Make UTF-8 string requirement explicit for `transliterate`

It's noted in #34062 that String#parameterize will raise an `Encoding::CompatibilityError` if the string is not UTF-8 encoded. The error is raised as a result of passing the string to `.unicode_normalize`.

This PR raises a higher level `ArgumentError` if the provided string is not UTF-8 and updates documentation to note the encoding requirement.

1 files changed, 8 insertions, 0 deletions

diff --git a/activesupport/test/transliterate_test.rb b/activesupport/test/transliterate_test.rb
index 9e29a93ea0..525b4a8559 100644
--- a/activesupport/test/transliterate_test.rb
+++ b/activesupport/test/transliterate_test.rb
@@ -57,4 +57,12 @@ class TransliterateTest < ActiveSupport::TestCase
     end
     assert_equal "Can only transliterate strings. Received Object", exception.message
   end
+
+  def test_transliterate_handles_non_unicode_strings
+    ascii_8bit_string = "A".b
+    exception = assert_raises ArgumentError do
+      assert_equal "A", ActiveSupport::Inflector.transliterate(ascii_8bit_string)
+    end
+    assert_equal "Can only transliterate UTF-8 strings. Received string with encoding ASCII-8BIT", exception.message
+  end
 end