Truncate :auto line breaks when using UTF-8 Ellipsis

[brand-it]

The truncate auto does not seem to take into account that you are adding on extra ellipsis characters to the length of the string. I think this is only a UTF-8 Safe string issue but here is the code I created to create the issue. Also this issue comes up in the capistrano gem when deploying however that is a bit harder to document so I recreted the issue based off the code located here.

class Test
  require "io/console"
  def self.run
    console_width = IO.console.winsize.last
    ellipsis = '…' # UTF-8 Support only
    string_large_2 = (console_width + 2).times.map { 's' }.join
    string_large_1 = (console_width + 1).times.map { 's' }.join
    string_control = console_width.times.map { 's' }.join
    string_small_1 = (console_width - 1).times.map { 's' }.join
    string_small_2 = (console_width - 2).times.map { 's' }.join

    console_width -= ellipsis.length # remove the ellipsis from the width

    string_large_2.chop! while string_large_2.length > console_width
    string_large_1.chop! while string_large_1.length > console_width
    string_control.chop! while string_control.length > console_width
    string_small_1.chop! while string_small_1.length > console_width
    string_small_2.chop! while string_small_2.length > console_width


    puts '-------------- Results -------------------'
    puts 'string_large_2'
    puts string_large_2 + ellipsis
    puts 'string_large_1'
    puts string_large_1 + ellipsis
    puts 'string_control'
    puts string_control + ellipsis
    puts 'string_small_1'
    puts string_small_1 + ellipsis
    puts 'string_small_2'
    puts string_small_2 + ellipsis
    puts '-------------- End Results ---------------'
  end
end

If you run this in irb it should result in the … breaking to the new line in all the cases except string_small_2, which is under the width of the console.

The solution seam to be that by subtracting one from the lenght on this line https://github.com/mattbrictson/airbrussh/blob/master/lib/airbrussh/console.rb#L46 it will correclty display issues.

[mattbrictson]

Hmm, I don't see that problem when running your test code on my terminal (Mac):

Do you think it is something specific to your terminal that it does something weird with the UTF-8 ellipsis? I'm wondering what Airbrussh can do in this case. Subtracting 1 seems like a brute force fix. Perhaps better would be to detect the terminal and apply the workaround only if needed?

[brand-it]

Oh interesting so this error only happens in iTerm and not in Terminal. This is only happening on iTerm.

[brand-it]

I can't find any font difference between the two that I am using or really anything that would change the result but yet here it is.

[brand-it]

Found the problem it was a setting under text settings.

[brand-it]

don't know why that was on but that is the reason for the length issues in iTerm