f avoid magic

Author: TheBlueMatt

lightning/src/ln/functional_tests.rs

@@ -1506,15 +1506,15 @@ fn test_chan_init_feerate_unaffordability() {
 	// Test that we will reject channel opens which do not leave enough to pay for any HTLCs due to
 	// channel reserve and feerate requirements.
 	let mut chanmon_cfgs = create_chanmon_cfgs(2);
+	let feerate_per_kw = *chanmon_cfgs[0].fee_estimator.sat_per_kw.lock().unwrap();
 	let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
 	let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 	let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 
 	// Set the push_msat amount such that nodes[0] will not be able to afford to add even a single
 	// HTLC.
-	let feerate_per_kw = 253;
 	let mut push_amt = 100_000_000;
-	push_amt -= commit_tx_fee_msat(feerate_per_kw, 4);
+	push_amt -= commit_tx_fee_msat(feerate_per_kw, MIN_AFFORDABLE_HTLC_COUNT as u64);
 	assert_eq!(nodes[0].node.create_channel(nodes[1].node.get_our_node_id(), 100_000, push_amt + 1, 42, None).unwrap_err(),
 		APIError::APIMisuseError { err: "Funding amount (356) can't even pay fee for initial commitment transaction fee of 357.".to_string() });