plugins/rebalance/test_rebalance.py

import os
from pyln.testing.fixtures import *  # noqa: F401,F403
from pyln.client import Millisatoshi

plugin_path = os.path.join(os.path.dirname(__file__), "rebalance.py")
plugin_opt = {'plugin': plugin_path}


# waits for a bunch of nodes HTLCs to settle
def wait_for_all_htlcs(nodes):
    for n in nodes:
        n.wait_for_htlcs()


# waits for all nodes to have all scids gossip active
def wait_for_all_active(nodes, scids):
    for n in nodes:
        for scid in scids:
            n.wait_channel_active(scid)


def test_rebalance_starts(node_factory):
    l1 = node_factory.get_node()
    # Test dynamically
    l1.rpc.plugin_start(plugin_path)
    l1.rpc.plugin_stop(plugin_path)
    l1.rpc.plugin_start(plugin_path)
    l1.stop()
    # Then statically
    l1.daemon.opts["plugin"] = plugin_path
    l1.start()


def test_rebalance_manual(node_factory, bitcoind):
    l1, l2, l3 = node_factory.line_graph(3, opts=plugin_opt)
    nodes = [l1, l2, l3]

    # form a circle so we can do rebalancing
    l3.connect(l1)
    l3.fundchannel(l1)

    # get scids
    scid12 = l1.get_channel_scid(l2)
    scid23 = l2.get_channel_scid(l3)
    scid31 = l3.get_channel_scid(l1)
    scids = [scid12, scid23, scid31]

    # wait for each others gossip
    bitcoind.generate_block(6)
    for n in nodes:
        for scid in scids:
            n.wait_channel_active(scid)

    # check we can do an auto amount rebalance
    result = l1.rpc.rebalance(scid12, scid31)
    print(result)
    assert result['status'] == 'complete'
    assert result['outgoing_scid'] == scid12
    assert result['incoming_scid'] == scid31
    assert result['hops'] == 3
    assert result['received'] == '500000000msat'

    # wait until listpeers is up2date
    wait_for_all_htlcs(nodes)

    # check that channels are now balanced
    c12 = l1.rpc.listpeerchannels(l2.info['id'])['channels'][0]
    c13 = l1.rpc.listpeerchannels(l3.info['id'])['channels'][0]
    assert abs(0.5 - (Millisatoshi(c12['to_us_msat']) / Millisatoshi(c12['total_msat']))) < 0.01
    assert abs(0.5 - (Millisatoshi(c13['to_us_msat']) / Millisatoshi(c13['total_msat']))) < 0.01

    # check we can do a manual amount rebalance in the other direction
    result = l1.rpc.rebalance(scid31, scid12, '250000000msat')
    assert result['status'] == 'complete'
    assert result['outgoing_scid'] == scid31
    assert result['incoming_scid'] == scid12
    assert result['hops'] == 3
    assert result['received'] == '250000000msat'

    # briefly check rebalancereport works
    report = l1.rpc.rebalancereport()
    assert report.get('rebalanceall_is_running') is False
    assert report.get('total_successful_rebalances') == 2


def test_rebalance_all(node_factory, bitcoind):
    l1, l2, l3 = node_factory.line_graph(3, opts=plugin_opt)
    nodes = [l1, l2, l3]

    # check we get an error if theres just one channel
    result = l1.rpc.rebalanceall()
    assert result['message'] == 'Error: Not enough open channels to rebalance anything'

    # now we add another 100% outgoing liquidity to l1 which does not help
    l4 = node_factory.get_node()
    l1.connect(l4)
    l1.fundchannel(l4)

    # test this is still not possible
    result = l1.rpc.rebalanceall()
    assert result['message'] == 'Error: Not enough liquidity to rebalance anything'

    # remove l4 it does not distort further testing
    l1.rpc.close(l1.get_channel_scid(l4))

    # now we form a circle so we can do actually rebalanceall
    l3.connect(l1)
    l3.fundchannel(l1)

    # get scids
    scid12 = l1.get_channel_scid(l2)
    scid23 = l2.get_channel_scid(l3)
    scid31 = l3.get_channel_scid(l1)
    scids = [scid12, scid23, scid31]

    # wait for each others gossip
    bitcoind.generate_block(6)
    wait_for_all_active(nodes, scids)

    # check that theres nothing to stop when theres nothing to stop
    result = l1.rpc.rebalancestop()
    assert result['message'] == "No rebalance is running, nothing to stop."

    # check the rebalanceall starts
    result = l1.rpc.rebalanceall(feeratio=5.0)  # we need high fees to work
    assert result['message'].startswith('Rebalance started')
    l1.daemon.wait_for_logs([f"tries to rebalance: {scid12} -> {scid31}",
                             f"Automatic rebalance finished"])

    # check additional calls to stop return 'nothing to stop' + last message
    result = l1.rpc.rebalancestop()['message']
    assert result.startswith("No rebalance is running, nothing to stop. "
                             "Last 'rebalanceall' gave: Automatic rebalance finished")

    # wait until listpeers is up2date
    wait_for_all_htlcs(nodes)

    # check that channels are now balanced
    c12 = l1.rpc.listpeerchannels(l2.info['id'])['channels'][0]
    c13 = l1.rpc.listpeerchannels(l3.info['id'])['channels'][0]
    assert abs(0.5 - (Millisatoshi(c12['to_us_msat']) / Millisatoshi(c12['total_msat']))) < 0.01
    assert abs(0.5 - (Millisatoshi(c13['to_us_msat']) / Millisatoshi(c13['total_msat']))) < 0.01

    # briefly check rebalancereport works
    report = l1.rpc.rebalancereport()
    assert report.get('rebalanceall_is_running') is False
    assert report.get('total_successful_rebalances') == 2