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Write CursorRules for Go projects by explicitly defining goroutine lifecycle management, channel usage patterns, and error propagation strategies. These rules ensure AI generates code following Go’s idiomatic concurrency model rather than generic async patterns—specifying exact requirements for sync.WaitGroup usage, error channels, worker pool patterns, and proper cleanup to prevent subtle concurrency bugs.

Why CursorRules Matter for Go Projects

Golang’s concurrency model and error handling differ significantly from other languages. The language’s approach to concurrency through goroutines and channels, combined with explicit error returns instead of exceptions, requires AI assistants to understand these idiomatic patterns. Without proper guidance, AI tools often generate code that either fails to compile or violates Go conventions.

When you configure CursorRules specifically for your Golang project, you ensure that every code suggestion follows your team’s established patterns for goroutine lifecycle management, channel usage, and error propagation. This consistency reduces review cycles and prevents subtle bugs that emerge from inconsistent concurrency implementations.

Configuring Concurrency Patterns in CursorRules

Your CursorRules should explicitly define how the AI should handle goroutine creation, management, and cleanup. Rather than allowing generic async patterns, specify exact requirements for your concurrency model.

For projects using the standard library’s concurrency primitives, your CursorRules should include guidance like this:

// Use goroutines with explicit error channels for result propagation
func workerPool(jobs <-chan Job, results chan<- Result, workers int) {
    var wg sync.WaitGroup
    for i := 0; i < workers; i++ {
        wg.Add(1)
        go func() {
            defer wg.Done()
            for job := range jobs {
                result, err := processJob(job)
                if err != nil {
                    results <- Result{Error: err}
                    continue
                }
                results <- Result{Value: result}
            }
        }()
    }
    wg.Wait()
    close(results)
}

This pattern demonstrates proper goroutine lifecycle management: explicit wait groups, channel-based communication, and graceful shutdown through channel closure. Your CursorRules should require the AI to follow similar patterns rather than spawning unbounded goroutines without cleanup mechanisms.

When your project uses worker pools or task queues, specify the exact pattern your team employs. Whether you use a simple channel-based approach or a library like errgroup for parallel operation coordination, the AI needs explicit instructions to match your implementation.

Enforcing Error Handling Conventions

Go’s error handling philosophy requires explicit error checking after every operation that can fail. AI assistants sometimes take shortcuts or generate verbose error handling that doesn’t match your project’s style. CursorRules should address both the presence and format of error handling.

Define clear rules for error wrapping:

// Use fmt.Errorf with %w for error wrapping to preserve error chains
func fetchUserData(ctx context.Context, id string) (*UserData, error) {
    resp, err := client.Get(ctx, "/users/"+id)
    if err != nil {
        return nil, fmt.Errorf("fetching user %s: %w", id, err)
    }

    var user UserData
    if err := json.Unmarshal(resp.Body, &user); err != nil {
        return nil, fmt.Errorf("unmarshaling user response: %w", err)
    }

    return &user, nil
}

Your CursorRules should specify whether errors should include context (like user IDs or operation names), how errors should be wrapped (fmt.Errorf with %w versus custom error types), and when to use sentinel errors versus custom error types.

For projects that benefit from custom error types, provide examples:

// Define custom error types for actionable error handling
type ValidationError struct {
    Field   string
    Message string
}

func (e *ValidationError) Error() string {
    return fmt.Sprintf("%s: %s", e.Field, e.Message)
}

func validateInput(input *Request) error {
    if input.Name == "" {
        return &ValidationError{Field: "name", Message: "cannot be empty"}
    }
    return nil
}

Structuring Context Propagation

Golang’s context package provides the standard mechanism for request-scoped values and cancellation. Your CursorRules should ensure the AI consistently propagates context through your call stacks.

Specify requirements like always accepting context as the first parameter, using context for timeout and cancellation, and avoiding context.Background() in production code except at the entry point:

func (s *Service) ProcessWithTimeout(ctx context.Context, req *Request) (*Response, error) {
    ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
    defer cancel()

    return s.process(ctx, req)
}

Channel Patterns and Buffering

Channel behavior varies based on your use case. Unbuffered channels provide synchronization guarantees while buffered channels improve throughput for batch processing. Your CursorRules should specify when to use each type.

For most RPC-style interactions, unbuffered channels ensure immediate error propagation:

// Unbuffered channel for synchronous error reporting
errCh := make(chan error)
go func() {
    errCh <- performOperation()
}()
if err := <-errCh; err != nil {
    return fmt.Errorf("operation failed: %w", err)
}

For producer-consumer patterns where producers shouldn’t block, specify buffered channels with appropriate capacity:

// Buffered channel with capacity matching batch size
jobs := make(chan Job, 100)

Integrating with Existing Code

Review your project’s existing implementations to identify patterns the AI should emulate. Extract common patterns from your codebase and incorporate them into CursorRules. Include actual code examples from your project rather than abstract descriptions.

For instance, if your project uses a specific retry pattern:

func retryWithBackoff(ctx context.Context, op func() error) error {
    backoff := time.Second
    maxBackoff := 30 * time.Second

    for attempts := 0; ; attempts++ {
        if err := op(); err != nil {
            if attempts >= 3 {
                return err
            }
            select {
            case <-ctx.Done():
                return ctx.Err()
            case <-time.After(backoff):
                backoff *= 2
                if backoff > maxBackoff {
                    backoff = maxBackoff
                }
            }
        } else {
            return nil
        }
    }
}

Include this exact implementation in your CursorRules so the AI generates consistent retry logic.

Testing Considerations

Your CursorRules should also address testing patterns. Go’s testing package requires specific conventions. Specify how tests should handle table-driven testing, when to use subtests, and how to structure test helper functions:

func TestProcess(t *testing.T) {
    tests := []struct {
        name    string
        input   string
        want    string
        wantErr bool
    }{
        {"valid input", "hello", "hello", false},
        {"empty input", "", "", true},
    }

    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            got, err := Process(tt.input)
            if (err != nil) != tt.wantErr {
                t.Errorf("Process() error = %v, wantErr %v", err, tt.wantErr)
                return
            }
            if got != tt.want {
                t.Errorf("Process() = %v, want %v", got, tt.want)
            }
        })
    }
}

Final Configuration Tips

Keep your CursorRules focused and specific rather than. Include only patterns that differ from standard Go idioms or that your project implements differently. Review and update CursorRules as your project evolves, ensuring new team members receive consistent guidance from the AI assistant.

The goal is generating code that passes your CI/CD pipeline without modification, with proper goroutine cleanup, idiomatic error handling, and consistent patterns throughout your codebase.

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