lnutil: add docstring and more tests for extract_nodeid

electrum/gui/qml/qechannelopener.py

@@ -129,13 +129,13 @@ class QEChannelOpener(QObject, AuthMixin):
         try:
             self.nodeid_to_lnpeer(nodeid)
         except Exception as e:
-            self._logger.debug(repr(e))
+            self._logger.debug(f"invalid nodeid. {e!r}")
             return False
         return True
 
     def nodeid_to_lnpeer(self, nodeid):
         node_pubkey, host_port = extract_nodeid(nodeid)
-        if host_port.__contains__(':'):
+        if host_port.__contains__(':'):  # FIXME host_port can be None; can't construct LNPeerAddr then.
             host, port = host_port.split(':',1)
         else:
             host = host_port

electrum/lnutil.py

@@ -1450,7 +1450,16 @@ def split_host_port(host_port: str) -> Tuple[str, str]: # port returned as strin
         raise ConnStringFormatError(_('Port number must be decimal'))
     return host, port
 
-def extract_nodeid(connect_contents: str) -> Tuple[bytes, str]:
+
+def extract_nodeid(connect_contents: str) -> Tuple[bytes, Optional[str]]:
+    """Takes a connection-string-like str, and returns a tuple (node_id, rest),
+    where rest is typically a host (with maybe port). Examples:
+    - extract_nodeid(pubkey@host:port) == (pubkey, host:port)
+    - extract_nodeid(pubkey@host) == (pubkey, host)
+    - extract_nodeid(pubkey) == (pubkey, None)
+    - extract_nodeid(bolt11_invoice) == (pubkey, None)
+    Can raise ConnStringFormatError.
+    """
     rest = None
     try:
         # connection string?

electrum/tests/test_lnutil.py

@@ -2,6 +2,7 @@ import unittest
 import json
 
 from electrum import bitcoin
+from electrum import ecc
 from electrum.json_db import StoredDict
 from electrum.lnutil import (RevocationStore, get_per_commitment_secret_from_seed, make_offered_htlc,
                              make_received_htlc, make_commitment, make_htlc_tx_witness, make_htlc_tx_output,
@@ -756,11 +757,23 @@ class TestLNUtil(ElectrumTestCase):
             split_host_port("electrum.org:")
 
     def test_extract_nodeid(self):
+        pubkey1 = ecc.GENERATOR.get_public_key_bytes(compressed=True)
         with self.assertRaises(ConnStringFormatError):
             extract_nodeid("00" * 32 + "@localhost")
         with self.assertRaises(ConnStringFormatError):
             extract_nodeid("00" * 33 + "@")
+        # pubkey + host
         self.assertEqual(extract_nodeid("00" * 33 + "@localhost"), (b"\x00" * 33, "localhost"))
+        self.assertEqual(extract_nodeid(f"{pubkey1.hex()}@11.22.33.44"), (pubkey1, "11.22.33.44"))
+        self.assertEqual(extract_nodeid(f"{pubkey1.hex()}@[2001:41d0:e:734::1]"), (pubkey1, "[2001:41d0:e:734::1]"))
+        # pubkey + host + port
+        self.assertEqual(extract_nodeid(f"{pubkey1.hex()}@11.22.33.44:5555"), (pubkey1, "11.22.33.44:5555"))
+        self.assertEqual(extract_nodeid(f"{pubkey1.hex()}@[2001:41d0:e:734::1]:8888"), (pubkey1, "[2001:41d0:e:734::1]:8888"))
+        # just pubkey
+        self.assertEqual(extract_nodeid(f"{pubkey1.hex()}"), (pubkey1, None))
+        # bolt11 invoice
+        self.assertEqual(extract_nodeid("lnbc241ps9zprzpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqsp5zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zygshp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqs9qypqszrwfgrl5k3rt4q4mclc8t00p2tcjsf9pmpcq6lu5zhmampyvk43fk30eqpdm8t5qmdpzan25aqxqaqdzmy0smrtduazjcxx975vz78ccpx0qhev"),
+                         (bfh("03e7156ae33b0a208d0744199163177e909e80176e55d97a2f221ede0f934dd9ad"), None))
 
     def test_ln_features_validate_transitive_dependencies(self):
         features = LnFeatures.OPTION_DATA_LOSS_PROTECT_REQ