fix: Grab the feature from the init message if it is not specified

This commit improves the method for generating the sequence
of events needed to connect to a node from the sender side.

Specifically, we can now retrieve the same feature
that the node sends to the runner.

This is useful because if the features do not match,
the connection must be closed.

Signed-off-by: Vincenzo Palazzo <[email protected]>

lnprototest/stash/stash.py

@@ -1,10 +1,12 @@
-from lnprototest import Runner, Event, Side, SpecFileError, Funding
-from typing import Callable, Optional, Any
-from pyln.proto.message import Message
 import functools
 import time
 import coincurve
 
+from typing import Callable, Optional, Any
+from pyln.proto.message import Message
+
+from lnprototest import Runner, Event, Side, SpecFileError, Funding
+
 
 def commitsig_to_send() -> Callable[[Runner, Event, str], str]:
     """Get the appropriate signature for the local side to send to the remote"""
@@ -275,12 +277,15 @@ def _funding_close_tx(runner: Runner, event: Event, field: str) -> str:
     return _funding_close_tx
 
 
-def stash_field_from_event(stash_key: str) -> Callable[[Runner, Event, str], str]:
+def stash_field_from_event(
+    stash_key: str, field_name: Optional[str] = None, dummy_val: Optional[Any] = None
+) -> Callable[[Runner, Event, str], str]:
     """Generic stash function to get the information back from a previous event"""
 
     def _stash_field_from_event(runner: Runner, event: Event, field: str) -> str:
         if runner._is_dummy():
-            return "0"
+            return dummy_val
+        field = field if field_name is None else field_name
         return runner.get_stash(event, stash_key).fields[field]
 
     return _stash_field_from_event

lnprototest/utils/ln_spec_utils.py

@@ -8,7 +8,7 @@
 
 author: Vincenzo PAlazzo https://github.com/vincenzopalazzo
 """
-from typing import List
+from typing import List, Optional
 
 
 class LightningUtils:
@@ -49,11 +49,12 @@ def connect_to_node_helper(
     runner: "Runner",
     tx_spendable: str,
     conn_privkey: str = "02",
-    global_features="",
-    features: str = "",
+    global_features: Optional[str] = None,
+    features: Optional[str] = None,
 ) -> List["Event"]:
     """Helper function to make a connection with the node"""
     from lnprototest.utils.bitcoin_utils import tx_spendable
+    from lnprototest.stash import stash_field_from_event
     from lnprototest import (
         Connect,
         Block,
@@ -65,7 +66,15 @@ def connect_to_node_helper(
         Block(blockheight=102, txs=[tx_spendable]),
         Connect(connprivkey=conn_privkey),
         ExpectMsg("init"),
-        Msg("init", globalfeatures=global_features, features=features),
+        Msg(
+            "init",
+            globalfeatures=stash_field_from_event("init", dummy_val="")
+            if global_features is None
+            else global_features,
+            features=stash_field_from_event("init", dummy_val="")
+            if features is None
+            else features,
+        ),
     ]
 
 

tests/test_bolt2-01-open_channel.py

@@ -112,7 +112,7 @@ def test_open_channel_from_accepter_side(runner: Runner) -> None:
             delayed_payment_basepoint=remote_delayed_payment_basepoint(),
             htlc_basepoint=remote_htlc_basepoint(),
             first_per_commitment_point=remote_per_commitment_point(0),
-            minimum_depth=stash_field_from_event("accept_channel"),
+            minimum_depth=stash_field_from_event("accept_channel", dummy_val=3),
             channel_reserve_satoshis=9998,
         ),
         # Ignore unknown odd messages