class RSpec::Core::RakeTask

def file_inclusion_specification
  if ENV['SPEC']
    FileList[ ENV['SPEC']].sort
  elsif String === pattern && !File.exist?(pattern)
    "--pattern #{escape pattern}"
  else
    # Before RSpec 3.1, we used `FileList` to get the list of matched
    # files, and then pass that along to the `rspec` command. Starting
    # with 3.1, we prefer to pass along the pattern as-is to the `rspec`
    # command, for 3 reasons:
    #
    #   * It's *much* less verbose to pass one `--pattern` option than a
    #     long list of files.
    #   * It ensures `task.pattern` and `--pattern` have the same
    #     behavior.
    #   * It fixes a bug, where
    #     `task.pattern = pattern_that_matches_no_files` would run *all*
    #     files because it would cause no pattern or file args to get
    #     passed to `rspec`, which causes all files to get run.
    #
    # However, `FileList` is *far* more flexible than the `--pattern`
    # option. Specifically, it supports individual files and directories,
    # as well as arrays of files, directories and globs, as well as other
    # `FileList` objects.
    #
    # For backwards compatibility, we have to fall back to using FileList
    # if the user has passed a `pattern` option that will not work with
    # `--pattern`.
    #
    # TODO: consider deprecating support for this and removing it in
    #   RSpec 4.
    FileList[pattern].sort.map { |file| escape file }
  end
end