Function createWorktreeForSession

source code/utils/worktree.ts:704–780

(
  sessionId: string,
  slug: string,
  tmuxSessionName?: string,
  options?: { prNumber?: number },
)

}

export async function createWorktreeForSession(
  sessionId: string,
  slug: string,
  tmuxSessionName?: string,
  options?: { prNumber?: number },
): Promise<WorktreeSession> {
  // Must run before the hook branch below — hooks receive the raw slug as an
  // argument, and the git branch builds a path from it via path.join.
  validateWorktreeSlug(slug)

  const originalCwd = getCwd()

  // Try hook-based worktree creation first (allows user-configured VCS)
  if (hasWorktreeCreateHook()) {
    const hookResult = await executeWorktreeCreateHook(slug)
    logForDebugging(
      `Created hook-based worktree at: ${hookResult.worktreePath}`,
    )

    currentWorktreeSession = {
      originalCwd,
      worktreePath: hookResult.worktreePath,
      worktreeName: slug,
      sessionId,
      tmuxSessionName,
      hookBased: true,
    }
  } else {
    // Fall back to git worktree
    const gitRoot = findGitRoot(getCwd())
    if (!gitRoot) {
      throw new Error(
        'Cannot create a worktree: not in a git repository and no WorktreeCreate hooks are configured. ' +
          'Configure WorktreeCreate/WorktreeRemove hooks in settings.json to use worktree isolation with other VCS systems.',
      )
    }

    const originalBranch = await getBranch()

    const createStart = Date.now()
    const { worktreePath, worktreeBranch, headCommit, existed } =
      await getOrCreateWorktree(gitRoot, slug, options)

    let creationDurationMs: number | undefined
    if (existed) {
      logForDebugging(`Resuming existing worktree at: ${worktreePath}`)
    } else {
      logForDebugging(
        `Created worktree at: ${worktreePath} on branch: ${worktreeBranch}`,
      )
      await performPostCreationSetup(gitRoot, worktreePath)
      creationDurationMs = Date.now() - createStart
    }

    currentWorktreeSession = {
      originalCwd,
      worktreePath,
      worktreeName: slug,