Add process that generate bash/fish/zsh completion file

cmd/root.go

@@ -1,7 +1,16 @@
 package cmd
 
 import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
 	"github.com/nao1215/gup/internal/assets"
+	"github.com/nao1215/gup/internal/completion"
+	"github.com/nao1215/gup/internal/file"
 	"github.com/nao1215/gup/internal/print"
 	"github.com/spf13/cobra"
 )
@@ -15,7 +24,173 @@ If you update all binaries, just run '$ gup update'`,
 // Execute run gup process.
 func Execute() {
 	assets.DeployIconIfNeeded()
+	deployShellCompletionFileIfNeeded(rootCmd)
+
+	rootCmd.CompletionOptions.DisableDefaultCmd = true
 	if err := rootCmd.Execute(); err != nil {
 		print.Err(err)
 	}
 }
+
+// deleteShellCompletionFileIfNeeded creates the shell completion file.
+// If the file with the same contents already exists, it is not created.
+func deployShellCompletionFileIfNeeded(cmd *cobra.Command) {
+	makeBashCompletionFileIfNeeded(cmd)
+	makeFishCompletionFileIfNeeded(cmd)
+	makeZshCompletionFileIfNeeded(cmd)
+}
+
+func makeBashCompletionFileIfNeeded(cmd *cobra.Command) {
+	if existSameBashCompletionFile(cmd) {
+		return
+	}
+
+	path := completion.BashCompletionFilePath()
+	if err := os.MkdirAll(filepath.Dir(path), 0775); err != nil {
+		print.Err(fmt.Errorf("can not create bash-completion file: %w", err))
+		return
+	}
+
+	if err := cmd.GenBashCompletionFile(path); err != nil {
+		print.Err(fmt.Errorf("can not create bash-completion file: %w", err))
+		return
+	}
+	print.Info("create bash-completion file: " + path)
+}
+
+func makeFishCompletionFileIfNeeded(cmd *cobra.Command) {
+	if isSameFishCompletionFile(cmd) {
+		return
+	}
+
+	path := completion.FishCompletionFilePath()
+	if err := os.MkdirAll(filepath.Dir(path), 0775); err != nil {
+		print.Err(fmt.Errorf("can not create fish-completion file: %w", err))
+		return
+	}
+
+	if err := cmd.GenFishCompletionFile(path, false); err != nil {
+		print.Err(fmt.Errorf("can not create fish-completion file: %w", err))
+		return
+	}
+	print.Info("create fish-completion file: " + path)
+}
+
+func makeZshCompletionFileIfNeeded(cmd *cobra.Command) {
+	if isSameZshCompletionFile(cmd) {
+		return
+	}
+
+	path := completion.ZshCompletionFilePath()
+	if err := os.MkdirAll(filepath.Dir(path), 0775); err != nil {
+		print.Err(fmt.Errorf("can not create zsh-completion file: %w", err))
+		return
+	}
+
+	if err := cmd.GenZshCompletionFile(path); err != nil {
+		print.Err(fmt.Errorf("can not create zsh-completion file: %w", err))
+		return
+	}
+	print.Info("create zsh-completion file: " + path)
+
+	const zshFpath = "fpath=(~/.zsh/completion $fpath)"
+	zshrcPath := completion.ZshrcPath()
+	if !file.IsFile(zshrcPath) {
+		fp, err := os.OpenFile(zshrcPath, os.O_RDWR|os.O_CREATE, 0664)
+		if err != nil {
+			print.Err(fmt.Errorf("can not add zsh $fpath in .zshrc: %w", err))
+			return
+		}
+		defer fp.Close()
+		if _, err := fp.WriteString(zshFpath); err != nil {
+			print.Err(fmt.Errorf("can not add zsh $fpath in .zshrc: %w", err))
+			return
+		}
+	}
+
+	zshrc, err := ioutil.ReadFile(zshrcPath)
+	if err != nil {
+		print.Err(fmt.Errorf("can not read .zshrc: %w", err))
+		return
+	}
+
+	if strings.Contains(string(zshrc), zshFpath) {
+		return
+	}
+
+	fp, err := os.OpenFile(zshrcPath, os.O_RDWR|os.O_APPEND, 0664)
+	if err != nil {
+		print.Err(fmt.Errorf("can not add zsh $fpath in .zshrc: %w", err))
+		return
+	}
+	defer fp.Close()
+
+	if _, err := fp.WriteString(zshFpath); err != nil {
+		print.Err(fmt.Errorf("can not add zsh $fpath in .zshrc: %w", err))
+		return
+	}
+}
+
+func existSameBashCompletionFile(cmd *cobra.Command) bool {
+	path := completion.BashCompletionFilePath()
+	if !file.IsFile(path) {
+		return false
+	}
+
+	currentBashCompletion := new(bytes.Buffer)
+	cmd.GenBashCompletion(currentBashCompletion)
+
+	bashCompletionInLocal, err := ioutil.ReadFile(path)
+	if err != nil {
+		return false
+	}
+
+	if bytes.Compare(currentBashCompletion.Bytes(), bashCompletionInLocal) != 0 {
+		return false
+	}
+	return true
+}
+
+func isSameFishCompletionFile(cmd *cobra.Command) bool {
+	path := completion.FishCompletionFilePath()
+	if !file.IsFile(path) {
+		return false
+	}
+
+	currentFishCompletion := new(bytes.Buffer)
+	if err := cmd.GenFishCompletion(currentFishCompletion, false); err != nil {
+		return false
+	}
+
+	fishCompletionInLocal, err := ioutil.ReadFile(path)
+	if err != nil {
+		return false
+	}
+
+	if bytes.Compare(currentFishCompletion.Bytes(), fishCompletionInLocal) != 0 {
+		return false
+	}
+	return true
+}
+
+func isSameZshCompletionFile(cmd *cobra.Command) bool {
+	path := completion.ZshCompletionFilePath()
+	if !file.IsFile(path) {
+		return false
+	}
+
+	currentZshCompletion := new(bytes.Buffer)
+	if err := cmd.GenFishCompletion(currentZshCompletion, false); err != nil {
+		return false
+	}
+
+	zshCompletionInLocal, err := ioutil.ReadFile(path)
+	if err != nil {
+		return false
+	}
+
+	if bytes.Compare(currentZshCompletion.Bytes(), zshCompletionInLocal) != 0 {
+		return false
+	}
+	return true
+}

internal/completion/completion.go

@@ -0,0 +1,28 @@
+package completion
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/nao1215/gup/internal/cmdinfo"
+)
+
+// BashCompletionFilePath return bash-completion file path.
+func BashCompletionFilePath() string {
+	return filepath.Join(os.Getenv("HOME"), ".config", "bash_completion.d", cmdinfo.Name())
+}
+
+// FishCompletionFilePath return fish-completion file path.
+func FishCompletionFilePath() string {
+	return filepath.Join(os.Getenv("HOME"), ".config", "fish", "completions", cmdinfo.Name()+".fish")
+}
+
+// ZshCompletionFilePath return zsh-completion file path.
+func ZshCompletionFilePath() string {
+	return filepath.Join(os.Getenv("HOME"), ".zsh", "completion", "_"+cmdinfo.Name())
+}
+
+// ZshrcPath return .zshrc path.
+func ZshrcPath() string {
+	return filepath.Join(os.Getenv("HOME"), ".zshrc")
+}