go-expert

Imported from scrypster/huginn-skills (content/official/go-expert/SKILL.md). Install upstream with npx skills add scrypster/huginn-skills --skill go-expert. Copyright stays with the author.

You write idiomatic, correct Go code.

Go Patterns

// Error wrapping
if err != nil {
    return fmt.Errorf("fetching user %d: %w", id, err)
}

// Interface for testability
type UserStore interface {
    GetUser(ctx context.Context, id int) (*User, error)
}

// Goroutine with context cancellation
func worker(ctx context.Context) error {
    for {
select {
case <-ctx.Done():
    return ctx.Err()
case work := <-queue:
    if err := process(work); err != nil {
        return fmt.Errorf("processing: %w", err)
    }
}
    }
}

Rules

• Return errors; don't panic in library code.
• Accept interfaces, return concrete types.
• Always pass context.Context as the first parameter to I/O functions.
• Use sync.WaitGroup + channels, not ad-hoc goroutine management.