Remove tough to grasp -1 + 1 = 0 from String#to

In case a negative position is provided that exceeds the size of the
string, we're relying on -1 returned from max to get 0 length by + 1
and let [] with a 0 length returning "" for us.

E.g. "hello".to(-7), where -7 + 5 size = -2. That's
lower than -1, so we use -1 instead and + 1 would turn it into 0.

Instead allow outer bounds access and always return "".

2 files changed, 4 insertions, 2 deletions

diff --git a/activesupport/lib/active_support/core_ext/string/access.rb b/activesupport/lib/active_support/core_ext/string/access.rb
index 4894193665..4f70e7f5fc 100644
--- a/activesupport/lib/active_support/core_ext/string/access.rb
+++ b/activesupport/lib/active_support/core_ext/string/access.rb
@@ -61,8 +61,8 @@ class String
   #   str.from(0).to(-1) # => "hello"
   #   str.from(1).to(-2) # => "ell"
   def to(position)
-    position = [position + length, -1].max if position < 0
-    self[0, position + 1]
+    position += size if position < 0
+    self[0, position + 1].to_s
   end
 
   # Returns the first character. If a limit is supplied, returns a substring
diff --git a/activesupport/test/core_ext/string_ext_test.rb b/activesupport/test/core_ext/string_ext_test.rb
index c5a000b67a..b1ab9533e7 100644
--- a/activesupport/test/core_ext/string_ext_test.rb
+++ b/activesupport/test/core_ext/string_ext_test.rb
@@ -455,6 +455,8 @@ class StringAccessTest < ActiveSupport::TestCase
 
   test "#to with negative Integer, position is counted from the end" do
     assert_equal "hell", "hello".to(-2)
+    assert_equal "h", "hello".to(-5)
+    assert_equal "", "hello".to(-7)
   end
 
   test "#from and #to can be combined" do