Fallback to :en locale instead of handling a constant with defaults

Action Pack already comes with a default locale fine for :en, that is
always loaded. We can just fallback to this locale for defaults, if
values for the current locale cannot be found.

Closes #4420, #2802, #2890.

5 files changed, 177 insertions, 28 deletions

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 8bbf887876..ddd6a8b568 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,5 +1,10 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Add default values to all `ActiveSupport::NumberHelper` methods, to avoid
+    errors with empty locales or missing values.
+
+    *Carlos Antonio da Silva*
+
 *   ActiveSupport::JSON::Variable is deprecated. Define your own #as_json and
     #encode_json methods for custom JSON string literals.
 
diff --git a/activesupport/lib/active_support/locale/en.yml b/activesupport/lib/active_support/locale/en.yml
index 18c7d47026..f4900dc935 100644
--- a/activesupport/lib/active_support/locale/en.yml
+++ b/activesupport/lib/active_support/locale/en.yml
@@ -49,7 +49,7 @@ en:
       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 NumberHelper.number_to_currency()
     currency:
       format:
@@ -62,7 +62,7 @@ en:
         precision: 2
         significant: false
         strip_insignificant_zeros: false
-  
+
     # Used in NumberHelper.number_to_percentage()
     percentage:
       format:
@@ -73,7 +73,7 @@ en:
         # significant: false
         # strip_insignificant_zeros: false
         format: "%n%"
-  
+
     # Used in NumberHelper.number_to_rounded()
     precision:
       format:
@@ -83,7 +83,7 @@ en:
         # precision:
         # significant: false
         # strip_insignificant_zeros: false
-  
+
     # Used in NumberHelper.number_to_human_size() and NumberHelper.number_to_human()
     human:
       format:
@@ -131,5 +131,3 @@ en:
           billion: Billion
           trillion: Trillion
           quadrillion: Quadrillion
-  
-  
\ No newline at end of file
diff --git a/activesupport/lib/active_support/number_helper.rb b/activesupport/lib/active_support/number_helper.rb
index 99f6489adb..89a58f3701 100644
--- a/activesupport/lib/active_support/number_helper.rb
+++ b/activesupport/lib/active_support/number_helper.rb
@@ -7,12 +7,108 @@ module ActiveSupport
   module NumberHelper
     extend self
 
+    DEFAULTS = {
+      # Used in number_to_currency
+      currency: {
+        format: {
+          # Where is the currency sign? %u is the currency unit, %n the number (default: $5.00)
+          format: "%u%n",
+          unit: "$",
+          # These five are to override number.format and are optional
+          separator: ".",
+          delimiter: ",",
+          precision: 2,
+          significant: false,
+          strip_insignificant_zeros: false
+        }
+      },
+
+      # Used in number_to_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_percentage
+      percentage: {
+        format: {
+          delimiter: "",
+          format: "%n%"
+        }
+      },
+
+      # Used in number_to_rounded
+      precision: {
+        format: {
+          delimiter: ""
+        }
+      },
+
+      # 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 }
 
-    DEFAULT_CURRENCY_VALUES = { :format => "%u%n", :negative_format => "-%u%n", :unit => "$", :separator => ".", :delimiter => ",",
-                                :precision => 2, :significant => false, :strip_insignificant_zeros => false }
-
     STORAGE_UNITS = [:byte, :kb, :mb, :gb, :tb]
 
     # Formats a +number+ into a US phone number (e.g., (555)
@@ -106,10 +202,10 @@ module ActiveSupport
       return unless number
       options = options.symbolize_keys
 
-      currency = translations_for('currency', options[:locale])
+      currency = translations_for(:currency, options[:locale])
       currency[:negative_format] ||= "-" + currency[:format] if currency[:format]
 
-      defaults  = DEFAULT_CURRENCY_VALUES.merge(defaults_translations(options[:locale])).merge!(currency)
+      defaults  = defaults_translations(options[:locale]).merge(currency)
       defaults[:negative_format] = "-" + options[:format] if options[:format]
       options   = defaults.merge!(options)
 
@@ -160,7 +256,7 @@ module ActiveSupport
       return unless number
       options = options.symbolize_keys
 
