【golang】go errors 处理错误追踪打印堆栈信息

背景

使用原生go语言编程时，常常需要处理错误，然而golang中没有像java/python等其他语言的try-catch方式一样的方式来处理异常事件，只能通过函数返回值接收并处理错误。
在实践中，由于牛马的不熟练或随意处理错误（比如我），常常在各处打印错误日志，而实际翻找日志时很难定位错误根源。在中大型项目中，业务逻辑错综复杂，日志描述大量重复或者含糊不清，就很难排查问题了。

如果能根据在日志中看到错误的堆栈信息，是不是定位问题就变容易多了？！
https://github.com/pkg/errors 很符合我对错误处理的幻想，甚至比try-catch更方便。

使用

go get github.com/pkg/errors

package main

import (
	"fmt"

	"github.com/pkg/errors"
)

func a(x int) error {
	if x == 2 {
		//return errors.Errorf("error because x is %d", x) //  会记录调用栈
		return errors.New("[a] error because x is 2") // 会记录调用栈
	}
	return nil
}

func b(arr []int) error {
	for _, x := range arr {
		if err := a(x); err != nil {
			return errors.Wrap(err, "[b] failed to handle arr") // 包装，并且记录当前行的调用栈
			//return errors.WithMessage(err, "failed to handle arr") // 只包装，不记录当前行的调用栈
		}
	}
	return nil
}

func c() error {
	err := b([]int{1, 2, 3, 4, 5})
	if err != nil {
		return errors.WithMessage(err, "[c] error") // 只包装，不记录当前行的调用栈
	}
	return nil
}

func main() {
	err := c()
	if err != nil {
		fmt.Println("============================================")
		fmt.Printf("%v\n", err) // 打印错误信息
		fmt.Println("============================================")
		fmt.Printf("%v\n", errors.Cause(err)) // 打印错误根源信息
		fmt.Println("============================================")
		fmt.Printf("%+v\n", err) // 打印错误信息+堆栈信息
		fmt.Println("============================================")
	}
}

stdout:

============================================
[c] error: [b] failed to handle arr: [a] error because x is 2
============================================
[a] error because x is 2
============================================
[a] error because x is 2
main.a
	/Users/jinglong/Projects/my-go-projects/study/test_errors/main.go:12
main.b
	/Users/jinglong/Projects/my-go-projects/study/test_errors/main.go:19
main.c
	/Users/jinglong/Projects/my-go-projects/study/test_errors/main.go:28
main.main
	/Users/jinglong/Projects/my-go-projects/study/test_errors/main.go:36
runtime.main
	/Library/env/goenv/versions/1.21.13/src/runtime/proc.go:267
runtime.goexit
	/Library/env/goenv/versions/1.21.13/src/runtime/asm_arm64.s:1197
[b] failed to handle arr
main.b
	/Users/jinglong/Projects/my-go-projects/study/test_errors/main.go:20
main.c
	/Users/jinglong/Projects/my-go-projects/study/test_errors/main.go:28
main.main
	/Users/jinglong/Projects/my-go-projects/study/test_errors/main.go:36
runtime.main
	/Library/env/goenv/versions/1.21.13/src/runtime/proc.go:267
runtime.goexit
	/Library/env/goenv/versions/1.21.13/src/runtime/asm_arm64.s:1197
[c] error
============================================

参考

https://segmentfault.com/a/1190000045285259