, trusted=True)
-        self.assertEqual(cdb.num_channels, 1)
-        cdb.add_channel_announcements({'node_id_1': b'\x02bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb', 'node_id_2': b'\x02eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee',
-                                     'bitcoin_key_1': b'\x02bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb', 'bitcoin_key_2': b'\x02eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee',
-                                     'short_channel_id': bfh('0000000000000002'),
-                                     'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
-                                     'len': 0, 'features': b''}, trusted=True)
-        cdb.add_channel_announcements({'node_id_1': b'\x02aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa', 'node_id_2': b'\x02bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb',
-                                     'bitcoin_key_1': b'\x02aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa', 'bitcoin_key_2': b'\x02bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb',
-                                     'short_channel_id': bfh('0000000000000003'),
-                                     'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
-                                     'len': 0, 'features': b''}, trusted=True)
-        cdb.add_channel_announcements({'node_id_1': b'\x02cccccccccccccccccccccccccccccccc', 'node_id_2': b'\x02dddddddddddddddddddddddddddddddd',
-                                     'bitcoin_key_1': b'\x02cccccccccccccccccccccccccccccccc', 'bitcoin_key_2': b'\x02dddddddddddddddddddddddddddddddd',
-                                     'short_channel_id': bfh('0000000000000004'),
-                                     'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
-                                     'len': 0, 'features': b''}, trusted=True)
-        cdb.add_channel_announcements({'node_id_1': b'\x02dddddddddddddddddddddddddddddddd', 'node_id_2': b'\x02eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee',
-                                     'bitcoin_key_1': b'\x02dddddddddddddddddddddddddddddddd', 'bitcoin_key_2': b'\x02eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee',
-                                     'short_channel_id': bfh('0000000000000005'),
-                                     'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
-                                     'len': 0, 'features': b''}, trusted=True)
-        cdb.add_channel_announcements({'node_id_1': b'\x02aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa', 'node_id_2': b'\x02dddddddddddddddddddddddddddddddd',
-                                     'bitcoin_key_1': b'\x02aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa', 'bitcoin_key_2': b'\x02dddddddddddddddddddddddddddddddd',
-                                     'short_channel_id': bfh('0000000000000006'),
-                                     'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
-                                     'len': 0, 'features': b''}, trusted=True)
+        self.cdb = fake_network.channel_db
+        self.path_finder = lnrouter.LNPathFinder(self.cdb)
+        self.assertEqual(self.cdb.num_channels, 0)
+        self.cdb.add_channel_announcements({
+            'node_id_1': node('b'), 'node_id_2': node('c'),
+            'bitcoin_key_1': node('b'), 'bitcoin_key_2': node('c'),
+            'short_channel_id': channel(1),
+            'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
+            'len': 0, 'features': b''
+        }, trusted=True)
+        self.assertEqual(self.cdb.num_channels, 1)
+        self.cdb.add_channel_announcements({
+            'node_id_1': node('b'), 'node_id_2': node('e'),
+            'bitcoin_key_1': node('b'), 'bitcoin_key_2': node('e'),
+            'short_channel_id': channel(2),
+            'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
+            'len': 0, 'features': b''
+        }, trusted=True)
+        self.cdb.add_channel_announcements({
+            'node_id_1': node('a'), 'node_id_2': node('b'),
+            'bitcoin_key_1': node('a'), 'bitcoin_key_2': node('b'),
+            'short_channel_id': channel(3),
+            'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
+            'len': 0, 'features': b''
+        }, trusted=True)
+        self.cdb.add_channel_announcements({
+            'node_id_1': node('c'), 'node_id_2': node('d'),
+            'bitcoin_key_1': node('c'), 'bitcoin_key_2': node('d'),
+            'short_channel_id': channel(4),
+            'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
+            'len': 0, 'features': b''
+        }, trusted=True)
+        self.cdb.add_channel_announcements({
+            'node_id_1': node('d'), 'node_id_2': node('e'),
+            'bitcoin_key_1': node('d'), 'bitcoin_key_2': node('e'),
+            'short_channel_id': channel(5),
+            'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
+            'len': 0, 'features': b''
+        }, trusted=True)
+        self.cdb.add_channel_announcements({
+            'node_id_1': node('a'), 'node_id_2': node('d'),
+            'bitcoin_key_1': node('a'), 'bitcoin_key_2': node('d'),
+            'short_channel_id': channel(6),
+            'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
+            'len': 0, 'features': b''
+        }, trusted=True)
