Golang error handling

Tags: go golang error

Different ways in which we can handle errors in Golang.

Using Go default error handling

Golang error handling is different from the traditional programming language.

// https://goplay.tools/snippet/1FBSURLzkxb
package main

import (
	"errors"
	"fmt"
	"log"
)

func A() error {
	return errors.New("A error")
}

func B() error {
	return fmt.Errorf("Call A(), %+v", A())
}
func main() {
	fmt.Println("Hello World")
	err := B()
	if err != nil {
		log.Printf("Call B(), %+v", err)
	}
}

In func A() we are creating a new Error with errors.New. This is a custom error. In func B() we are again receiving an error. Now either we can log this or send error back to the caller. We did create a new error using fmt.Errorf. In func main() we are logging the error. Output will look like this,

Hello World
2022/11/26 17:55:05 Call B(), Call A(), A error

Using github.com/pkg/errors

This particular package is now archived. But still available for download via go get command.

// https://goplay.tools/snippet/CThylnUxj4i
package main

import (
	"fmt"
	"log"
	"github.com/pkg/errors"
)

func A() error {
	return errors.New("A error")
}

func B() error {
	return errors.Wrap(A(), "Call A()")
}
func main() {
	fmt.Println("Hello World")
	err := B()
	if err != nil {
		log.Printf("Call B(), %+v", err)
	}
}

We are creating a new error with this package github.com/pkg/errors. errors.Wrap() will add the previous error with the stack trace. While printing the error, %+v will add the stack trace.

Hello World
[T+0000ms]
2009/11/10 23:00:00 Call B(), A error
main.A
	/tmp/sandbox2422463901/prog.go:12
main.B
	/tmp/sandbox2422463901/prog.go:16
main.main
	/tmp/sandbox2422463901/prog.go:21
runtime.main
	/usr/local/go-faketime/src/runtime/proc.go:250
runtime.goexit
	/usr/local/go-faketime/src/runtime/asm_amd64.s:1594
Call A()
main.B
	/tmp/sandbox2422463901/prog.go:16
main.main
	/tmp/sandbox2422463901/prog.go:21
runtime.main
	/usr/local/go-faketime/src/runtime/proc.go:250
runtime.goexit
	/usr/local/go-faketime/src/runtime/asm_amd64.s:1594
[T+0001ms]
Related Posts