Extract ActiveSupport::NumberHelper methods to classes

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`

1 files changed, 15 insertions, 308 deletions

diff --git a/activesupport/lib/active_support/number_helper.rb b/activesupport/lib/active_support/number_helper.rb
index 414960d2b1..6468bf55f0 100644
--- a/activesupport/lib/active_support/number_helper.rb
+++ b/activesupport/lib/active_support/number_helper.rb
@@ -1,115 +1,16 @@
-require 'active_support/core_ext/big_decimal/conversions'
-require 'active_support/core_ext/object/blank'
-require 'active_support/core_ext/hash/keys'
-require 'active_support/i18n'
 
 module ActiveSupport
   module NumberHelper
-    extend self
-
-    DEFAULTS = {
-      # Used in number_to_delimited
-      # These are also the defaults for 'currency', 'percentage', 'precision', and 'human'
-      format: {
-        # Sets the separator between the units, for more precision (e.g. 1.0 / 2.0 == 0.5)
-        separator: ".",
-        # Delimits thousands (e.g. 1,000,000 is a million) (always in groups of three)
-        delimiter: ",",
-        # Number of decimals, behind the separator (the number 1 with a precision of 2 gives: 1.00)
-        precision: 3,
-        # If set to true, precision will mean the number of significant digits instead
-        # of the number of decimal digits (1234 with precision 2 becomes 1200, 1.23543 becomes 1.2)
-        significant: false,
-        # If set, the zeros after the decimal separator will always be stripped (eg.: 1.200 will be 1.2)
-        strip_insignificant_zeros: false
-      },
-
-      # Used in number_to_currency
-      currency: {
-        format: {
-          format: "%u%n",
-          negative_format: "-%u%n",
-          unit: "$",
-          # These five are to override number.format and are optional
-          separator: ".",
-          delimiter: ",",
-          precision: 2,
-          significant: false,
-          strip_insignificant_zeros: false
-        }
-      },
-
-      # Used in number_to_percentage
-      percentage: {
-        format: {
-          delimiter: "",
-          format: "%n%"
-        }
-      },
 
-      # Used in number_to_rounded
-      precision: {
-        format: {
-          delimiter: ""
-        }
-      },
+    autoload :NumberToRoundedConverter,    "active_support/number_helper/number_to_rounded"
+    autoload :NumberToDelimitedConverter,  "active_support/number_helper/number_to_delimited"
+    autoload :NumberToHumanConverter,      "active_support/number_helper/number_to_human"
+    autoload :NumberToHumanSizeConverter,  "active_support/number_helper/number_to_human_size"
+    autoload :NumberToPhoneConverter,      "active_support/number_helper/number_to_phone"
+    autoload :NumberToCurrencyConverter,   "active_support/number_helper/number_to_currency"
+    autoload :NumberToPercentageConverter, "active_support/number_helper/number_to_percentage"
 
-      # Used in number_to_human_size and number_to_human
-      human: {
-        format: {
-          # These five are to override number.format and are optional
-          delimiter: "",
-          precision: 3,
-          significant: true,
-          strip_insignificant_zeros: true
-        },
-        # Used in number_to_human_size
-        storage_units: {
-          # Storage units output formatting.
-          # %u is the storage unit, %n is the number (default: 2 MB)
-          format: "%n %u",
-          units: {
-            byte: "Bytes",
-            kb: "KB",
-            mb: "MB",
-            gb: "GB",
-            tb: "TB"
-          }
-        },
-        # Used in number_to_human
-        decimal_units: {
-          format: "%n %u",
-          # Decimal units output formatting
-          # By default we will only quantify some of the exponents
-          # but the commented ones might be defined or overridden
-          # by the user.
-          units: {
-            # femto: Quadrillionth
-            # pico: Trillionth
-            # nano: Billionth
-            # micro: Millionth
-            # mili: Thousandth
-            # centi: Hundredth
-            # deci: Tenth
-            unit: "",
-            # ten:
-            #   one: Ten
-            #   other: Tens
-            # hundred: Hundred
-            thousand: "Thousand",
-            million: "Million",
-            billion: "Billion",
-            trillion: "Trillion",
-            quadrillion: "Quadrillion"
-          }
-        }
-      }
-    }
-
-    DECIMAL_UNITS = { 0 => :unit, 1 => :ten, 2 => :hundred, 3 => :thousand, 6 => :million, 9 => :billion, 12 => :trillion, 15 => :quadrillion,
-      -1 => :deci, -2 => :centi, -3 => :mili, -6 => :micro, -9 => :nano, -12 => :pico, -15 => :femto }
-
-    STORAGE_UNITS = [:byte, :kb, :mb, :gb, :tb]
+    extend self
 
