ln-e2e-test: wait for both CLN nodes to reach the chain tip before the hold receive

Run right after tests that mine, cln-ark could trail by a block or two and
the receive failed with final_incorrect_cltv_expiry.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 5 insertions, 0 deletions

diff --git a/tools/ark/ln-e2e-test.js b/tools/ark/ln-e2e-test.js
index 088dcb0..f4b5856 100644
--- a/tools/ark/ln-e2e-test.js
+++ b/tools/ark/ln-e2e-test.js
@@ -99,6 +99,11 @@ check('alice +100 from tiny send', aliceAfter === aliceBefore + 100, `${aliceBef
 
 // ---------------------------------------------------------------------------
 console.log('\n[2] RECEIVE: clc pays a 4000-sat invoice minted by hal (hold flow)');
+// both CLN nodes must have caught up with blocks earlier tests mined, or the
+// HTLC's cltv disagrees with the hold invoice (final_incorrect_cltv_expiry)
+const tip = Number(sh('docker exec bc bitcoin-cli getblockcount'));
+const synced = (node) => JSON.parse(sh(`docker exec ${node} lightning-cli --regtest getinfo`)).blockheight >= tip;
+for (let i = 0; i < 40 && !(synced('clc') && synced('cln-ark')); i++) await sleep(500);
 const balBefore = mgr.balance().spendableSat;
 const recv = await mgr.createLnInvoice(4000, 'ark-e2e-receive');
 console.log('   hal invoice:', recv.invoice.slice(0, 50) + '…');