I really have problem reading code with spaces, so I use the visual studio code editor to indent codes from spaces to tabs before I read them.

But the problem is rails has a lot of files, I have to do the same operation repetitively. So, I want to use Dir.glob to iterate over all of them and covert spaces to tabs and overwrite those files. It is a terrible idea, but still...

Currently my String#spaces_to_tabs() method looks like this:

Code

# A method that works for now...
String.define_method(:spaces_to_tabs) do
    each_line.map do |x|
        match = x.match(/^([^\S\t\n\r]*)/)[0]
        m_len = match.length
        (m_len > 0 && m_len % 2 == 0) ? ?\t * (m_len / 2) + x[m_len .. -1] : x
    end.join
end

Which kind of works

Here's a test:

# Put some content that will get converted to space
content = <<~EOF << '# Hello!'
  def x
    'Hello World'
  end

  p x

  module X
    refine Array do
      define_method(:tally2) do
        uniq.reduce({}) { |h, x| h.merge!( x => count(x) ) }
      end
    end
  end

  using X
  [1, 2, 3, 4, 4, 4,?a, ?b, ?a].tally2
  p [1, 2, 3, 4, 4, 4,?a, ?b, ?a].tally2
  \r\r\t\t # Some invalid content
EOF

puts content.spaces_to_tabs

Output:

def x
    'Hello World'
end

p x

module X
    refine Array do
        define_method(:tally2) do
            uniq.reduce({}) { |h, x| h.merge!( x => count(x) ) }
        end
    end
end

using X
[1, 2, 3, 4, 4, 4,?a, ?b, ?a].tally2
p [1, 2, 3, 4, 4, 4,?a, ?b, ?a].tally2
         # Some invalid content
# Hello!

Currently it does not:

1. Affect white-spaces (\t, \r, \n) other than spaces.
2. Affect the output of code, only converts spaces to tabs.

I can't use my editor because:

1. With Dir.glob (not included in this example), I can iterate over only .rb, .js, .erb, .html, .css, and .scss files.

Also, this is slow, but I can have at most 1000 files (above extensions) with 1000 lines of code for each file, but that's max, and not too practical, I generally have < 100 files with a couple of hundred lines of code. The code can take 10 seconds, which is not a problem here, since I need to run the code once for a project...

Is there a better way to do it?

Edit

Here's the full code with globbing for converting all major files in rails:

#!/usr/bin/ruby -w
String.define_method(:bold) { "\e[1m#{self}" }

String.define_method(:spaces_to_tabs) do
    each_line.map do |x|
        match = x.match(/^([^\S\t\n\r]*)/)[0]
        m_len = match.length
        (m_len > 0 && m_len % 2 == 0) ? ?\t * (m_len / 2) + x[m_len .. -1] : x
    end.join
end

GREEN = "\e[38;2;85;160;10m".freeze
BLUE = "\e[38;2;0;125;255m".freeze
TURQUOISE = "\e[38;2;60;230;180m".freeze
RESET = "\e[0m".freeze
BLINK = "\e[5m".freeze

dry_test = ARGV.any? { |x| x[/^\-(\-dry\-test|d)$/] }
puts "#{TURQUOISE.bold}:: Info:#{RESET}#{TURQUOISE} Running in Dry Test mode. Files will not be changed.#{RESET}\n\n" if dry_test

Dir.glob("{app,config,db,lib,public}/**/**.{rb,erb,js,css,scss,html}").map do |y|
    if File.file?(y) && File.readable?(y)
        read = IO.read(y)
        converted = read.spaces_to_tabs

        unless read == converted
            puts "#{BLINK}#{BLUE.bold}:: Converting#{RESET}#{GREEN} indentation to tabs of #{y}#{RESET}"
            IO.write(y, converted) unless dry_test
        end
    end
end