apperrors

Documentation

Overview

Package apperrors provides custom error handling for the Tempo CLI.

Error Handling Strategy:

This package standardizes error handling throughout the Tempo codebase with the following guidelines:

1. Creating New Errors: Use apperrors.Wrap() to create new errors with context, optionally wrapping an underlying cause:

   return apperrors.Wrap("failed to read config file", err, filename)

   The first argument after the error is treated as the cause. Additional arguments are formatted into the message.

2. Error Wrapping: Always use apperrors.Wrap() instead of fmt.Errorf() for error wrapping. This ensures consistent error formatting and proper error chain support:

   // Good return apperrors.Wrap("failed to process file", err)

   // Avoid return fmt.Errorf("failed to process file: %w", err)

3. Sentinel Errors: Define package-level sentinel errors using fmt.Errorf() for comparison with errors.Is():

   var ErrNotFound = fmt.Errorf("resource not found")

4. Error Attributes: Use WithAttr() to add structured metadata to errors for debugging:

   err := apperrors.Wrap("validation failed", nil) err.(*TempoError).WithAttr("field", "email").WithAttr("value", userInput)

5. Error Chains: The package properly implements Unwrap() to support Go's error chain traversal with errors.Is() and errors.As().

6. Logging: Use LogErrorChain() for simple error logging or LogErrorChainWithAttrs() for detailed error information including attributes.

Index

• func LogErrorChain(err error)
• func LogErrorChainWithAttrs(err error)
• func Wrap(msg string, args ...any) error
• type TempoError
  • func NewTempoError(message string, cause error) *TempoError
  • func (e *TempoError) Error() string
  • func (e *TempoError) ToJSON() ([]byte, error)
  • func (e *TempoError) Unwrap() error
  • func (e *TempoError) WithAttr(key string, value any) *TempoError
• type TempoErrorInterface

Functions

func LogErrorChain

func LogErrorChain(err error)

LogErrorChain logs an error chain to the console.

func LogErrorChainWithAttrs

func LogErrorChainWithAttrs(err error)

LogErrorChainWithAttrs logs an error chain with additional attributes in a structured format.

func Wrap

func Wrap(msg string, args ...any) error

Wrap creates a TempoError with a given message, optional cause, and formatting arguments. If the first variadic argument is an error, it is treated as the cause.

Types

type TempoError

type TempoError struct {
	Message string         // Context message for the error
	Cause   error          // Underlying cause of the error, if any
	Attrs   map[string]any // Additional attributes for the error
}

TempoError represents an error with an additional context message, cause, and attributes.

func NewTempoError

func NewTempoError(message string, cause error) *TempoError

NewTempoError creates a new TempoError instance.

func (*TempoError) Error

func (e *TempoError) Error() string

Error returns the context message of the TempoError.

func (*TempoError) ToJSON

func (e *TempoError) ToJSON() ([]byte, error)

func (*TempoError) Unwrap

func (e *TempoError) Unwrap() error

Unwrap returns the underlying cause of the error, if any.

func (*TempoError) WithAttr

func (e *TempoError) WithAttr(key string, value any) *TempoError

WithAttr adds a key-value pair to the attributes and returns the updated error.

type TempoErrorInterface

type TempoErrorInterface interface {
	error
	Attrs() map[string]any
}

TempoErrorInterface defines the interface for TempoError with extended capabilities.