Error Handling Exercises

Master Go’s error handling patterns with exercises on custom errors and retry logic.

Exercises in This Section

Exercise	Difficulty	Time	Description
Custom Errors	Easy	15 min	Create custom error types with context
Retry Patterns	Medium	25 min	Implement exponential backoff retry logic

Key Concepts Covered

• Error interface: Implementing the error interface
• Custom errors: Adding context and metadata to errors
• Error wrapping: Using fmt.Errorf with %w
• errors.Is/As: Checking error types and values
• Retry patterns: Exponential backoff, jitter

Prerequisites

Before starting these exercises, you should be comfortable with:

• Go interfaces
• The error interface
• Chapter 2: Error Handling Patterns

Tips

1. Errors should provide enough context to understand what went wrong
2. Wrap errors at layer boundaries to add context
3. Use sentinel errors sparingly - prefer error types