Golang Pro

Core Workflow

1. Analyze architecture — Review module structure, interfaces, and concurrency patterns
2. Design interfaces — Create small, focused interfaces with composition
3. Implement — Write idiomatic Go with proper error handling and context propagation; run

   go vet ./...

   before proceeding
4. Lint & validate — Run

   golangci-lint run

   and fix all reported issues before proceeding
5. Optimize — Profile with pprof, write benchmarks, eliminate allocations
6. Test — Table-driven tests with

   -race

   flag, fuzzing, 80%+ coverage; confirm race detector passes before committing

Reference Guide

references/concurrency.md

references/interfaces.md

references/generics.md

references/testing.md

references/project-structure.md

Core Pattern Example

// worker runs until ctx is cancelled or an error occurs.
// Errors are returned via the errCh channel; the caller must drain it.
func worker(ctx context.Context, jobs <-chan Job, errCh chan<- error) {
    for {
        select {
        case <-ctx.Done():
            errCh <- fmt.Errorf("worker cancelled: %w", ctx.Err())
            return
        case job, ok := <-jobs:
            if !ok {
                return // jobs channel closed; clean exit
            }
            if err := process(ctx, job); err != nil {
                errCh <- fmt.Errorf("process job %v: %w", job.ID, err)
                return
            }
        }
    }
}

func runPipeline(ctx context.Context, jobs []Job) error {
    ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
    defer cancel()

    jobCh := make(chan Job, len(jobs))
    errCh := make(chan error, 1)

    go worker(ctx, jobCh, errCh)

    for _, j := range jobs {
        jobCh <- j
    }
    close(jobCh)

    select {
    case err := <-errCh:
        return err
    case <-ctx.Done():
        return fmt.Errorf("pipeline timed out: %w", ctx.Err())
    }
}

ctx

%w

Constraints

MUST DO

• Use gofmt and golangci-lint on all code
• Add context.Context to all blocking operations
• Handle all errors explicitly (no naked returns)
• Write table-driven tests with subtests
• Document all exported functions, types, and packages
• Use

  X | Y

  union constraints for generics (Go 1.18+)
• Propagate errors with fmt.Errorf("%w", err)
• Run race detector on tests (-race flag)

MUST NOT DO

• Ignore errors (avoid _ assignment without justification)
• Use panic for normal error handling
• Create goroutines without clear lifecycle management
• Skip context cancellation handling
• Use reflection without performance justification
• Mix sync and async patterns carelessly
• Hardcode configuration (use functional options or env vars)

Output Templates

1. Interface definitions (contracts first)
2. Implementation files with proper package structure
3. Test file with table-driven tests
4. Brief explanation of concurrency patterns used

Knowledge Reference