Recursively rename folders based on contents in Ruby - ruby

Question

I have a collection of folders (within a folder) that all need to be renamed based on their contents.
Specifically, I'd like to rename "/working_directory/my_folder/my_file.extension" to /working_directory/my_file/my_file.extension"
There are a few other files within /my_folder/. How might I recursively do this using ruby?
I'm new to ruby and programming, I have so tried to just extract the file names, but have not have much luck. The attempt at itterating through the folders. This will cycle through /working_directory/ every time Find.find is called. The intent is to search /working_directory/my_folder/ only for the file with the .fls extension.
require 'find'
Path = "/working_directory/"
Dir.foreach(Path) do |file|
puts file
new_dir = Path+file
puts new_dir
Find.find(new_dir) do |i| # this is intended to by /working_directory/my_folder/
fls_file << i if i =~ /.*\.fls$/
puts fls_file
end
end

Answer 1

Assuming, the my_file is to be chosen by extension, one might do:
Dir["/working_directory/**/*"].select do |dir_or_file|
File.directory? dir_or_file # select only directories, recursively
end.inject({}) do |memo, dir|
new_name = Dir["#{dir}/*.extension"].to_a
unless new_name.size == 1 # check if the folder contains only one proper file
puts "Multiple/No choices; can not rename dir [#{dir}] ⇒ skipping..."
next memo # skip if no condition met
end
my_file = new_name.first[/[^\/]+(?=\.extension\z)/] # get my_name
memo[dir] = dir.gsub /[^\/]+(?=\/#{myfile}\.extension\z)/, my_file
memo
end.each do |old, neu|
# dry run to make sure everything is OK
puts "Gonna rename #{old} to #{neu}"
# uncomment the lines below as you are certain the code works properly
# neu_folder = neu[/(.*?)([^\/]+\z)/, 1]
# FileUtils.mkdir neu_folder unless File.exist? neu_folder
# FileUtils.mv old, neu # rename
end
The rename is done after the main processing for the sake of previous iterator consistency, probably in this case it might be done in the previous loop, instead of injecting old: neu pairs into hash and iterating it later.
We are heavily using string parsing with regexps here.
my_file = new_name.first[/[^\/]+(?=\.extension\z)/] # get my_name
this line gets a new folder name by parsing a tail of the string, containing no slashes and trailing with '.extension\z' (see positive lookahead.)
memo[dir] = dir.gsub /[^\/]+(?=\/#{myfile}\.extension\z)/, my_file
This line assigns a new element on an accumulator hash, substituting the old folder name with the new one.