-      defaults = format_translations('percentage', options[:locale])
+      defaults = format_translations(:percentage, options[:locale])
       options  = defaults.merge!(options)
 
       format = options[:format] || "%n%"
@@ -248,7 +344,7 @@ module ActiveSupport
       number  = Float(number)
       options = options.symbolize_keys
 
-      defaults = format_translations('precision', options[:locale])
+      defaults = format_translations(:precision, options[:locale])
       options  = defaults.merge!(options)
 
       precision = options.delete :precision
@@ -328,18 +424,18 @@ module ActiveSupport
       return number unless valid_float?(number)
       number = Float(number)
 
-      defaults = format_translations('human', options[:locale])
+      defaults = format_translations(:human, options[:locale])
       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 = I18n.translate(:'number.human.storage_units.format', :locale => options[:locale], :raise => true)
+      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 = I18n.translate(:'number.human.storage_units.units.byte', :locale => options[:locale], :count => number.to_i, :raise => true)
+        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
@@ -348,7 +444,7 @@ module ActiveSupport
         number  /= base ** exponent
 
         unit_key = STORAGE_UNITS[exponent]
-        unit = I18n.translate(:"number.human.storage_units.units.#{unit_key}", :locale => options[:locale], :count => number, :raise => true)
+        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)
@@ -458,7 +554,7 @@ module ActiveSupport
       return number unless valid_float?(number)
       number = Float(number)
 
-      defaults = format_translations('human', options[:locale])
+      defaults = format_translations(:human, options[:locale])
       options  = defaults.merge!(options)
 
       #for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
@@ -473,7 +569,7 @@ module ActiveSupport
       when String, Symbol
         I18n.translate(:"#{units}", :locale => options[:locale], :raise => true)
       when nil
-        I18n.translate(:"number.human.decimal_units.units", :locale => options[:locale], :raise => true)
+        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}
@@ -488,35 +584,50 @@ module ActiveSupport
       when String, Symbol
         I18n.translate(:"#{units}.#{DECIMAL_UNITS[display_exponent]}", :locale => options[:locale], :count => number.to_i)
       else
-        I18n.translate(:"number.human.decimal_units.units.#{DECIMAL_UNITS[display_exponent]}", :locale => options[:locale], :count => number.to_i)
+        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] || I18n.translate(:'number.human.decimal_units.format', :locale => options[:locale], :default => "%n %u")
+      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
     end
 
-    def self.private_module_and_instance_method(method_name)
+    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_translations(namespace, locale) #:nodoc:
-      defaults_translations(locale).merge(translations_for(namespace, locale))
+      defaults_translations(locale).merge!(translations_for(namespace, locale))
     end
     private_module_and_instance_method :format_translations
 
     def defaults_translations(locale) #:nodoc:
-      I18n.translate(:'number.format', :locale => locale, :default => {})
+      defaults      = DEFAULTS[:format].dup
+      i18n_defaults = I18n.translate(:'number.format', :locale => locale, :default => {})
+      defaults.merge!(i18n_defaults)
     end
     private_module_and_instance_method :defaults_translations
 
     def translations_for(namespace, locale) #:nodoc:
-      I18n.translate(:"number.#{namespace}.format", :locale => locale, :default => {})
+      defaults      = DEFAULTS[namespace][:format].dup
+      i18n_defaults = I18n.translate(:"number.#{namespace}.format", :locale => locale, :default => {})
+      defaults.merge!(i18n_defaults)
     end
     private_module_and_instance_method :translations_for
 
+    def translate_number_value_with_default(key, i18n_options = {})
+      defaults_keys = key.split('.')
+      default       = DEFAULTS
+      while default_key = defaults_keys.shift
+        default = default[default_key.to_sym]
+      end
+
+      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
diff --git a/activesupport/test/number_helper_i18n_test.rb b/activesupport/test/number_helper_i18n_test.rb
index e07198027b..4d0d5e8631 100644
--- a/activesupport/test/number_helper_i18n_test.rb
+++ b/activesupport/test/number_helper_i18n_test.rb
@@ -72,11 +72,24 @@ module ActiveSupport
       assert_equal("1.00", number_to_rounded(1.0, :locale => 'ts'))
     end
 
