completion.go

package cmd

import (
	"fmt"
	"os"
	"strings"

	"github.com/spf13/cobra"
)

var (
	completionLong = `
	Output shell completion code for the specified shell (bash or zsh).
	The shell code must be evaluated to provide interactive
	completion of gloo-connect commands.  This can be done by sourcing it from
	the .bash_profile.

	Note for zsh users: [1] zsh completions are only supported in versions of zsh >= 5.2`

	completionExample = `
	# Installing bash completion on macOS using homebrew
	## If running Bash 3.2 included with macOS
	  	brew install bash-completion
	## or, if running Bash 4.1+
	    brew install bash-completion@2
	## You may need add the completion to your completion directory
	    gloo-connect completion bash > $(brew --prefix)/etc/bash_completion.d/gloo-connect
	# Installing bash completion on Linux
	## Load the gloo-connect completion code for bash into the current shell
	    source <(gloo-connect completion bash)
	## Write bash completion code to a file and source if from .bash_profile
	    gloo-connect completion bash > ~/.gloo-connect/completion.bash.inc
	    printf "
 	     # gloo-connect shell completion
	      source '$HOME/.gloo-connect/completion.bash.inc'
	      " >> $HOME/.bash_profile
	    source $HOME/.bash_profile
	# Load the gloo-connect completion code for zsh[1] into the current shell
	    source <(gloo-connect completion zsh)
	# Set the gloo-connect completion code for zsh[1] to autoload on startup
	    gloo-connect completion zsh > "${fpath[1]}/_gloo-connect"`
)

func completionCmd() *cobra.Command {
	cmd := &cobra.Command{
		Use:       "completion SHELL",
		Short:     "generate auto completion for your shell",
		Long:      completionLong,
		Example:   completionExample,
		Args:      cobra.ExactArgs(1),
		ValidArgs: []string{"bash", "zsh"},
		Run: func(c *cobra.Command, a []string) {
			switch strings.ToLower(a[0]) {
			case "bash":
				if err := c.Parent().GenBashCompletion(os.Stdout); err != nil {
					fmt.Println("Unable to generate bash completion", err)
					os.Exit(1)
				}
			case "zsh":
				if err := c.Parent().GenZshCompletion(os.Stdout); err != nil {
					fmt.Println("Unable to generate zsh completion", err)
					os.Exit(1)
				}
			default:
				fmt.Println("Unsupported shell", a[0])
			}
		},
	}
	return cmd
}