module RSpec::Core::Metadata

def self.relative_path_regex

http://rubular.com/r/sbAMHFrOx1
http://rubular.com/r/duOrD4i3wb
http://rubular.com/r/fT0gmX6VJX

before and the character after the string if any.
separator, or at the end of the string. Match groups are the character
whitespace, containing the current path, either postfixed with the
Matches strings either at the beginning of the input or prefixed with a 
def self.relative_path_regex
  @relative_path_regex ||= /(\A|\s)#{File.expand_path('.')}(#{File::SEPARATOR}|\s|\Z)/
end