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.
- Fix leader election guard test for :undefined pid
- Fix cpu_sup.util() pattern matching to handle numeric return
- Fix encoding_utils to always return explicit nil when needed
- Remove unused finite_float? function
- Fix signal handler to match :ok return from :os.set_signal/2
- Remove redundant catch-all pattern in database metrics
- Fix Gridsquare pattern matching in info_live template
- Remove unnecessary nil check for calculate_course result
- Fix get_packet_received_at to not check for nil (always returns DateTime)
- Remove redundant catch-all pattern in weather format_weather_value
- Fix query builder to use from(p in Packet) instead of bare Packet atom
Reduced dialyzer errors from 49 to 6. Remaining warnings are mostly
false positives from template compilation and overloaded function specs.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