     # Formats a +number+ into a US phone number (e.g., (555)
     # 123-9876). You can customize the format in the +options+ hash.
@@ -137,27 +38,7 @@ module ActiveSupport
     #   number_to_phone(1235551234, country_code: 1, extension: 1343, delimiter: '.')
     #   # => +1.123.555.1234 x 1343
     def number_to_phone(number, options = {})
-      return unless number
-      options = options.symbolize_keys
-
-      number       = number.to_s.strip
-      area_code    = options[:area_code]
-      delimiter    = options[:delimiter] || "-"
-      extension    = options[:extension]
-      country_code = options[:country_code]
-
-      if area_code
-        number.gsub!(/(\d{1,3})(\d{3})(\d{4}$)/,"(\\1) \\2#{delimiter}\\3")
-      else
-        number.gsub!(/(\d{0,3})(\d{3})(\d{4})$/,"\\1#{delimiter}\\2#{delimiter}\\3")
-        number.slice!(0, 1) if number.start_with?(delimiter) && !delimiter.blank?
-      end
-
-      str = ''
-      str << "+#{country_code}#{delimiter}" unless country_code.blank?
-      str << number
-      str << " x #{extension}" unless extension.blank?
-      str
+      NumberToPhoneConverter.new(number, options).execute
     end
 
     # Formats a +number+ into a currency string (e.g., $13.65). You
@@ -199,25 +80,7 @@ module ActiveSupport
     #   number_to_currency(1234567890.50, unit: '&pound;', separator: ',', delimiter: '', format: '%n %u')
     #   # => 1234567890,50 &pound;
     def number_to_currency(number, options = {})
-      return unless number
-      options = options.symbolize_keys
-
-      currency = i18n_format_options(options[:locale], :currency)
-      currency[:negative_format] ||= "-" + currency[:format] if currency[:format]
-
-      defaults  = default_format_options(:currency).merge!(currency)
-      defaults[:negative_format] = "-" + options[:format] if options[:format]
-      options   = defaults.merge!(options)
-
-      unit      = options.delete(:unit)
-      format    = options.delete(:format)
-
-      if number.to_f.phase != 0
-        format = options.delete(:negative_format)
-        number = number.respond_to?("abs") ? number.abs : number.sub(/^-/, '')
-      end
-
-      format.gsub('%n', self.number_to_rounded(number, options)).gsub('%u', unit)
+      NumberToCurrencyConverter.new(number, options).execute
     end
 
     # Formats a +number+ as a percentage string (e.g., 65%). You can
@@ -253,14 +116,7 @@ module ActiveSupport
     #   number_to_percentage('98a')                               # => 98a%
     #   number_to_percentage(100, format: '%n  %')                # => 100  %
     def number_to_percentage(number, options = {})
-      return unless number
-      options = options.symbolize_keys
-
-      defaults = format_options(options[:locale], :percentage)
-      options  = defaults.merge!(options)
-
-      format = options[:format] || "%n%"
-      format.gsub('%n', self.number_to_rounded(number, options))
+      NumberToPercentageConverter.new(number, options).execute
     end
 
