Function countWorktreeChanges

src/tools/ExitWorktreeTool/ExitWorktreeTool.ts:79–113

* Returns null when state cannot be reliably determined — callers that use * this as a safety gate must treat null as "unknown, assume unsafe" * (fail-closed). A silent 0/0 would let cleanupWorktree destroy real work. * * Null is returned when: * - git status or rev-list exit non-zero (lock fil

(
  worktreePath: string,
  originalHeadCommit: string | undefined,
)

 *   commits without a baseline, so we cannot prove the branch is clean.
 */
async function countWorktreeChanges(
  worktreePath: string,
  originalHeadCommit: string | undefined,
): Promise<ChangeSummary | null> {
  const status = await execFileNoThrow('git', [
    '-C',
    worktreePath,
    'status',
    '--porcelain',
  ])
  if (status.code !== 0) {
    return null
  }
  const changedFiles = count(status.stdout.split('\n'), l => l.trim() !== '')

  if (!originalHeadCommit) {
    // git status succeeded → this is a git repo, but without a baseline
    // commit we cannot count commits. Fail-closed rather than claim 0.
    return null
  }

  const revList = await execFileNoThrow('git', [
    '-C',
    worktreePath,
    'rev-list',
    '--count',
    `${originalHeadCommit}..HEAD`,
  ])
  if (revList.code !== 0) {
    return null
  }
  const commits = parseInt(revList.stdout.trim(), 10) || 0

  return { changedFiles, commits }
}

/**
 * Restore session state to reflect the original directory.