3 files changed, 90 insertions, 4 deletions

diff --git a/activesupport/test/core_ext/string_ext_test.rb b/activesupport/test/core_ext/string_ext_test.rb
index 9cc7bb1a77..2e69816364 100644
--- a/activesupport/test/core_ext/string_ext_test.rb
+++ b/activesupport/test/core_ext/string_ext_test.rb
@@ -143,15 +143,49 @@ class StringInflectionsTest < ActiveSupport::TestCase
     end
   end
 
+  def test_string_parameterized_normal_preserve_case
+    StringToParameterizedPreserveCase.each do |normal, slugged|
+      assert_equal(normal.parameterize(preserve_case: true), slugged)
+    end
+  end
+
   def test_string_parameterized_no_separator
     StringToParameterizeWithNoSeparator.each do |normal, slugged|
-      assert_equal(normal.parameterize(''), slugged)
+      assert_equal(normal.parameterize(separator: ''), slugged)
+    end
+  end
+
+  def test_string_parameterized_no_separator_deprecated
+    StringToParameterizeWithNoSeparator.each do |normal, slugged|
+      assert_deprecated(/Passing the separator argument as a positional parameter is deprecated and will soon be removed. Use `separator: ''` instead./i) do
+        assert_equal(normal.parameterize(''), slugged)
+      end
+    end
+  end
+
+  def test_string_parameterized_no_separator_preserve_case
+    StringToParameterizePreserveCaseWithNoSeparator.each do |normal, slugged|
+      assert_equal(normal.parameterize(separator: '', preserve_case: true), slugged)
     end
   end
 
   def test_string_parameterized_underscore
     StringToParameterizeWithUnderscore.each do |normal, slugged|
-      assert_equal(normal.parameterize('_'), slugged)
+      assert_equal(normal.parameterize(separator: '_'), slugged)
+    end
+  end
+
+  def test_string_parameterized_underscore_deprecated
+    StringToParameterizeWithUnderscore.each do |normal, slugged|
+      assert_deprecated(/Passing the separator argument as a positional parameter is deprecated and will soon be removed. Use `separator: '_'` instead./i) do
+        assert_equal(normal.parameterize('_'), slugged)
+      end
+    end
+  end
+
+  def test_string_parameterized_underscore_preserve_case
+    StringToParameterizePreserceCaseWithUnderscore.each do |normal, slugged|
+      assert_equal(normal.parameterize(separator: '_', preserve_case: true), slugged)
     end
   end
 
diff --git a/activesupport/test/inflector_test.rb b/activesupport/test/inflector_test.rb
index a0764f6d6b..06cd41c86d 100644
--- a/activesupport/test/inflector_test.rb
+++ b/activesupport/test/inflector_test.rb
@@ -269,14 +269,32 @@ class InflectorTest < ActiveSupport::TestCase
   def test_parameterize_with_custom_separator
     jruby_skip "UTF-8 to UTF8-MAC Converter is unavailable"
     StringToParameterizeWithUnderscore.each do |some_string, parameterized_string|
-      assert_equal(parameterized_string, ActiveSupport::Inflector.parameterize(some_string, '_'))
+      assert_equal(parameterized_string, ActiveSupport::Inflector.parameterize(some_string, separator: '_'))
+    end
+  end
+
+  def test_parameterize_with_custom_separator_deprecated
+    jruby_skip "UTF-8 to UTF8-MAC Converter is unavailable"
+    StringToParameterizeWithUnderscore.each do |some_string, parameterized_string|
+      assert_deprecated(/Passing the separator argument as a positional parameter is deprecated and will soon be removed. Use `separator: '_'` instead./i) do
+        assert_equal(parameterized_string, ActiveSupport::Inflector.parameterize(some_string, '_'))
+      end
     end
   end
 
