feature: removing nonprintable characters

https://jira.railsc.ru/browse/GOODS-1126

lib/string_tools/core_ext/string.rb

@@ -204,6 +204,30 @@ def mb_downcase
     mb_chars.downcase.to_s
   end
 
+  # Public: returns copy of string with all non-printable characters removed
+  #
+  # Examples
+  #
+  #   "q\uFFFEw\uFFFFe\uFFF0r\uFDD0t\uFDEFy".remove_nonprintable
+  #   # => "qwerty"
+  #
+  # Returns String
+  def remove_nonprintable
+    gsub(/[^[:print:]]/i, '')
+  end
+
+  # Public: removes all non-printable characters from string
+  #
+  # Examples
+  #
+  #   "q\uFFFEw\uFFFFe\uFFF0r\uFDD0t\uFDEFy".remove_nonprintable!
+  #   # => "qwerty"
+  #
+  # Returns String
+  def remove_nonprintable!
+    replace(remove_nonprintable)
+  end
+
   private
 
   def surround_with_ansi(ascii_seq)

spec/string_spec.rb

@@ -6,4 +6,16 @@
   describe '#mb_downcase' do
     it { expect("Кириллица".mb_downcase).to eq("кириллица") }
   end
+
+  describe '#remove_nonprintable' do
+    let(:string) { "\uFDD1string\uFFFE \uFFFFwith\uFDEF weird characters\uFDD0" }
+
+    it { expect(string.remove_nonprintable).to eq 'string with weird characters' }
+  end
+
+  describe '#remove_nonprintable!' do
+    let(:string) { "\uFDD1string\uFFFE \uFFFFwith\uFDEF weird characters\uFDD0" }
+
+    it { expect { string.remove_nonprintable! }.to change { string }.to('string with weird characters') }
+  end
 end