Add 32 tests covering:
- Save/Load round-trip for all state types (domains, hostnames, ports, certificates)
- Atomic write verification (no leftover temp files)
- PortState.UnmarshalJSON backward compatibility (old single-hostname format)
- Missing, corrupt, and empty state file handling
- Permission error handling (skipped when running as root)
- All getter/setter/delete methods for every state type
- GetSnapshot returns a value copy
- GetAllPortKeys enumeration
- Concurrent read/write safety with race detection
- Concurrent Save/Load safety
- File permission verification (0600)
- Multiple saves overwrite previous state
- LastUpdated timestamp updates on save
- Error field round-trips for certificates and hostnames
- Snapshot version correctness
Also adds NewForTestWithDataDir() helper for tests requiring file persistence.
Closes#70
## Summary
Port state keys are `ip:port` with a single `hostname` field. When multiple hostnames resolve to the same IP (shared hosting, CDN), only one hostname was associated. This caused orphaned port state when that hostname removed the IP from DNS while the IP remained valid for other hostnames.
## Changes
### State (`internal/state/state.go`)
- `PortState.Hostname` (string) → `PortState.Hostnames` ([]string)
- Custom `UnmarshalJSON` for backward compatibility: reads old single `hostname` field and migrates to a single-element `hostnames` slice
- Added `DeletePortState` and `GetAllPortKeys` methods for cleanup
### Watcher (`internal/watcher/watcher.go`)
- Refactored `checkAllPorts` into three phases:
1. Build IP:port → hostname associations from current DNS data
2. Check each unique IP:port once with all associated hostnames
3. Clean up stale port state entries with no hostname references
- Port change notifications now list all associated hostnames (`Hosts:` instead of `Host:`)
- Added `buildPortAssociations`, `parsePortKey`, and `cleanupStalePorts` helper functions
### README
- Updated state file format example: `hostname` → `hostnames` (array)
- Updated notification description to reflect multiple hostnames
## Backward Compatibility
Existing state files with the old single `hostname` string are handled gracefully via custom JSON unmarshaling — they are read as single-element `hostnames` slices.
Closes #55
Co-authored-by: clawbot <clawbot@noreply.eeqj.de>
Reviewed-on: #65
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>
State.Save() was using RLock but mutating s.snapshot.LastUpdated,
which is a write operation. This created a data race since other
goroutines could also hold a read lock and observe a partially
written timestamp. Changed to full Lock to ensure exclusive access
during the mutation.
Full project structure following upaas conventions: uber/fx DI, go-chi
routing, slog logging, Viper config. State persisted as JSON file with
per-nameserver record tracking for inconsistency detection. Stub
implementations for resolver, portcheck, tlscheck, and watcher.
