The ActiveSupport test suite only passes currently if it uses the latest unreleased commits for dalli, and a patch for Builder:
https://github.com/tenderlove/builder/pull/6

Beyond that, all external dependencies (at least, to the extent they’re used by ActiveSupport) are happy, including Nokogiri as of 1.8.0.

By default, this method formats US number. This commit extends its
functionality to format number for other countries with a custom regular
expression.

    number_to_phone(18812345678, pattern: /(\d{3})(\d{4})(\d{4})/)
    # => 188-1234-5678

The output phone number is divided into three groups, so the regexp
should also match three groups of numbers.

These classes are not meant to be public.

This reads a lot better, and we won't need to try start_with? for blank
delimiters.

Also rename method name to read better.

The conversion without area code already changed the passed number in
place, so change the other method to do the same.

Due to the overall complexity of each method individually as well as the
global shared private module methods, this pulls each helper into it's
own converter class inheriting from a generic `NumberBuilder` class.

* The `NumberBuilder` class contains the private methods needed for each helper
method an eliminates the need for special definition of specialized private
module methods.
* The `ActiveSupport::NumberHelper::DEFAULTS` constant has been moved
into the `NumberBuilder` class because the `NumberBuilder` is the only
class which needs access to it.
* For each of the builders, the `#convert` method is broken down to
smaller parts and extracted into private methods for clarity of purpose.
* Most of the mutation that once was necessary has now been eliminated.
* Several of the mathematical operations for percentage, delimited, and
rounded have been moved into private methods to ease readability and
clarity.
* Internationalization is still a bit crufty, and definitely could be
improved, but it is functional and a bit easier to follow.

The following helpers were extracted into their respective classes.

* `#number_to_percentage` -> `NumberToPercentageConverter`
* `#number_to_delimited` -> `NumberToDelimitedConverter`
* `#number_to_phone` -> `NumberToPhoneConverter`
* `#number_to_currency` -> `NumberToCurrencyConverter`
* `#number_to_rounded` -> `NumberToRoundedConverter`
* `#number_to_human_size` -> `NumberToHumanSizeConverter`
* `#number_to_human` -> `NumberToHumanConverter`