Function patternWithRoot

src/utils/permissions/filesystem.ts:853–917

(
  pattern: string,
  source: PermissionRuleSource,
)

}

function patternWithRoot(
  pattern: string,
  source: PermissionRuleSource,
): {
  relativePattern: string
  root: string | null
} {
  if (pattern.startsWith(`${DIR_SEP}${DIR_SEP}`)) {
    // Patterns starting with // resolve relative to /
    const patternWithoutDoubleSlash = pattern.slice(1)

    // On Windows, check if this is a POSIX-style drive path like //c/Users/...
    // Note: UNC paths (//server/share) will not match this regex and will be treated
    // as root-relative patterns, which may need separate handling in the future
    if (
      getPlatform() === 'windows' &&
      patternWithoutDoubleSlash.match(/^\/[a-z]\//i)
    ) {
      // Convert POSIX path to Windows format
      // The pattern is like /c/Users/... so we convert it to C:\Users\...
      const driveLetter = patternWithoutDoubleSlash[1]?.toUpperCase() ?? 'C'
      // Keep the pattern in POSIX format since relativePath returns POSIX paths
      const pathAfterDrive = patternWithoutDoubleSlash.slice(2)

      // Extract the drive root (C:\) and the rest of the pattern
      const driveRoot = `${driveLetter}:\\`
      const relativeFromDrive = pathAfterDrive.startsWith('/')
        ? pathAfterDrive.slice(1)
        : pathAfterDrive

      return {
        relativePattern: relativeFromDrive,
        root: driveRoot,
      }
    }

    return {
      relativePattern: patternWithoutDoubleSlash,
      root: DIR_SEP,
    }
  } else if (pattern.startsWith(`~${DIR_SEP}`)) {
    // Patterns starting with ~/ resolve relative to homedir
    return {
      relativePattern: pattern.slice(1),
      root: homedir().normalize('NFC'),
    }
  } else if (pattern.startsWith(DIR_SEP)) {
    // Patterns starting with / resolve relative to the directory where settings are stored (without .claude/)
    return {
      relativePattern: pattern,
      root: rootPathForSource(source),
    }
  }
  // No root specified, put it with all the other patterns
  // Normalize patterns that start with "./" to remove the prefix
  // This ensures that patterns like "./.env" match files like ".env"
  let normalizedPattern = pattern
  if (pattern.startsWith(`.${DIR_SEP}`)) {