Error Wrapping

Go wraps an error with context while preserving the original cause.

error_wrapping.go

package main

import (
	"errors"
	"fmt"
)

func main() {
	var operation = 
	base := errors.New("config missing")
	wrapped := fmt.Errorf("%s failed: %w", operation, base)

	fmt.Println("operation=", operation)
	fmt.Println("base=", base.Error())
	fmt.Println("has_error=", wrapped != nil)
	fmt.Println("message=", wrapped.Error())
}

package main

import (
	"errors"
	"fmt"
)

func main() {
	var operation = 
	base := errors.New("config missing")
	wrapped := fmt.Errorf("%s failed: %w", operation, base)

	fmt.Println("operation=", operation)
	fmt.Println("base=", base.Error())
	fmt.Println("has_error=", wrapped != nil)
	fmt.Println("message=", wrapped.Error())
}

package main

import (
	"errors"
	"fmt"
)

func main() {
	var operation = 
	base := errors.New("config missing")
	wrapped := fmt.Errorf("%s failed: %w", operation, base)

	fmt.Println("operation=", operation)
	fmt.Println("base=", base.Error())
	fmt.Println("has_error=", wrapped != nil)
	fmt.Println("message=", wrapped.Error())
}

wrapping `fmt.Errorf` with `%w` adds context without discarding the error underneath.