set initial trampoline fee level to 1 unless we are testing

electrum/lnworker.py

@@ -185,6 +185,8 @@ LNGOSSIP_FEATURES = BASE_FEATURES\
 
 class LNWorker(Logger, NetworkRetryManager[LNPeerAddr]):
 
+    INITIAL_TRAMPOLINE_FEE_LEVEL = 1 # only used for trampoline payments. set to 0 in tests.
+
     def __init__(self, xprv, features: LnFeatures):
         Logger.__init__(self)
         NetworkRetryManager.__init__(
@@ -1150,7 +1152,7 @@ class LNWallet(LNWorker):
                 raise OnionRoutingFailure(code=OnionFailureCode.TRAMPOLINE_EXPIRY_TOO_SOON, data=b'')
 
         self.logs[payment_hash.hex()] = log = []
-        trampoline_fee_level = 0   # only used for trampoline payments
+        trampoline_fee_level = self.INITIAL_TRAMPOLINE_FEE_LEVEL
         use_two_trampolines = True # only used for pay to legacy
 
         amount_inflight = 0  # what we sent in htlcs (that receiver gets, without fees)

electrum/tests/test_lnpeer.py

@@ -116,6 +116,7 @@ class MockWallet:
 class MockLNWallet(Logger, NetworkRetryManager[LNPeerAddr]):
     MPP_EXPIRY = 2  # HTLC timestamps are cast to int, so this cannot be 1
     TIMEOUT_SHUTDOWN_FAIL_PENDING_HTLCS = 0
+    INITIAL_TRAMPOLINE_FEE_LEVEL = 0
 
     def __init__(self, *, local_keypair: Keypair, chans: Iterable['Channel'], tx_queue, name):
         self.name = name