Function Create

pkg/worktree/worktree.go:133–182

Create creates a new git worktree for the repository containing dir and returns it. The worktree lives under the data directory and checks out a freshly created branch so the agent's changes stay isolated from the user's checkout. When name is empty, a friendly random name (e.g. "focused_turing") i

(ctx context.Context, dir, name string, opts ...CreateOption)

// Returns [ErrNotGitRepository] when dir is not inside a git worktree, and
// [ErrInvalidName] when an explicit name is not a safe path/branch component.
func Create(ctx context.Context, dir, name string, opts ...CreateOption) (*Worktree, error) {
	cfg := resolveCreateConfig(opts)

	root, err := repoRoot(ctx, dir)
	if err != nil {
		return nil, err
	}

	if name == "" {
		name = namesgenerator.GetRandomName(0)
	} else if err := validateName(name); err != nil {
		return nil, err
	}

	branch := "worktree-" + name
	dest := filepath.Join(cfg.root, "worktrees", name)

	if _, err := os.Stat(dest); err == nil {
		return nil, fmt.Errorf("%w: worktree %q already exists at %s", ErrInvalidName, name, dest)
	}

	// The branch start-point: a user-chosen base ref, or the current HEAD.
	// `git worktree add -b <branch> <dest> [<start-point>]` omits the
	// start-point when none was requested, preserving the default behaviour.
	addArgs := []string{"worktree", "add", "-b", branch, dest}
	if cfg.base != "" {
		if err := fetchBase(ctx, root, cfg.base); err != nil {
			return nil, err
		}
		addArgs = append(addArgs, cfg.base)
	}

	if err := git(ctx, root, addArgs...); err != nil {
		if cfg.base != "" {
			return nil, fmt.Errorf("%w: %s: %w", ErrInvalidBase, cfg.base, err)
		}
		return nil, fmt.Errorf("creating git worktree: %w", err)
	}

	wt := &Worktree{Dir: dest, Branch: branch, Name: name, SourceDir: root}

	// Record the branch point so [Status] can later tell whether the
	// session added commits. A brand-new repository with no commits has no
	// HEAD yet; leave BaseCommit empty in that case.
	if head, err := gitOutput(ctx, dest, "rev-parse", "HEAD"); err == nil {
		wt.BaseCommit = head
	}

	return wt, nil
}

// CreatePR creates a git worktree that checks out an existing GitHub pull
// request so the agent can continue it. ref is a PR number ("123") or a