Method: Path#relative_path_from

Defined in:
lib/path/implementation.rb

#relative_path_from(base_directory) ⇒ Object Also known as: relative_to, %

#relative_path_from returns a relative path from the given base_directory to the receiver. They must be both relative or both absolute.

It doesn’t access the filesystem and assumes no symlinks.

Raises:

  • (ArgumentError) —

    if it cannot find a relative path: Either the base is relative and contains ‘..’ (in that case you can expand both paths) or the paths are absolutes and on different drives (Windows).



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# File 'lib/path/implementation.rb', line 109

def relative_path_from(base_directory)
  dest = clean.path
  base = Path.new(base_directory).clean.path
  dest_prefix, dest_names = split_names(dest)
  base_prefix, base_names = split_names(base)

  unless SAME_PATHS[dest_prefix, base_prefix]
    raise ArgumentError, "different prefix: #{self.inspect} and #{base_directory.inspect}"
  end
  while d = dest_names.first and b = base_names.first and SAME_PATHS[d, b]
    dest_names.shift
    base_names.shift
  end
  raise ArgumentError, "base_directory has ..: #{base_directory.inspect}" if base_names.include? '..'
  # the number of names left in base is the ones we have to climb
  names = base_names.fill('..').concat(dest_names)
  return Path.new('.') if names.empty?
  Path.new(*names)
end