Magic Number (ARCH5182)

Key go.quality.magic-number · Severity info · Category quality

Unexplained numeric literals inside expressions hide intent and are hard to change in every place. Extract them into a meaningful constant.

Incorrect

func Retry(fn func() error) error {
    for i := 0; i < 5; i++ {
        if err := fn(); err == nil {
            return nil
        }
        time.Sleep(250 * time.Millisecond)
    }
    return errExhausted
}

Correct

const (
    maxRetries = 5
    retryDelay = 250 * time.Millisecond
)

func Retry(fn func() error) error {
    for i := 0; i < maxRetries; i++ {
        if err := fn(); err == nil {
            return nil
        }
        time.Sleep(retryDelay)
    }
    return errExhausted
}

Fix

Define numeric literals as a const with a descriptive name.