Public commit record
98/100 · Strong
What the developer wrote
Authored by Bastien Teinturier
Fix balance fuzz tests (#3251)
Those tests started randomly failing after moving to anchor outputs.
The reason is that anchor outputs have a bigger commit weight than non
anchor channels, and with our initial balance allocation we sometimes
reached a point where the *remote* had exhausted all of its balance to
pay commit fees (when the feerate was around 10 000 sat/kw), so the
*local* couldn't send HTLCs (`RemoteCannotAffordFeesForNewHtlc`). This
is an expected situation where we cannot do anything except wait for
pending HTLCs to resolve before sending other HTLCs.
We simply increase the initial balance to avoid running into this case.
We also remove the `skip` case (which wasn't working at all, we should
have used the `cancel` scalatest helper if we wanted to interrupt the
test without failing it) and allow failures during the initial HTLC
setup (which can happen if HTLCs are larger than the available balance).
✓ Descriptive subject✓ Names a concrete action or component✓ Provides detailed explanatory context✓ Explains rationale or failure mode✓ Mentions testing or verification✓ Links an issue, advisory, or supporting reference
What changed, and why it matters
This commit only changes test code. It fixes flaky balance fuzz tests in Eclair by giving simulated channels more starting money so they can afford higher transaction fees under anchor outputs. There is no change to production code, no real-world security fix, and no vulnerability being patched.
Recommended action
No security action required. Treat as a routine test-maintenance commit.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The diff modifies CommitmentsSpec.scala, a unit test file. It increases the initial toLocal/toRemote balance multiplier from 10 to 15 times the max pending HTLC amount and replaces the ScalaTest ignore/skip helper with a silent comment. The goal is to avoid test failures caused by anchor outputs increasing commitment transaction weight, which can exhaust the remote balance for fees at high feerates. No production channel logic is altered.
Changed components
eclair-core/src/test/scala/fr/acinq/eclair/channel/CommitmentsSpec.scalaInspect captured patch +12 / −12
diff --git a/eclair-core/src/test/scala/fr/acinq/eclair/channel/CommitmentsSpec.scala b/eclair-core/src/test/scala/fr/acinq/eclair/channel/CommitmentsSpec.scala
index 6b03a0a..c314d28 100644
--- a/eclair-core/src/test/scala/fr/acinq/eclair/channel/CommitmentsSpec.scala
+++ b/eclair-core/src/test/scala/fr/acinq/eclair/channel/CommitmentsSpec.scala
@@ -415,17 +415,17 @@ class CommitmentsSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with
}
test("should always be able to send availableForSend", Tag("fuzzy")) { f =>
- val maxPendingHtlcAmount = 1000000.msat
+ val maxPendingHtlcAmount = 1_000_000.msat
case class FuzzTest(isInitiator: Boolean, pendingHtlcs: Int, feeRatePerKw: FeeratePerKw, dustLimit: Satoshi, toLocal: MilliSatoshi, toRemote: MilliSatoshi)
for (_ <- 1 to 100) {
val t = FuzzTest(
isInitiator = Random.nextInt(2) == 0,
pendingHtlcs = Random.nextInt(10),
- feeRatePerKw = FeeratePerKw(Random.nextInt(10000).max(1).sat),
+ feeRatePerKw = FeeratePerKw(Random.nextInt(10_000).max(1).sat),
dustLimit = Random.nextInt(1000).sat,
- // We make sure both sides have enough to send/receive at least the initial pending HTLCs.
- toLocal = maxPendingHtlcAmount * 2 * 10 + Random.nextInt(1000000000).msat,
- toRemote = maxPendingHtlcAmount * 2 * 10 + Random.nextInt(1000000000).msat)
+ // We make sure both sides have enough to send/receive at least the initial pending HTLCs while paying the commit fees.
+ toLocal = maxPendingHtlcAmount * 2 * 15 + Random.nextInt(1_000_000_000).msat,
+ toRemote = maxPendingHtlcAmount * 2 * 15 + Random.nextInt(1_000_000_000).msat)
var c = CommitmentsSpec.makeCommitments(t.toLocal, t.toRemote, t.feeRatePerKw, t.dustLimit, t.isInitiator)
// Add some initial HTLCs to the pending list (bigger commit tx).
for (_ <- 1 to t.pendingHtlcs) {
@@ -433,7 +433,7 @@ class CommitmentsSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with
val (_, cmdAdd) = makeCmdAdd(amount, randomKey().publicKey, f.currentBlockHeight)
c.sendAdd(cmdAdd, f.currentBlockHeight, TestConstants.Alice.nodeParams.channelConf, feeConfNoMismatch) match {
case Right((cc, _)) => c = cc
- case Left(e) => ignore(s"$t -> could not setup initial htlcs: $e")
+ case Left(e) => // we ignore failures (the HTLC amount probably exceeded availableBalanceForSend)
}
}
if (c.availableBalanceForSend > 0.msat) {
@@ -445,17 +445,17 @@ class CommitmentsSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with
}
test("should always be able to receive availableForReceive", Tag("fuzzy")) { f =>
- val maxPendingHtlcAmount = 1000000.msat
+ val maxPendingHtlcAmount = 1_000_000.msat
case class FuzzTest(isInitiator: Boolean, pendingHtlcs: Int, feeRatePerKw: FeeratePerKw, dustLimit: Satoshi, toLocal: MilliSatoshi, toRemote: MilliSatoshi)
for (_ <- 1 to 100) {
val t = FuzzTest(
isInitiator = Random.nextInt(2) == 0,
pendingHtlcs = Random.nextInt(10),
- feeRatePerKw = FeeratePerKw(Random.nextInt(10000).max(1).sat),
+ feeRatePerKw = FeeratePerKw(Random.nextInt(10_000).max(1).sat),
dustLimit = Random.nextInt(1000).sat,
- // We make sure both sides have enough to send/receive at least the initial pending HTLCs.
- toLocal = maxPendingHtlcAmount * 2 * 10 + Random.nextInt(1000000000).msat,
- toRemote = maxPendingHtlcAmount * 2 * 10 + Random.nextInt(1000000000).msat)
+ // We make sure both sides have enough to send/receive at least the initial pending HTLCs while paying the commit fees.
+ toLocal = maxPendingHtlcAmount * 2 * 15 + Random.nextInt(1_000_000_000).msat,
+ toRemote = maxPendingHtlcAmount * 2 * 15 + Random.nextInt(1_000_000_000).msat)
var c = CommitmentsSpec.makeCommitments(t.toLocal, t.toRemote, t.feeRatePerKw, t.dustLimit, t.isInitiator)
// Add some initial HTLCs to the pending list (bigger commit tx).
for (_ <- 1 to t.pendingHtlcs) {
@@ -463,7 +463,7 @@ class CommitmentsSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with
val add = UpdateAddHtlc(randomBytes32(), c.changes.remoteNextHtlcId, amount, randomBytes32(), CltvExpiry(f.currentBlockHeight), TestConstants.emptyOnionPacket, None, accountable = false, None)
c.receiveAdd(add) match {
case Right(cc) => c = cc
- case Left(e) => ignore(s"$t -> could not setup initial htlcs: $e")
+ case Left(e) => // we ignore failures (the HTLC amount probably exceeded availableBalanceForReceive)
}
}
if (c.availableBalanceForReceive > 0.msat) {
Risk score
Our methodology →Why this scored 15/100
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