+        self.cdb.add_channel_announcements({
+            'node_id_1': node('c'), 'node_id_2': node('e'),
+            'bitcoin_key_1': node('c'), 'bitcoin_key_2': node('e'),
+            'short_channel_id': channel(7),
+            'chain_hash': BitcoinTestnet.rev_genesis_bytes(),
+            'len': 0, 'features': b''
+        }, trusted=True)
         def add_chan_upd(payload):
-            cdb.add_channel_update(payload, verify=False)
-        add_chan_upd({'short_channel_id': bfh('0000000000000001'), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        add_chan_upd({'short_channel_id': bfh('0000000000000001'), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        add_chan_upd({'short_channel_id': bfh('0000000000000002'), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 99, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        add_chan_upd({'short_channel_id': bfh('0000000000000002'), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        add_chan_upd({'short_channel_id': bfh('0000000000000003'), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        add_chan_upd({'short_channel_id': bfh('0000000000000003'), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        add_chan_upd({'short_channel_id': bfh('0000000000000004'), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        add_chan_upd({'short_channel_id': bfh('0000000000000004'), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        add_chan_upd({'short_channel_id': bfh('0000000000000005'), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        add_chan_upd({'short_channel_id': bfh('0000000000000005'), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 999, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        add_chan_upd({'short_channel_id': bfh('0000000000000006'), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 99999999, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        add_chan_upd({'short_channel_id': bfh('0000000000000006'), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
-        path = path_finder.find_path_for_payment(
-            nodeA=b'\x02aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa',
-            nodeB=b'\x02eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee',
-            invoice_amount_msat=100000)
-        self.assertEqual([PathEdge(start_node=b'\x02aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa', end_node=b'\x02bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb', short_channel_id=bfh('0000000000000003')),
-                          PathEdge(start_node=b'\x02bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb', end_node=b'\x02eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee', short_channel_id=bfh('0000000000000002')),
-                         ], path)
-        route = path_finder.create_route_from_path(path)
-        self.assertEqual(b'\x02bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb', route[0].node_id)
-        self.assertEqual(bfh('0000000000000003'),                 route[0].short_channel_id)
+            self.cdb.add_channel_update(payload, verify=False)
+        add_chan_upd({'short_channel_id': channel(1), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(1), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(2), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 99, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(2), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(3), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(3), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(4), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(4), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(5), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(5), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 999, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(6), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 200, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(6), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(7), 'message_flags': b'\x00', 'channel_flags': b'\x00', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
+        add_chan_upd({'short_channel_id': channel(7), 'message_flags': b'\x00', 'channel_flags': b'\x01', 'cltv_expiry_delta': 10, 'htlc_minimum_msat': 250, 'fee_base_msat': 100, 'fee_proportional_millionths': 150, 'chain_hash': BitcoinTestnet.rev_genesis_bytes(), 'timestamp': 0})
 
-        cdb.stop()
-        asyncio.run_coroutine_threadsafe(cdb.stopped_event.wait(), self.asyncio_loop).result()
+    def test_find_path_for_payment(self):
+        self.prepare_graph()
+        amount_to_send = 100000
+
+        path = self.path_finder.find_path_for_payment(
+            nodeA=node('a'),
+            nodeB=node('e'),
+            invoice_amount_msat=amount_to_send)
+        self.assertEqual([
+            PathEdge(start_node=node('a'), end_node=node('b'), short_channel_id=channel(3)),
+            PathEdge(start_node=node('b'), end_node=node('e'), short_channel_id=channel(2)),
+        ], path)
+
+        route = self.path_finder.create_route_from_path(path)
+        self.assertEqual(node('b'), route[0].node_id)
+        self.assertEqual(channel(3), route[0].short_channel_id)
+
+        self.cdb.stop()
+        asyncio.run_coroutine_threadsafe(self.cdb.stopped_event.wait(), self.asyncio_loop).result()
 
     @needs_test_with_all_chacha20_implementations
     def test_new_onion_packet_legacy(self):