   def test_parameterize_with_multi_character_separator
     jruby_skip "UTF-8 to UTF8-MAC Converter is unavailable"
     StringToParameterized.each do |some_string, parameterized_string|
-      assert_equal(parameterized_string.gsub('-', '__sep__'), ActiveSupport::Inflector.parameterize(some_string, '__sep__'))
+      assert_equal(parameterized_string.gsub('-', '__sep__'), ActiveSupport::Inflector.parameterize(some_string, separator: '__sep__'))
+    end
+  end
+
+  def test_parameterize_with_multi_character_separator_deprecated
+    jruby_skip "UTF-8 to UTF8-MAC Converter is unavailable"
+    StringToParameterized.each do |some_string, parameterized_string|
+      assert_deprecated(/Passing the separator argument as a positional parameter is deprecated and will soon be removed. Use `separator: '__sep__'` instead./i) do
+        assert_equal(parameterized_string.gsub('-', '__sep__'), ActiveSupport::Inflector.parameterize(some_string, '__sep__'))
+      end
     end
   end
 
diff --git a/activesupport/test/inflector_test_cases.rb b/activesupport/test/inflector_test_cases.rb
index e6898658b5..14fe97a986 100644
--- a/activesupport/test/inflector_test_cases.rb
+++ b/activesupport/test/inflector_test_cases.rb
@@ -174,6 +174,17 @@ module InflectorTestCases
     "Test with malformed utf8 \251"       => "test-with-malformed-utf8"
   }
 
+  StringToParameterizedPreserveCase = {
+    "Donald E. Knuth"                     => "Donald-E-Knuth",
+    "Random text with *(bad)* characters" => "Random-text-with-bad-characters", 
+    "Allow_Under_Scores"                  => "Allow_Under_Scores", 
+    "Trailing bad characters!@#"          => "Trailing-bad-characters", 
+    "!@#Leading bad characters"           => "Leading-bad-characters", 
+    "Squeeze   separators"                => "Squeeze-separators", 
+    "Test with + sign"                    => "Test-with-sign", 
+    "Test with malformed utf8 \xA9"       => "Test-with-malformed-utf8"
+  }
+
   StringToParameterizeWithNoSeparator = {
     "Donald E. Knuth"                     => "donaldeknuth",
     "With-some-dashes"                    => "with-some-dashes",
@@ -185,6 +196,17 @@ module InflectorTestCases
     "Test with malformed utf8 \251"       => "testwithmalformedutf8"
   }
 
+  StringToParameterizePreserveCaseWithNoSeparator = {
+    "Donald E. Knuth"                     => "DonaldEKnuth",
+    "With-some-dashes"                    => "With-some-dashes",
+    "Random text with *(bad)* characters" => "Randomtextwithbadcharacters", 
+    "Trailing bad characters!@#"          => "Trailingbadcharacters", 
+    "!@#Leading bad characters"           => "Leadingbadcharacters", 
+    "Squeeze   separators"                => "Squeezeseparators", 
+    "Test with + sign"                    => "Testwithsign", 
+    "Test with malformed utf8 \xA9"       => "Testwithmalformedutf8"
+  }
+
   StringToParameterizeWithUnderscore = {
     "Donald E. Knuth"                     => "donald_e_knuth",
     "Random text with *(bad)* characters" => "random_text_with_bad_characters",
@@ -197,6 +219,18 @@ module InflectorTestCases
     "Test with malformed utf8 \251"       => "test_with_malformed_utf8"
   }
 
+  StringToParameterizePreserceCaseWithUnderscore = {
+    "Donald E. Knuth"                     => "Donald_E_Knuth", 
+    "Random text with *(bad)* characters" => "Random_text_with_bad_characters",
+    "With-some-dashes"                    => "With-some-dashes", 
+    "Allow_Under_Scores"                  => "Allow_Under_Scores", 
+    "Trailing bad characters!@#"          => "Trailing_bad_characters", 
+    "!@#Leading bad characters"           => "Leading_bad_characters", 
+    "Squeeze   separators"                => "Squeeze_separators", 
+    "Test with + sign"                    => "Test_with_sign", 
+    "Test with malformed utf8 \xA9"       => "Test_with_malformed_utf8"
+  }
+
   StringToParameterizedAndNormalized = {
     "Malmö"                               => "malmo",
     "Garçons"                             => "garcons",