Fix bug with parametrize when `locale` is passed

Also add tests for parametrize and transliterate

activesupport/lib/active_support/inflector/transliterate.rb

@@ -90,7 +90,7 @@ module ActiveSupport
     #
     def parameterize(string, separator: "-", preserve_case: false, locale: nil)
       # Replace accented chars with their ASCII equivalents.
-      parameterized_string = transliterate(string, locale)
+      parameterized_string = transliterate(string, locale: locale)
 
       # Turn unwanted chars into the separator.
       parameterized_string.gsub!(/[^a-z0-9\-_]+/i, separator)

activesupport/test/core_ext/string_ext_test.rb

@@ -206,6 +206,12 @@ class StringInflectionsTest < ActiveSupport::TestCase
     end
   end
 
+  def test_parameterize_with_locale
+    word = "Fünf autos"
+    I18n.backend.store_translations(:de, i18n: { transliterate: { rule: { "ü" => "ue" } } })
+    assert_equal("fuenf-autos", word.parameterize(locale: :de))
+  end
+
   def test_humanize
     UnderscoreToHuman.each do |underscore, human|
       assert_equal(human, underscore.humanize)

activesupport/test/inflector_test.rb

@@ -304,6 +304,12 @@ class InflectorTest < ActiveSupport::TestCase
     end
   end
 
+  def test_parameterize_with_locale
+    word = "Fünf autos"
+    I18n.backend.store_translations(:de, i18n: { transliterate: { rule: { "ü" => "ue" } } })
+    assert_equal("fuenf-autos", ActiveSupport::Inflector.parameterize(word, locale: :de))
+  end
+
   def test_classify
     ClassNameToTableName.each do |class_name, table_name|
       assert_equal(class_name, ActiveSupport::Inflector.classify(table_name))

activesupport/test/transliterate_test.rb

@@ -30,6 +30,12 @@ class TransliterateTest < ActiveSupport::TestCase
     I18n.locale = default_locale
   end
 
+  def test_transliterate_respects_the_locale_argument
+    char = [117, 776].pack("U*") # "ü" as ASCII "u" plus COMBINING DIAERESIS
+    I18n.backend.store_translations(:de, i18n: { transliterate: { rule: { "ü" => "ue" } } })
+    assert_equal "ue", ActiveSupport::Inflector.transliterate(char, locale: :de)
+  end
+
   def test_transliterate_should_allow_a_custom_replacement_char
     assert_equal "a*b", ActiveSupport::Inflector.transliterate("a索b", "*")
   end