add get_channel_ctx to CLI, for testing breaches

electrum/commands.py

@@ -845,6 +845,15 @@ class Commands:
         coro = self.lnworker.force_close_channel(chan_id) if force else self.lnworker.close_channel(chan_id)
         return self.network.run_from_another_thread(coro)
 
+    @command('wn')
+    def get_channel_ctx(self, channel_point):
+        """ return the current commitment transaction of a channel """
+        txid, index = channel_point.split(':')
+        chan_id, _ = channel_id_from_funding_tx(txid, int(index))
+        chan = self.lnworker.channels[chan_id]
+        tx = chan.force_close_tx()
+        return tx.as_dict()
+
 def eval_bool(x: str) -> bool:
     if x == 'false': return False
     if x == 'true': return True

electrum/lnchannel.py

@@ -187,11 +187,6 @@ class Channel(PrintError):
         self.local_commitment = ctx
         if self.sweep_address is not None:
             self.local_sweeptxs = create_sweeptxs_for_our_latest_ctx(self, self.local_commitment, self.sweep_address)
-            initial = os.path.join(get_config().electrum_path(), 'initial_commitment_tx')
-            tx = self.force_close_tx().serialize_to_network()
-            if not os.path.exists(initial):
-                with open(initial, 'w') as f:
-                    f.write(tx)
 
     def set_remote_commitment(self):
         self.remote_commitment = self.current_commitment(REMOTE)

electrum/tests/regtest/regtest.sh

@@ -71,13 +71,14 @@ fi
 
 if [[ $1 == "breach" ]]; then
     bob_node=$($bob nodeid)
-    $alice open_channel $bob_node 0.15
+    channel=$($alice open_channel $bob_node 0.15)
     sleep 3
+    ctx=$($alice get_channel_ctx $channel | jq '.hex' | tr -d '"')
     bitcoin-cli generate 6 > /dev/null
     sleep 10
     request=$($bob addinvoice 0.01 "blah")
     $alice lnpay $request
-    bitcoin-cli sendrawtransaction $(cat /tmp/alice/regtest/initial_commitment_tx)
+    bitcoin-cli sendrawtransaction $ctx
     sleep 12
     bitcoin-cli generate 2 > /dev/null
     sleep 12