Merge pull request #20737 from gouravtiwari/multibyte_chars_slice_fix

Fixed multibyte-chars slice! behavior to return nil for out-of-bound
parameters

1 files changed, 12 insertions, 0 deletions

diff --git a/activesupport/test/multibyte_chars_test.rb b/activesupport/test/multibyte_chars_test.rb
index e1c4b705f8..8d4d9d736c 100644
--- a/activesupport/test/multibyte_chars_test.rb
+++ b/activesupport/test/multibyte_chars_test.rb
@@ -413,12 +413,24 @@ class MultibyteCharsUTF8BehaviourTest < ActiveSupport::TestCase
     assert_equal 'にち', @chars.slice!(1..2)
   end
 
+  def test_slice_bang_returns_nil_on_out_of_bound_arguments
+    assert_equal nil, @chars.mb_chars.slice!(9..10)
+  end
+
   def test_slice_bang_removes_the_slice_from_the_receiver
     chars = 'úüù'.mb_chars
     chars.slice!(0,2)
     assert_equal 'ù', chars
   end
 
+  def test_slice_bang_returns_nil_and_does_not_modify_receiver_if_out_of_bounds
+    string = 'úüù'
+    chars = string.mb_chars
+    assert_nil chars.slice!(4, 5)
+    assert_equal 'úüù', chars
+    assert_equal 'úüù', string
+  end
+
   def test_slice_should_throw_exceptions_on_invalid_arguments
     assert_raise(TypeError) { @chars.slice(2..3, 1) }
     assert_raise(TypeError) { @chars.slice(1, 2..3) }