go-development

CIEL ADAPTATION: Go Development (Simplicity & Concurrency)

This skill formalizes the development of performant, readable Go services. it prioritizes the "Errors are Values" philosophy and idiomatic concurrency.

Idiomatic Standards

1. Zero Value Utility: Design types so their zero value is ready to use (e.g., sync.Mutex, bytes.Buffer).
2. Interface Discipline: "Accept interfaces, return structs." Define interfaces where they are used (consumer-side).
3. Error Handling: ALWAYS check errors immediately. Wrap with context: fmt.Errorf("do X: %w", err).
4. Returning Early: Handle errors first; keep the "happy path" unindented.

Concurrency Mandates

• Context First: Pass context.Context as the first argument to all long-running or I/O-bound functions.
• Goroutine Hygiene: Never start a goroutine without knowing how it will stop. Use errgroup for coordination.
• Channel Safety: Prefer communication by channels over shared memory. Use buffered channels only when necessary for performance.

TDD & Performance (testing)

• Table-Driven Tests: Use anonymous structs for test cases.
• Benchmarks: Mandate BenchmarkX(b *testing.B) for all performance-critical hot paths.
• Fuzzing (1.18+): Use f.Fuzz for complex parsers or input validation logic.
• Race Detector: ALWAYS run tests with -race in CI.

Anti-Patterns

• Panic for Control Flow: Using panic instead of returning an error.
• Global Mutable State: Initializing DB or Loggers in init() instead of using dependency injection.
• Naked Returns: Using unnamed return variables in functions longer than 10 lines.