completion.go

/*
Copyright The Helm Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package main

import (
	"bytes"
	"io"

	"github.com/pkg/errors"
	"github.com/spf13/cobra"
)

const completionDesc = `
Generate autocompletions script for Helm for the specified shell (bash or zsh).

This command can generate shell autocompletions. e.g.

	$ helm completion bash

Can be sourced as such

	$ source <(helm completion bash)
`

var (
	completionShells = map[string]func(out io.Writer, cmd *cobra.Command) error{
		"bash": runCompletionBash,
		"zsh":  runCompletionZsh,
	}
)

func newCompletionCmd(out io.Writer) *cobra.Command {
	shells := []string{}
	for s := range completionShells {
		shells = append(shells, s)
	}

	cmd := &cobra.Command{
		Use:   "completion SHELL",
		Short: "Generate autocompletions script for the specified shell (bash or zsh)",
		Long:  completionDesc,
		RunE: func(cmd *cobra.Command, args []string) error {
			return runCompletion(out, cmd, args)
		},
		ValidArgs: shells,
	}

	return cmd
}

func runCompletion(out io.Writer, cmd *cobra.Command, args []string) error {
	if len(args) == 0 {
		return errors.New("shell not specified")
	}
	if len(args) > 1 {
		return errors.New("too many arguments, expected only the shell type")
	}