go-errors-with-datadog-way.go

package main

import (
	"errors"
	"fmt"

	customError "github.com/pkg/errors"
)

type stackTracer interface {
	StackTrace() customError.StackTrace
}

func main() {
	fmt.Println("Example using standard library:")
	errStd := readFileStandard()
	if errStd != nil {
		fmt.Printf("%v\n", errStd)  // This will only print the error message
		fmt.Printf("%+v\n", errStd) // This will print the error message, as there is no stack trace
	}

	fmt.Println("\nExample using pkg/errors:")
	err := readFilePkg()
	if err != nil {
		fmt.Printf("%v\n", err)  // This will only print the error message
		fmt.Printf("%+v\n", err) // This will print the error message and the stack trace
	}

	fmt.Println("Example using DataDog way to print stack trace:")
	var stack string
	if serr, ok := err.(stackTracer); ok {
		st := serr.StackTrace()
		stack = fmt.Sprintf("%+v", st)
		if len(stack) > 0 && stack[0] == '\n' {
			stack = stack[1:]
		}

		fmt.Printf("\nStack trace:\n%s\n", stack)
	}
}

// Standard library error handling
func readFileStandard() error {
	return fmt.Errorf("failed to read file: %w", readStandard())
}

func readStandard() error {
	return errors.New("an error occurred")
}

// pkg/errors error handling
func readFilePkg() error {
	return customError.Wrap(readPkg(), "failed to read file")
}

func readPkg() error {
	return customError.New("an error occurred")
}