Go Error Handling Pattern

By Jon Wear ·

Source: https://go.dev/blog/error-handling-and-go

A common pattern for handling errors in Go with context wrapping:

func doSomething() error {
    result, err := someOperation()
    if err != nil {
        return fmt.Errorf("failed to do something: %w", err)
    }
    return nil
}

Using %w allows error unwrapping with errors.Is() and errors.As().

Multiple Error Checks

func processFile(path string) error {
    f, err := os.Open(path)
    if err != nil {
        return fmt.Errorf("open file: %w", err)
    }
    defer f.Close()

    data, err := io.ReadAll(f)
    if err != nil {
        return fmt.Errorf("read file: %w", err)
    }

    // use data...
    return nil
}

Mentions