Function test_setchannel_zero

tests/test_pay.py:2384–2430

(node_factory, bitcoind)

def test_setchannel_zero(node_factory, bitcoind):
    # TEST SETUP
    #
    # [l1] <--default_fees--> [l2] <--specific_fees--> [l3]
    #
    # - json listchannels is able to see the new values in foreign node
    # - routing calculates fees correctly
    # - payment can be done using zero fees
    DEF_BASE = 1
    DEF_PPM = 10
    MAX_HTLC = Millisatoshi(int(FUNDAMOUNT * 1000 * 0.99))

    l1, l2, l3 = node_factory.line_graph(
        3, announce_channels=True, wait_for_announce=True,
        opts={'fee-base': DEF_BASE, 'fee-per-satoshi': DEF_PPM})

    # get short channel id for 2->3
    scid = l2.get_channel_scid(l3)

    # TEST ZERO fees possible
    l2.rpc.setchannel(scid, 0, 0)
    wait_for(lambda: [c['base_fee_millisatoshi'] for c in l1.rpc.listchannels(scid)['channels']] == [0, DEF_BASE])
    wait_for(lambda: [c['fee_per_millionth'] for c in l1.rpc.listchannels(scid)['channels']] == [0, DEF_PPM])

    # test if zero fees are applied
    route = l1.single_route(l3.info['id'], 4999999)
    assert len(route) == 2
    assert route[0]['amount_out_msat'] == 4999999
    assert route[1]['amount_out_msat'] == 4999999

    # Wait for l3 to know about our low-balling, otherwise they'll add a wrong
    # routehint to the invoice.
    wait_for(lambda: [(c['base_fee_millisatoshi'], c['fee_per_millionth'], c['active']) for c in l3.rpc.listchannels(scid)['channels']] == [(0, 0, True), (DEF_BASE, DEF_PPM, True)])

    # do and check actual payment
    inv = l3.rpc.invoice(4999999, 'test_setchannel_3', 'desc')['bolt11']
    result = l1.dev_pay(inv, dev_use_shadow=False)
    assert result['status'] == 'complete'
    assert result['amount_sent_msat'] == 4999999

    # FIXME: hack something up to advertize min_htlc > 0, then test mintoolow.
    with pytest.raises(RpcError, match="htlcmax cannot be less than htlcmin"):
        l2.rpc.setchannel(scid, htlcmin=100000, htlcmax=99999)

    ret = l2.rpc.setchannel(scid, htlcmax=FUNDAMOUNT * 1000)
    assert 'warning_htlcmax_too_high' in only_one(ret['channels'])
    assert only_one(ret['channels'])['maximum_htlc_out_msat'] == MAX_HTLC


def test_setchannel_restart(node_factory, bitcoind):