1 files changed, 34 insertions, 0 deletions
diff --git a/activesupport/test/multibyte_proxy_test.rb b/activesupport/test/multibyte_proxy_test.rb
new file mode 100644
index 0000000000..d8ffd7ca9c
--- /dev/null
+++ b/activesupport/test/multibyte_proxy_test.rb
@@ -0,0 +1,34 @@
+# encoding: utf-8
+
+require 'abstract_unit'
+
+class MultibyteProxyText < ActiveSupport::TestCase
+  class AsciiOnlyEncoder
+    attr_reader :wrapped_string
+    alias to_s wrapped_string
+
+    def initialize(string)
+      @wrapped_string = string.gsub(/[^\u0000-\u007F]/, '?')
+    end
+  end
+
+  def with_custom_encoder(encoder)
+    original_proxy_class = ActiveSupport::Multibyte.proxy_class
+
+    begin
+      ActiveSupport::Multibyte.proxy_class = encoder
+
+      yield
+    ensure
+      ActiveSupport::Multibyte.proxy_class = original_proxy_class
+    end
+  end
+
+  test "custom multibyte encoder" do
+    with_custom_encoder(AsciiOnlyEncoder) do
+      assert_equal "s?me string 123", "søme string 123".mb_chars.to_s
+    end
+
+    assert_equal "søme string 123", "søme string 123".mb_chars.to_s
+  end
+end