Escape token extraction

[erikreedstrom]

This change allows monkey-patched charsets that contain regex protected characters to be used.

For example, the following initializer declares a charset that adds -. As a result, any short token including the - will currently fail token extraction.

config/initializers/shortener.rb

module Shortener
  send(:remove_const, :CHARSETS) if const_defined?(:CHARSETS)

  CHARSETS = {
    # Exclude vowels to preclude errant creation of words
    alphanumsafe: (('b'..'z').to_a + ('b'..'Z').to_a).reject { |l| l =~ /[eiou]/i } + (0..9).to_a + %w(- _),
  }
end

Shortener.default_redirect = Rails.application.secrets.web_host_share
Shortener.unique_key_length = 6
Shortener.charset = :alphanumsafe

[erikreedstrom]

Test failure is issue with Rake 11.0 breaking change.
Ref: /lib/rake/task_manager.rb#L8

Need to pin Rake to < 11 or implement monkey patch.

[jpmcgrath]

@erikreedstrom Thanks.