     # Formats a +number+ with grouped thousands using +delimiter+
@@ -289,15 +145,7 @@ module ActiveSupport
     #   number_to_delimited(98765432.98, delimiter: ' ', separator: ',')
     #   # => 98 765 432,98
     def number_to_delimited(number, options = {})
-      options = options.symbolize_keys
-
-      return number unless valid_float?(number)
-
-      options = format_options(options[:locale]).merge!(options)
-
-      parts = number.to_s.split('.')
-      parts[0].gsub!(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1#{options[:delimiter]}")
-      parts.join(options[:separator])
+      NumberToDelimitedConverter.new(number, options).execute
     end
 
     # Formats a +number+ with the specified level of
@@ -340,39 +188,7 @@ module ActiveSupport
     #   number_to_rounded(1111.2345, precision: 2, separator: ',', delimiter: '.')
     #   # => 1.111,23
     def number_to_rounded(number, options = {})
-      return number unless valid_float?(number)
-      number  = Float(number)
-      options = options.symbolize_keys
-
-      defaults = format_options(options[:locale], :precision)
-      options  = defaults.merge!(options)
-
-      precision = options.delete :precision
-      significant = options.delete :significant
-      strip_insignificant_zeros = options.delete :strip_insignificant_zeros
-
-      if significant && precision > 0
-        if number == 0
-          digits, rounded_number = 1, 0
-        else
-          digits = (Math.log10(number.abs) + 1).floor
-          multiplier = 10 ** (digits - precision)
-          rounded_number = (BigDecimal.new(number.to_s) / BigDecimal.new(multiplier.to_f.to_s)).round.to_f * multiplier
-          digits = (Math.log10(rounded_number.abs) + 1).floor # After rounding, the number of digits may have changed
-        end
-        precision -= digits
-        precision = 0 if precision < 0 # don't let it be negative
-      else
-        rounded_number = BigDecimal.new(number.to_s).round(precision).to_f
-        rounded_number = rounded_number.abs if rounded_number.zero? # prevent showing negative zeros
-      end
-      formatted_number = self.number_to_delimited("%01.#{precision}f" % rounded_number, options)
-      if strip_insignificant_zeros
-        escaped_separator = Regexp.escape(options[:separator])
-        formatted_number.sub(/(#{escaped_separator})(\d*[1-9])?0+\z/, '\1\2').sub(/#{escaped_separator}\z/, '')
-      else
-        formatted_number
-      end
+      NumberToRoundedConverter.new(number, options).execute
     end
 
     # Formats the bytes in +number+ into a more understandable
@@ -420,36 +236,7 @@ module ActiveSupport
     #   number_to_human_size(1234567890123, precision: 5) # => "1.1229 TB"
     #   number_to_human_size(524288000, precision: 5)     # => "500 MB"
     def number_to_human_size(number, options = {})
-      options = options.symbolize_keys
-
-      return number unless valid_float?(number)
-      number = Float(number)
-
-      defaults = format_options(options[:locale], :human)
-      options  = defaults.merge!(options)
-
-      #for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
-      options[:strip_insignificant_zeros] = true if not options.key?(:strip_insignificant_zeros)
-
-      storage_units_format = translate_number_value_with_default('human.storage_units.format', :locale => options[:locale], :raise => true)
-
-      base = options[:prefix] == :si ? 1000 : 1024
-
-      if number.to_i < base
-        unit = translate_number_value_with_default('human.storage_units.units.byte', :locale => options[:locale], :count => number.to_i, :raise => true)
-        storage_units_format.gsub(/%n/, number.to_i.to_s).gsub(/%u/, unit)
-      else
-        max_exp  = STORAGE_UNITS.size - 1
-        exponent = (Math.log(number) / Math.log(base)).to_i # Convert to base
-        exponent = max_exp if exponent > max_exp # we need this to avoid overflow for the highest unit
-        number  /= base ** exponent
-
-        unit_key = STORAGE_UNITS[exponent]
-        unit = translate_number_value_with_default("human.storage_units.units.#{unit_key}", :locale => options[:locale], :count => number, :raise => true)
-
-        formatted_number = self.number_to_rounded(number, options)
-        storage_units_format.gsub(/%n/, formatted_number).gsub(/%u/, unit)
-      end
+      NumberToHumanSizeConverter.new(number, options).execute
     end
 
