Go Development (1.25+)

Core Principles

• Stdlib first: External deps only when justified

• Concrete types: Define interfaces at consumer, return structs

• Composition: Over inheritance, always

• Fail fast: Clear errors with context

• Simple: The obvious solution is usually correct

Quick Patterns

Error Handling

if err := doThing(); err != nil { return fmt.Errorf("do thing: %w", err) }

Struct with Options

type Server struct { addr string timeout time.Duration }

func NewServer(addr string, opts ...Option) *Server { s := &Server{addr: addr, timeout: 30 * time.Second} for _, opt := range opts { opt(s) } return s }

Table-Driven Tests

tests := []struct { name string input string want string wantErr bool }{ {"valid", "hello", "HELLO", false}, {"empty", "", "", true}, } for _, tt := range tests { t.Run(tt.name, func(t *testing.T) { got, err := Process(tt.input) if tt.wantErr { require.Error(t, err) return } require.NoError(t, err) assert.Equal(t, tt.want, got) }) }

Go 1.25 Features

• testing/synctest: Deterministic concurrent testing with simulated clock

• encoding/json/v2: Experimental, 3-10x faster (GOEXPERIMENT=jsonv2)

• runtime/trace.FlightRecorder: Production trace capture on-demand

• Container-aware GOMAXPROCS: Auto-detects cgroup limits

• GreenTea GC: Experimental, lower latency (GOEXPERIMENT=greenteagc)

References

• PATTERNS.md - Detailed code patterns

• TESTING.md - Testing strategies with testify/mockery

• CLI.md - CLI application patterns

Tooling

go build ./... # Build go test -race ./... # Test with race detector golangci-lint run # Lint mockery --all # Generate mocks