The protection feature promises top-N per inbound/dialed pool, but
every existing test constructed peers via p2p.NewPeer (which produces
no-flag peers), so all test peers landed in the dialed pool and the
per-pool split was never validated.
Extract the selection logic from protectedPeers into a pure helper
protectedPeersByPool(inbound, dialed, stats) that accepts pre-split
pools. This sidesteps the unexported p2p.connFlag types and makes the
interesting behavior directly testable. Add three tests covering:
- exact top-N selected independently in each pool
- cross-category union with overlap deduplication
- per-pool independence: top dialed peers stay protected even when
every inbound peer scores higher globally
Compute the protected peer set once in dropRandomPeer via
protectedPeers(), then include protection as a condition in
selectDoNotDrop alongside trusted/static/recent checks. This
eliminates the separate filterProtectedPeers post-pass and the
awkward "all protected → skip" branch.
Rename filterProtectedPeers to protectedPeers, returning
map[*p2p.Peer]bool instead of filtering a slice. The map is
checked directly in selectDoNotDrop via protected[p].
protectTopN used maxPeers (configured capacity) to compute the
number of peers to protect. With small droppable sets this could
protect everyone, permanently disabling churn.
Use len(entries) (current droppable count in each category) instead.
With 20 droppable dialed peers and 10% fraction, 2 are protected.
With 3 droppable peers, 0 are protected — churn is never blocked.
txtracker tests (7 tests):
- NotifyReceived: stats empty before chain events
- InclusionEMA: EMA increases on inclusion, decays on empty blocks
- Finalization: Finalized counter credited after finalization
- MultiplePeers: each peer credited for own txs only
- FirstDelivererWins: duplicate delivery ignored
- NoFinalizationCredit: no credit without finalization
- EMADecay: EMA approaches zero after 30 empty blocks
dropper tests (6 tests):
- FilterProtectedNoStats: nil stats → all droppable
- FilterProtectedEmptyStats: empty map → all droppable
- FilterProtectedTopPeer: top-scored peers removed from droppable
- FilterProtectedZeroScore: zero scores → no protection
- FilterProtectedOverlap: peer top in both categories → counted once
- FilterProtectedAllProtected: all droppable protected → empty list
Also fix: create peer entries during EMA update for peers with
inclusions in the current block (previously only created during
finalization, so EMA was not tracked before first finalization).
