pytest: generalize tests.

Anchor outputs break many assumptions in our tests:

1. Remove some hardcoded numbers in favor of a fee calc, so we only have to
   change in one place.
   FIXME: This should also be done for elements!
2. Do binary search to get feerate for a given closing fee.
3. Don't assume output #0: anchor outputs perturb them.
4. Don't assume we can make 1ksat channels (anchors cost 660 sats!).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/test_closing.py

@@ -4,7 +4,7 @@ from pyln.client import RpcError
 from shutil import copyfile
 from utils import (
     only_one, sync_blockheight, wait_for, DEVELOPER, TIMEOUT,
-    account_balance, first_channel_id
+    account_balance, first_channel_id, basic_fee
 )
 
 import os
@@ -19,7 +19,7 @@ import unittest
 def test_closing(node_factory, bitcoind, chainparams):
     l1, l2 = node_factory.line_graph(2)
     chan = l1.get_channel_scid(l2)
-    fee = 5430 if not chainparams['elements'] else 8955
+    fee = basic_fee(7500) if not chainparams['elements'] else 8955
 
     l1.pay(l2, 200000000)
 
@@ -358,8 +358,20 @@ def test_closing_specified_destination(node_factory, bitcoind, chainparams):
 
 
 def closing_negotiation_step(node_factory, bitcoind, chainparams, opts):
-    orate = 29006  # closing fee negotiation starts at 21000
-    prate = 27625  # closing fee negotiation starts at 20000
+    def feerate_for(target, minimum=0, maximum=10000000):
+        """Binary search to find feerate"""
+        assert minimum != maximum
+        mid = (minimum + maximum) // 2
+        mid_fee = basic_fee(mid)
+        if mid_fee > target:
+            return feerate_for(target, minimum, mid)
+        elif mid_fee < target:
+            return feerate_for(target, mid, maximum)
+        else:
+            return mid
+
+    orate = feerate_for(21000)  # closing fee negotiation starts at 21000
+    prate = feerate_for(20000)  # closing fee negotiation starts at 20000
     opener, peer = node_factory.line_graph(2, opts=[{'feerates': (orate, orate, orate, orate)},
                                                     {'feerates': (prate, prate, prate, prate)}])
 
@@ -1672,7 +1684,7 @@ def test_onchain_all_dust(node_factory, bitcoind, executor):
 
     l1.wait_for_onchaind_broadcast('IGNORING_TINY_PAYMENT',
                                    'THEIR_UNILATERAL/OUR_HTLC')
-    l1.daemon.wait_for_log('Ignoring output 0 of .*: THEIR_UNILATERAL/OUR_HTLC')
+    l1.daemon.wait_for_log('Ignoring output .* of .*: THEIR_UNILATERAL/OUR_HTLC')
 
     # 100 deep and l2 forgets.
     bitcoind.generate_block(93)
@@ -2204,7 +2216,7 @@ def test_permfail(node_factory, bitcoind):
         return (
             len(billboard) == 2
             and billboard[0] == 'ONCHAIN:Tracking our own unilateral close'
-            and re.fullmatch(r'ONCHAIN:.* outputs unresolved: in 4 blocks will spend DELAYED_OUTPUT_TO_US \(.*:0\) using OUR_DELAYED_RETURN_TO_WALLET', billboard[1])
+            and re.fullmatch(r'ONCHAIN:.* outputs unresolved: in 4 blocks will spend DELAYED_OUTPUT_TO_US \(.*:.*\) using OUR_DELAYED_RETURN_TO_WALLET', billboard[1])
         )
     wait_for(check_billboard)
 

tests/test_connection.py

@@ -8,7 +8,7 @@ from utils import (
     DEVELOPER, only_one, wait_for, sync_blockheight, TIMEOUT,
     expected_peer_features, expected_node_features,
     expected_channel_features,
-    check_coin_moves, first_channel_id, account_balance
+    check_coin_moves, first_channel_id, account_balance, basic_fee
 )
 from bitcoin.core import CMutableTransaction, CMutableTxOut
 
@@ -163,7 +163,7 @@ def test_opening_tiny_channel(node_factory):
     #
     dustlimit = 546
     reserves = 2 * dustlimit
-    min_commit_tx_fees = 5430
+    min_commit_tx_fees = basic_fee(7500)
     min_for_opener = min_commit_tx_fees + dustlimit + 1
 
     l1_min_capacity = 1000            # 1k old default, too small but used at l1 to allow small incoming channels

tests/test_misc.py

@@ -2402,7 +2402,7 @@ def test_listtransactions(node_factory):
     """Sanity check for the listtransactions RPC command"""
     l1, l2 = node_factory.get_nodes(2, opts=[{}, {}])
 
-    wallettxid = l1.openchannel(l2, 10**4)["wallettxid"]
+    wallettxid = l1.openchannel(l2, 10**5)["wallettxid"]
     txids = [i["txid"] for tx in l1.rpc.listtransactions()["transactions"]
              for i in tx["inputs"]]
     # The txid of the transaction funding the channel is present, and

tests/test_pay.py

@@ -1363,7 +1363,7 @@ def test_forward_local_failed_stats(node_factory, bitcoind, executor):
     c12 = l1.fund_channel(l2, 10**6)
     c23 = l2.fund_channel(l3, 10**6)
     c24 = l2.fund_channel(l4, 10**6)
-    c25 = l2.fund_channel(l5, 10**4)
+    c25 = l2.fund_channel(l5, 10**4 * 2)
     l6.fund_channel(l1, 10**6)
 
     # Make sure routes finalized.

tests/test_plugin.py

@@ -1211,9 +1211,9 @@ def test_bcli(node_factory, bitcoind, chainparams):
 
     l1.fundwallet(10**5)
     l1.connect(l2)
-    fc = l1.rpc.fundchannel(l2.info["id"], 10**4)
+    fc = l1.rpc.fundchannel(l2.info["id"], 10**4 * 2)
     txo = l1.rpc.call("getutxout", {"txid": fc['txid'], "vout": fc['outnum']})
-    assert (Millisatoshi(txo["amount"]) == Millisatoshi(10**4 * 10**3)
+    assert (Millisatoshi(txo["amount"]) == Millisatoshi(10**4 * 2 * 10**3)
             and txo["script"].startswith("0020"))
     l1.rpc.close(l2.info["id"])
     # When output is spent, it should give us null !

tests/utils.py

@@ -102,3 +102,12 @@ def account_balance(n, account_id):
 
 def first_channel_id(n1, n2):
     return only_one(only_one(n1.rpc.listpeers(n2.info['id'])['peers'])['channels'])['channel_id']
+
+
+def basic_fee(feerate):
+    if False:  # FIXME-anchor
+        # option_anchor_outputs
+        weight = 1124
+    else:
+        weight = 724
+    return (weight * feerate) // 1000