[Fix] Derive worktree name from -b when no name given

cmd/worktree.go

@@ -15,6 +15,7 @@ import (
 
 var (
 	wtBaseBranch   string
+	wtDupBase      string
 	wtForce        bool
 	wtDeleteBranch bool
 	wtDryRun       bool
@@ -40,20 +41,31 @@ bare repository (.bare) + worktree pattern.
 }
 
 var wtAddCmd = &cobra.Command{
-	Use:   "add <name> [name...]",
+	Use:   "add [name...]",
 	Short: "Create new worktrees with new branches",
 	Long: `Create one or more worktrees with new branches.
 
 The branch name will be the same as the worktree directory name.
+When no name is given but -b is set, the worktree name is derived from
+the base branch (useful for checking out an existing branch).
 
 Examples:
   gmc wt add feature-login                    # Create one worktree
   gmc wt add feat-a feat-b feat-c             # Create multiple worktrees
   gmc wt add feature-login -b main            # Create based on main branch
   gmc wt add feature-login --sync             # Sync base branch before add
-  gmc wt add hotfix-bug123 -b release`,
-	Args: cobra.MinimumNArgs(1),
+  gmc wt add hotfix-bug123 -b release
+  gmc wt add -b feat/existing-branch          # Name derived from -b`,
+	Args: func(_ *cobra.Command, args []string) error {
+		if len(args) == 0 && strings.TrimSpace(wtBaseBranch) == "" {
+			return errors.New("requires at least 1 arg or -b/--base flag")
+		}
+		return nil
+	},
 	RunE: func(_ *cobra.Command, args []string) error {
+		if len(args) == 0 {
+			args = []string{wtBaseBranch}
+		}
 		wtClient := newWorktreeClient()
 		return runWorktreeAdd(wtClient, args)
 	},
@@ -210,13 +222,14 @@ func init() {
 	wtCloneCmd.Flags().StringVar(&wtProjectName, "name", "", "Custom project directory name")
 
 	// Flags for dup command
-	wtDupCmd.Flags().StringVarP(&wtBaseBranch, "base", "b", "main", "Base branch to create from")
+	wtDupCmd.Flags().StringVarP(&wtDupBase, "base", "b", "main", "Base branch to create from")
 
 	// Flags for prune command
 	wtPruneCmd.Flags().StringVarP(&wtPruneBase, "base", "b", "", "Base branch to check merge status against")
 	wtPruneCmd.Flags().BoolVarP(&wtPruneForce, "force", "f", false, "Force removal even if worktree is dirty")
 	wtPruneCmd.Flags().BoolVar(&wtPruneDryRun, "dry-run", false, "Preview what would be removed without making changes")
-	wtPruneCmd.Flags().BoolVar(&wtPrunePRAware, "pr-aware", false, "Check GitHub PR state before pruning (requires gh CLI)")
+	wtPruneCmd.Flags().BoolVar(&wtPrunePRAware, "pr-aware", false,
+		"Check GitHub PR state before pruning (requires gh CLI)")
 
 	// Flags for pr-review command
 	wtPrReviewCmd.Flags().StringVarP(&prRemote, "remote", "r", "",
@@ -541,7 +554,7 @@ func printWorktreeJSON(wtClient *worktree.Client, worktrees []worktree.Info) err
 
 func runWorktreeDup(wtClient *worktree.Client, args []string) error {
 	opts := worktree.DupOptions{
-		BaseBranch: wtBaseBranch,
+		BaseBranch: wtDupBase,
 		Count:      2,
 	}
 

cmd/worktree_test.go

@@ -49,7 +49,8 @@ func TestRunWorktreeDefault_ShowsWorktreesInNonBareRepo(t *testing.T) {
 
 func TestWtHookRemoveCmd_RejectsTrailingCharactersInIndex(t *testing.T) {
 	repoDir := initCmdTestRepo(t)
-	require.NoError(t, os.WriteFile(filepath.Join(repoDir, ".git", "gmc-share.yml"), []byte("hooks:\n  - cmd: echo ok\n"), 0o644))
+	cfgPath := filepath.Join(repoDir, ".git", "gmc-share.yml")
+	require.NoError(t, os.WriteFile(cfgPath, []byte("hooks:\n  - cmd: echo ok\n"), 0o644))
 
 	oldCwd, err := os.Getwd()
 	require.NoError(t, err)
@@ -99,9 +100,7 @@ func runGitCmd(t *testing.T, dir string, args ...string) string {
 	return string(output)
 }
 
-var execCommand = func(name string, args ...string) *exec.Cmd {
-	return exec.Command(name, args...)
-}
+var execCommand = exec.Command
 
 func TestRemoveAll_SkipsProtected(t *testing.T) {
 	repoDir := initCmdTestRepo(t)

internal/worktree/prune.go

@@ -49,7 +49,7 @@ var ghRunFunc = ghRunDefault
 
 func ghRunDefault(repoDir string, args ...string) ([]byte, error) {
 	if _, err := exec.LookPath("gh"); err != nil {
-		return nil, fmt.Errorf("gh CLI not found: install from https://cli.github.com")
+		return nil, errors.New("gh CLI not found: install from https://cli.github.com")
 	}
 	cmd := exec.Command("gh", args...)
 	cmd.Dir = repoDir
@@ -167,7 +167,9 @@ func ghPRStates(repoDir string) (map[string]ghPRInfo, error) {
 	return m, nil
 }
 
-func (c *Client) prunePRAware(opts PruneOptions, candidates []pruneCandidate, repoDir string, result PruneResult) (PruneResult, error) {
+func (c *Client) prunePRAware(
+	opts PruneOptions, candidates []pruneCandidate, repoDir string, result PruneResult,
+) (PruneResult, error) {
 	prMap, err := ghPRStates(repoDir)
 	if err != nil {
 		return result, err
@@ -227,7 +229,9 @@ func (c *Client) prunePRAware(opts PruneOptions, candidates []pruneCandidate, re
 	return result, nil
 }
 
-func (c *Client) pruneClassic(opts PruneOptions, candidates []pruneCandidate, root, baseBranch, repoDir string, result PruneResult) (PruneResult, error) {
+func (c *Client) pruneClassic(
+	opts PruneOptions, candidates []pruneCandidate, root, baseBranch, repoDir string, result PruneResult,
+) (PruneResult, error) {
 	var prunedAny bool
 
 	for _, cand := range candidates {

internal/worktree/resource.go

@@ -473,7 +473,9 @@ func (c *Client) NormalizeSharedResourcePath(path string) (string, error) {
 	return trimmed, nil
 }
 
-func (c *Client) resolveSharedPaths(repoRoot, targetRoot string, res SharedResource) (srcPath string, targetPath string, skip bool, err error) {
+func (c *Client) resolveSharedPaths(
+	repoRoot, targetRoot string, res SharedResource,
+) (srcPath string, targetPath string, skip bool, err error) {
 	targetPath, err = sanitizeTargetRelativePath(res.Path)
 	if err != nil {
 		return "", "", false, err