Go Best Practices

Pattern	When to apply
Minimal main	New binaries
Single bootstrap	App wiring across modes
Ordered shutdown	Long-running processes
Non-blocking fanout	Channel-based event systems
Concurrency testing	Any goroutine code
Layered config	Multi-source configuration
Cross-platform paths	File/config path resolution
Secure debug logging	HTTP client instrumentation
Golden test matrices	Rendering / output components
Focused linters	CI pipeline setup

Read references/patterns.md for code examples.

Rules

1. main.go is a stub. Call cmd.Execute() and nothing else. Gate diagnostics (pprof) behind env vars.

2. One bootstrap path. All modes (interactive, headless, test) share the same initialization function. Two paths will drift.

3. Ordered shutdown. Cancel dependents before their dependencies, then run independent cleanup in parallel under a timeout context. WaitGroup the parallel phase.

4. Never block the sender. Non-blocking channel sends with an explicit drop policy. Log drops at debug level. Document the policy.

5. Test concurrency mechanically. testing/synctest for deterministic timing, goleak.VerifyNone for leak detection, dedicated regression tests for timer/channel deadlocks.

6. Explicit config precedence. Global → project → flags. Walk up from CWD to discover project configs, reverse so closest wins, deep-merge.

7. Centralize platform paths. One function per concern. Resolution order: env override → XDG → platform default → fallback.

8. Redact secrets in debug logs. Wrap http.RoundTripper. Filter headers matching authorization, api-key, token, secret. Gate on debug level to skip allocation in prod.

9. Golden tests over matrices. Cross dimensions (layout × theme × size) as parallel subtests. Sweep continuous ranges to catch off-by-one bugs.