- handle_call(:shutdown, _, state): split into a shutting_down=true
fast-path clause and a normal initiate_shutdown clause. No more
`if state.shutting_down` inside the callback body.
- terminate/2: extract graceful_shutdown_needed?/1 (four function
heads on the reason tag) and maybe_graceful_drain/2 (guarded on
state.shutting_down) so the shutdown side-effects are isolated to
a single, pattern-matched entry point.
Adds 4 unit tests for the pure callback paths
(shutting_down?, shutdown-already-in-progress, EXIT pass-through,
rescue fallback on unavailable GenServer).
Turned on :error_handling, :underspecs, and :unmatched_returns in
mix.exs dialyzer config. The 97 warnings this surfaced were fixed in
place rather than suppressed:
- unmatched_return (79): explicit discard with `_ = ...` for
fire-and-forget side effects (Process.cancel_timer, :ets.new,
send/2), and pattern-matched `:ok = ...` for control-plane
Phoenix.PubSub subscribe/unsubscribe/broadcast calls so a future
return-shape change fails loud.
- contract_supertype (18): tightened @spec arg and return types on
data_builder, historical_loader, url_params, packet_utils,
encoding_utils, aprs_symbol, weather_controller, packet_replay to
match each function's actual success typing.
No behavioural change. mix compile clean, 1008 tests pass, dialyzer
count is now 0.
Delete 5 unused modules: Presence (untracked), LiveView ShutdownHandler
(unused mixin), RateLimiterWrapper (pointless delegation), Passcode
(only used by own test), MapLive.Utils (pure delegates).
Fix ShutdownHandler to not call deleted Presence. Inline ParamUtils
at call sites. Remove cachex dep and 27 stale entries from mix.lock.
Clean commented-out Exq/Redis config from application.ex.
- Add SKIP_DB_CREATE env var to skip database creation when using PgBouncer
- Fix redis_children() to return proper child specs
- Implement zero-downtime graceful shutdown without user notifications
- Add health check plug for Kubernetes probes
- Remove user-facing shutdown notifications for seamless deployments
Co-Authored-By: Claude <noreply@anthropic.com>
