Go Error Handling

Route by Need

• Wrapping errors with context → see wrapping/
• Defining sentinel errors → see sentinel/
• Checking error types → see checking/

Quick Check

• Never ignore errors (_ = fn())
• Wrap with context at boundaries
• Use errors.Is/As, not ==

Common Pattern

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

    if err := parse(f); err != nil {
        return fmt.Errorf("parse %s: %w", path, err)
    }
    return nil
}

Resources

• wrapping/ - Add context with fmt.Errorf %w
• sentinel/ - Define package-level errors
• checking/ - Type-safe error inspection