     # Pretty prints (formats and approximates) a number in a way it
@@ -550,88 +337,8 @@ module ActiveSupport
     #   number_to_human(1, units: :distance)                 # => "1 meter"
     #   number_to_human(0.34, units: :distance)              # => "34 centimeters"
     def number_to_human(number, options = {})
-      options = options.symbolize_keys
-
-      return number unless valid_float?(number)
-      number = Float(number)
-
-      defaults = format_options(options[:locale], :human)
-      options  = defaults.merge!(options)
-
-      #for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
-      options[:strip_insignificant_zeros] = true if not options.key?(:strip_insignificant_zeros)
-
-      inverted_du = DECIMAL_UNITS.invert
-
-      units = options.delete :units
-      unit_exponents = case units
-      when Hash
-        units
-      when String, Symbol
-        I18n.translate(:"#{units}", :locale => options[:locale], :raise => true)
-      when nil
-        translate_number_value_with_default("human.decimal_units.units", :locale => options[:locale], :raise => true)
-      else
-        raise ArgumentError, ":units must be a Hash or String translation scope."
-      end.keys.map{|e_name| inverted_du[e_name] }.sort_by{|e| -e}
-
-      number_exponent = number != 0 ? Math.log10(number.abs).floor : 0
-      display_exponent = unit_exponents.find{ |e| number_exponent >= e } || 0
-      number  /= 10 ** display_exponent
-
-      unit = case units
-      when Hash
-        units[DECIMAL_UNITS[display_exponent]] || ''
-      when String, Symbol
-        I18n.translate(:"#{units}.#{DECIMAL_UNITS[display_exponent]}", :locale => options[:locale], :count => number.to_i)
-      else
-        translate_number_value_with_default("human.decimal_units.units.#{DECIMAL_UNITS[display_exponent]}", :locale => options[:locale], :count => number.to_i)
-      end
-
-      decimal_format = options[:format] || translate_number_value_with_default('human.decimal_units.format', :locale => options[:locale])
-      formatted_number = self.number_to_rounded(number, options)
-      decimal_format.gsub(/%n/, formatted_number).gsub(/%u/, unit).strip
+      NumberToHumanConverter.new(number, options).execute
     end
 
-    def self.private_module_and_instance_method(method_name) #:nodoc:
-      private method_name
-      private_class_method method_name
-    end
-    private_class_method :private_module_and_instance_method
-
-    def format_options(locale, namespace = nil) #:nodoc:
-      default_format_options(namespace).merge!(i18n_format_options(locale, namespace))
-    end
-    private_module_and_instance_method :format_options
-
-    def default_format_options(namespace = nil) #:nodoc:
-      options = DEFAULTS[:format].dup
-      options.merge!(DEFAULTS[namespace][:format]) if namespace
-      options
-    end
-    private_module_and_instance_method :default_format_options
-
-    def i18n_format_options(locale, namespace = nil) #:nodoc:
-      options = I18n.translate(:'number.format', locale: locale, default: {}).dup
-      if namespace
-        options.merge!(I18n.translate(:"number.#{namespace}.format", locale: locale, default: {}))
-      end
-      options
-    end
-    private_module_and_instance_method :i18n_format_options
-
-    def translate_number_value_with_default(key, i18n_options = {}) #:nodoc:
-      default = key.split('.').reduce(DEFAULTS) { |defaults, k| defaults[k.to_sym] }
-
-      I18n.translate(key, { default: default, scope: :number }.merge!(i18n_options))
-    end
-    private_module_and_instance_method :translate_number_value_with_default
-
-    def valid_float?(number) #:nodoc:
-      Float(number)
-    rescue ArgumentError, TypeError
-      false
-    end
-    private_module_and_instance_method :valid_float?
   end
 end