Debug file other than main.go in VS Code

Question

I am writing a CLI in go using VS code editor. I am not able to figure out how to debug a code section.

My directory structure is :

- test
  - main.go
  - cmd
    - login.go
    - root.go

1. I have set breakpoints in login.go but if I run "Start Debugging" in this file, I get error

Can not debug non-main package
Process exiting with code: 1

2. I tried running debugger in main.go but the debugger won't go to login.go file as I we have not explicitly written test login

API server listening at: 127.0.0.1:48423
A longer description that spans multiple lines and likely contains
examples and usage of using your application. For example:
cd .
Cobra is a CLI library for Go that empowers applications.
This application is a tool to generate the needed files
to quickly create a Cobra application.

Usage:
  test [command]

Available Commands:
  help        Help about any command
  login       A brief description of your command

Flags:
      --config string   config file (default is $HOME/.test.yaml)
  -h, --help            help for test
  -t, --toggle          Help message for toggle

Use "test [command] --help" for more information about a command.

1. main.go file

package main

import "test/cmd"

func main() {
  cmd.Execute()
}

2. login.go file

package cmd

import (
    "fmt"
    "github.com/spf13/cobra"
)

// loginCmd represents the login command
var loginCmd = &cobra.Command{
    Run: func(cmd *cobra.Command, args []string) {
        fmt.Println("login called")
        name, _ := cmd.Flags().GetString("username")
        pwd, _ := cmd.Flags().GetString("password")
        userInfo := name + ":" + pwd
    },
}

func init() {
    rootCmd.AddCommand(loginCmd)

    // Here you will define your flags and configuration settings.
    loginCmd.Flags().StringP("username", "u", "", "Specifies the user")
    loginCmd.Flags().StringP("password", "p", "", "Specifies the password for the user")
    loginCmd.Flags().StringP("manager", "m", "", "Specifies the environement where user wants to login")
}

3. settings.json

{
    "go.gopath":"/Users/deepakpatankar/go"
}

4. launch.json

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Launch",
            "type": "go",
            "request": "launch",
            "mode": "auto",
            "program": "${fileDirname}",
            "env": {},
            "args": []
        }
    ]
}

Please guide me how I can see the variable values in debug mode like for variable name. Though using Println is fine, but this source code is part of a bigger project, so I want to see how I can use the debugger ?

Answer 1

You can add flags to the "args": [] array in your vscode settings like this:

"args": ["login", "-u", "username", "-p", "password"]

This will make sure when you run debug you end up in the login command with the given flags.