nim-chat-poc/cleanup/03-unused.md

Cleanup 03 — Unused code (post-squash re-pass, 2026-05-28)

The prior 03-unused.md in this file reflected a pre-squash session whose SHAs (a3826a65, 0b2a5398, 286cce8) no longer exist on the current branches. Those removals (confirmMembershipLeafIndex, RegisterMemberFunc + slot wiring) are nonetheless absorbed into the squashed feature commits — rg for those symbols returns 0 hits anywhere in the in-scope trees. This pass re-audits the post-squash state.

Research notes

Ran nim check --hints:on --warnings:on on every in-scope nwaku file plus the outer chat sources. Filtered hints/warnings to in-scope files only (upstream-file warnings ignored). Cross-checked candidate removals with rg across all five repos.

True positives

Symbol / Import	File	Verdict
proc hexToBytes32LE	vendor/nwaku/waku/waku_mix/logos_core_client.nim:310	UNUSED — zero callers anywhere. Sole consumer (LE path) was replaced by hexToBytes32 + caller-side reversal during the migration.
import std/algorithm	same file	UNUSED — reverse only referenced by the dead hexToBytes32LE.
import std/sequtils	vendor/nwaku/waku/waku_mix/protocol.nim:3	UNUSED — no mapIt/filterIt/toSeq left in module.
import waku_peer_store	vendor/nwaku/waku/waku_mix/protocol.nim:21	UNUSED — WakuPeerStore not referenced.
import ../waku_core/topics/sharding	vendor/nwaku/waku/node/waku_mix_coordination.nim:10	UNUSED — RelayShard/ShardId not referenced.
Duplicate kademliaDiscoveryConf.with* block	vendor/nwaku/tools/confutils/cli_args.nim:1192-1193	DEAD-CODE BUG — identical 2-line block appears earlier (lines 1168-1169). Both run on every toWakuConf call; second one is purely redundant. Introduced by our squash.

False positives investigated and rejected

• hexToBytes32LE-style — none others.
• import std/sequtils in waku_kademlia.nim flagged by nim check, but mapIt is actually used at line 126; build fails without it. Reverted.
• extractMixPubKey in waku_kademlia.nim flagged unused but invoked from same file in async closure context (mixPubKey = extractMixPubKey(service)). Hint is wrong.
• req in gifter/client.nim queryMembershipStatus flagged unused but its .encode() is awaited in connection.writeLP(req.encode().buffer). Hint is wrong.
• Candidates from task brief that turned out to be live and load-bearing:
  • tools/confutils/cli_args.nim — used by wakunode2, liblogosdelivery, chat2mix, and several tests. Only the duplicate-line dead block was cut.
  • apps/chat2mix/* — still wired via Makefile (chat2mix: target), waku.nimble (task chat2mix), and downstream vendor/logos-lez-rln/build_all.sh (make chat2mix). Replacing it with the chat-module + logoscore stack is a larger refactor and out of scope for an unused-code pass.
  • simulations/mixnet/* — older bare-mix sim, referenced by README only; not invoked by simulations/mix_lez_chat/run_simulation.sh. Removing would orphan apps/chat2mix too. Deferred along with chat2mix.
  • tests/waku_rln_relay/test_rln_gifter.nim — included in tests/waku_rln_relay/test_all.nim. Live.
• Rust: cargo build on lez-rln/ workspace produced zero unused warnings.
• C++: chat-module and delivery-module sources are minimal; no obviously dead exports surfaced.

Critical assessment

The squash already absorbed the prior session's bigger removals (confirmMembershipLeafIndex, RegisterMemberFunc). What remained was a handful of stale imports and one defensive dup that snuck through during the gifter wiring. All five surviving items are mechanical and safe — none touch FFI exports or cross-repo symbols.

Applied

In vendor/nwaku (mirrored to both logos-delivery checkouts):

• waku/waku_mix/logos_core_client.nim: remove proc hexToBytes32LE (9 lines) + drop algorithm from std import.
• waku/waku_mix/protocol.nim: drop sequtils from std import, drop waku_peer_store import.
• waku/node/waku_mix_coordination.nim: drop ../waku_core/topics/sharding import.
• tools/confutils/cli_args.nim: remove the duplicate kademliaDiscoveryConf.withEnabled / withBootstrapNodes pair at end of toWakuConf.

Net: −15 lines per repo × 3 mirrors. Builds clean: liblogoschat ✓, liblogosdelivery ✓.

Commit SHAs

• vendor/nwaku (feat/sim-rln-gifter-auth): 1353d42d
• vendor/logos-lez-rln/logos-delivery (feat/sim-rln-gifter-auth-debug, loose): 574cd9a7
• vendor/logos-lez-rln/logos-delivery-module/vendor/logos-delivery (feat/sim-rln-gifter-auth-debug, canonical): 227dd67f
• outer logos-chat / lez-rln / delivery-module / chat-module / mix-rln plugin: no source changes this pass.

Deferred

• apps/chat2mix/ + simulations/mixnet/ — superseded by the chat-module + logoscore stack used in simulations/mix_lez_chat/, but still wired into Make targets and the lez-rln build_all.sh. Removal is a multi-repo refactor (Makefile, waku.nimble, build scripts), not an unused-code edit. Worth a dedicated pass.
• liblogos_rln_module_api.h triplicate — flagged by agent 02 as a build-infra issue; same triplication still present but not under "unused code".
• Several XDeclaredButNotUsed hints inside async procs (req, extractMixPubKey) are nim-check false positives caused by closure transformation. Left as-is.

Sim result

(filled in after the run completes below)