Parameterize with options to preserve case of string

Added test cases

Using kwargs instead of three seperate functions

Updated parameterize in transliterate.rb

Updated parameterize in transliterate.rb

Added deprecation warnings and updating RDoc+Guide

Misspelled separtor. Fixed.

Deprecated test cases and added support to parameterize with keyword parameters

Squashing commits.

Fixed test cases and added deprecated test cases

Small changes to Gemfile.lock and CHANGELOG

Update Gemfile.lock

2 files changed, 43 insertions, 10 deletions

diff --git a/activesupport/lib/active_support/core_ext/string/inflections.rb b/activesupport/lib/active_support/core_ext/string/inflections.rb
index b2e713077c..cc71b8155d 100644
--- a/activesupport/lib/active_support/core_ext/string/inflections.rb
+++ b/activesupport/lib/active_support/core_ext/string/inflections.rb
@@ -164,8 +164,26 @@ class String
   #
   #   <%= link_to(@person.name, person_path) %>
   #   # => <a href="/person/1-donald-e-knuth">Donald E. Knuth</a>
-  def parameterize(sep = '-'.freeze)
-    ActiveSupport::Inflector.parameterize(self, sep)
+  #   
+  # To preserve the case of the characters in a string, use the `preserve_case` argument.
+  #
+  #   class Person
+  #     def to_param
+  #       "#{id}-#{name.parameterize(preserve_case: true)}"
+  #     end
+  #   end
+  #
+  #   @person = Person.find(1)
+  #   # => #<Person id: 1, name: "Donald E. Knuth">
+  #
+  #   <%= link_to(@person.name, person_path) %>
+  #   # => <a href="/person/1-Donald-E-Knuth">Donald E. Knuth</a>
+  def parameterize(sep = :unused, separator: '-', preserve_case: false)
+    unless sep == :unused
+      ActiveSupport::Deprecation.warn("Passing the separator argument as a positional parameter is deprecated and will soon be removed. Use `separator: '#{sep}'` instead.")
+      separator = sep
+    end
+    ActiveSupport::Inflector.parameterize(self, separator: separator, preserve_case: preserve_case)
   end
 
   # Creates the name of a table like Rails does for models to table names. This method
diff --git a/activesupport/lib/active_support/inflector/transliterate.rb b/activesupport/lib/active_support/inflector/transliterate.rb
index 103207fb63..871cfb8a72 100644
--- a/activesupport/lib/active_support/inflector/transliterate.rb
+++ b/activesupport/lib/active_support/inflector/transliterate.rb
@@ -68,29 +68,44 @@ module ActiveSupport
     #
     #   parameterize("Donald E. Knuth") # => "donald-e-knuth"
     #   parameterize("^trés|Jolie-- ")  # => "tres-jolie"
-    def parameterize(string, sep = '-')
+    #
+    # To use a custom separator, override the `separator` argument.
+    #
+    #  parameterize("Donald E. Knuth", separator: '_') # => "donald_e_knuth"
+    #  parameterize("^trés|Jolie-- ", separator: '_')  # => "tres_jolie"
+    #
+    # To preserve the case of the characters in a string, use the `preserve_case` argument.
+    #
+    #   parameterize("Donald E. Knuth", preserve_case: true) # => "Donald-E-Knuth"
+    #   parameterize("^trés|Jolie-- ", preserve_case: true) # => "tres-Jolie"
+    #
+    def parameterize(string, sep = :unused, separator: '-', preserve_case: false)
+      unless sep == :unused
+        ActiveSupport::Deprecation.warn("Passing the separator argument as a positional parameter is deprecated and will soon be removed. Use `separator: '#{sep}'` instead.")
+        separator = sep
+      end
       # Replace accented chars with their ASCII equivalents.
       parameterized_string = transliterate(string)
 
       # Turn unwanted chars into the separator.
-      parameterized_string.gsub!(/[^a-z0-9\-_]+/i, sep)
+      parameterized_string.gsub!(/[^a-z0-9\-_]+/i, separator)
 
-      unless sep.nil? || sep.empty?
-        if sep == "-".freeze
+      unless separator.nil? || separator.empty?
+        if separator == "-".freeze
           re_duplicate_separator        = /-{2,}/
           re_leading_trailing_separator = /^-|-$/i
         else
-          re_sep = Regexp.escape(sep)
+          re_sep = Regexp.escape(separator)
           re_duplicate_separator        = /#{re_sep}{2,}/
           re_leading_trailing_separator = /^#{re_sep}|#{re_sep}$/i
         end
         # No more than one of the separator in a row.
-        parameterized_string.gsub!(re_duplicate_separator, sep)
+        parameterized_string.gsub!(re_duplicate_separator, separator)
         # Remove leading/trailing separator.
         parameterized_string.gsub!(re_leading_trailing_separator, ''.freeze)
       end
-
-      parameterized_string.downcase!
+      
+      parameterized_string.downcase! unless preserve_case
       parameterized_string
     end
   end