欺骗以快速查找在Go中引发错误的文件和行号？

Question

In my journey with go discovered that there are no stacktraces. so whenever something breaks, all we get an simple string error message without any information where is this is coming from. This is in stark contrast with other languages where I am used to seing detailed stacktraces

For example, below is the error message from apex

$ cat event.json | apex invoke --logs webhook                                  
   ⨯ error parsing response: json: cannot unmarshal array into Go value of type map[string]interface {}

here its telling me that unmarshal to a map ins't working because event.json is an array. We have unmarshal to interface{} to support both arrays & maps.However, it doesn't tell me which file/line is causing this error.

Questions:

1. What is way to quickly find which file/line this error coming from?
2. In General, Are there tips/tricks which gophers use to get to the source of problem quickly from this string error message?
3. is this how stack traces are for most go projects or there are any best practices that should be followed?

Answer 1

What is way to quickly find which file/line this error coming from?

There are no default stacks printed unless it's an unrecovered panic.

In General, Are there tips/tricks which gophers use to get to the source of problem quickly from this string error message? is this how stack traces are for most go projects or there are any best practices that should be followed?

In General, you need to check error returns from most of the function calls. There are more than one way to do that. I usually use standard library package log to print out error logs with file and line numbers for easy debugging in simple programs. For example:

package main

import "log"
import "errors"

func init() { log.SetFlags(log.Lshortfile | log.LstdFlags) }

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

func main() {
    if err := callFunc(); err != nil {
        log.Println(err)
    }
}

http://play.golang.org/p/0iytNw7eZ7

output:

2009/11/10 23:00:00 main.go:14: error

Also, there are functions for you to print or retrieve current stacks in standard library runtime/debug, e.g. https://golang.org/pkg/runtime/debug/#PrintStack

There are many community efforts on bringing error handling easier, you can search error in GoDoc: https://godoc.org/?q=error

Hope these helps.