+    def test_number_with_i18n_precision_and_empty_i18n_store
+      I18n.backend.store_translations 'empty', {}
+
+      assert_equal("123456789.123", number_to_rounded(123456789.123456789, :locale => 'empty'))
+      assert_equal("1.000", number_to_rounded(1.0000, :locale => 'empty'))
+    end
+
     def test_number_with_i18n_delimiter
       #Delimiter "," and separator "."
       assert_equal("1,000,000.234", number_to_delimited(1000000.234, :locale => 'ts'))
     end
 
+    def test_number_with_i18n_delimiter_and_empty_i18n_store
+      I18n.backend.store_translations 'empty', {}
+
+      assert_equal("1,000,000.234", number_to_delimited(1000000.234, :locale => 'empty'))
+    end
+
     def test_number_to_i18n_percentage
       # to see if strip_insignificant_zeros is true
       assert_equal("1%", number_to_percentage(1, :locale => 'ts'))
@@ -86,12 +99,27 @@ module ActiveSupport
       assert_equal("12434%", number_to_percentage(12434, :locale => 'ts'))
     end
 
+    def test_number_to_i18n_percentage_and_empty_i18n_store
+      I18n.backend.store_translations 'empty', {}
+
+      assert_equal("1.000%", number_to_percentage(1, :locale => 'empty'))
+      assert_equal("1.243%", number_to_percentage(1.2434, :locale => 'empty'))
+      assert_equal("12434.000%", number_to_percentage(12434, :locale => 'empty'))
+    end
+
     def test_number_to_i18n_human_size
       #b for bytes and k for kbytes
       assert_equal("2 k", number_to_human_size(2048, :locale => 'ts'))
       assert_equal("42 b", number_to_human_size(42, :locale => 'ts'))
     end
 
+    def test_number_to_i18n_human_size_with_empty_i18n_store
+      I18n.backend.store_translations 'empty', {}
+
+      assert_equal("2 KB", number_to_human_size(2048, :locale => 'empty'))
+      assert_equal("42 Bytes", number_to_human_size(42, :locale => 'empty'))
+    end
+
     def test_number_to_human_with_default_translation_scope
       #Using t for thousand
       assert_equal "2 t", number_to_human(2000, :locale => 'ts')
@@ -106,6 +134,13 @@ module ActiveSupport
       assert_equal "2 Tens", number_to_human(20, :locale => 'ts')
     end
 
+    def test_number_to_human_with_empty_i18n_store
+      I18n.backend.store_translations 'empty', {}
+
+      assert_equal "2 Thousand", number_to_human(2000, :locale => 'empty')
+      assert_equal "1.23 Billion", number_to_human(1234567890, :locale => 'empty')
+    end
+
     def test_number_to_human_with_custom_translation_scope
       #Significant was set to true with precision 2, with custom translated units
       assert_equal "4.3 cm", number_to_human(0.0432, :locale => 'ts', :units => :custom_units_for_number_to_human)
diff --git a/activesupport/test/number_helper_test.rb b/activesupport/test/number_helper_test.rb
index 9b7d7f020c..f26d75edfb 100644
--- a/activesupport/test/number_helper_test.rb
+++ b/activesupport/test/number_helper_test.rb
@@ -4,7 +4,7 @@ require 'active_support/number_helper'
 module ActiveSupport
   module NumberHelper
     class NumberHelperTest < ActiveSupport::TestCase
-      
+
       class TestClassWithInstanceNumberHelpers
         include ActiveSupport::NumberHelper
       end
@@ -16,7 +16,7 @@ module ActiveSupport
       def setup
         @instance_with_helpers = TestClassWithInstanceNumberHelpers.new
       end
-  
+
       def kilobytes(number)
         number * 1024
       end
@@ -362,7 +362,7 @@ module ActiveSupport
           assert_equal "x", number_helper.number_to_human('x')
         end
       end
-  
+
       def test_extending_or_including_number_helper_correctly_hides_private_methods
         [@instance_with_helpers, TestClassWithClassNumberHelpers, ActiveSupport::NumberHelper].each do |number_helper|
           assert !number_helper.respond_to?(:valid_float?)