Ruby string encoding defaults to UTF-8, but String#strip doesn't alter its definition of whitespace to match the encoding, it's always defined as: '\x00\t\n\v\f\r '. This does not include unicode whitespace no matter the string's encoding, see Ruby Regexp Character Classes for more info. It would appear that [[:space:]] does in fact include unic…

strip_harder.rb

# This was probably encountered and overcome a long time ago, but I ran into it in my own Ruby dealings and thought maybe it could be an issue elsewhere:
 
  # Ruby string encoding defaults to UTF-8, but String#strip doesn't alter its
  #   definition of whitespace to match the encoding
  #   https://ruby-doc.org/core-2.6.8/String.html#method-i-strip
  #   String#strip removes lead/trail whitespace defined as: '\x00\t\n\v\f\r '
  #   null, horiz tab, line feed, vert tab, form feed, carriage return, & space
  #   This does not include unicode whitespace no matter the string's encoding,
  #   see Regexp for more info
  #  https://ruby-doc.org/core-2.6.8/Regexp.html#class-Regexp-label-Character+Classes
  #  It would appear that [[:space:]] does in fact include unicode whitespace
  #  (at least) when the string encoding is UTF-8. Unicode has all sorts of
  #  whitespace chars that you've probably never heard of like ogham space mark
  #  https://en.wikipedia.org/wiki/Whitespace_character#Unicode

  STRIP_REGEX = /(?:\A[[:space:]]+|[[:space:]]+\Z)/
 
  def strip_harder!(str)
    str.gsub!(STRIP_REGEX, '')
  end
 
  def strip_harder(str)
    str.gsub(STRIP_REGEX, '')
  end
  
s = "https://www.app.moc/support/security-bulletins.html\u00a0"
#=> "https://www.app.moc/support/security-bulletins.html "
strip_harder(s)
#=> "https://www.app.moc/support/security-bulletins.html"