Ocran requires and extends Pathname with RefinePathname

This is necessary to refactor the code to be robust and secure by utilizing the essential functionalities for path manipulation provided by Pathname.
Pathname is a standard library that, starting from Ruby 3.0, can handle Windows absolute paths.
Reference: https://github.com/ruby/ruby/blob/ruby_3_0/ext/pathname/lib/pathname.rb

bin/ocran

@@ -1,33 +1,12 @@
 #!/usr/bin/env ruby
 # -*- ruby -*-
 # encoding: UTF-8
+require "pathname"
 
 module Ocran
-  # Path handling class. Ruby's Pathname class is not used because it
-  # is case sensitive and doesn't handle paths with mixed path
-  # separators.
-  class Pathname
-    def Pathname.pwd
-      Pathname.new(Dir.pwd)
-    end
-
-    def Pathname.glob(pattern, flags = 0)
-      if block_given?
-        Dir.glob(pattern, flags) { |s| yield Pathname.new(s) }
-      else
-        ary = Dir.glob(pattern, flags)
-        ary.map! { |s| Pathname.new(s) }
-        ary
-      end
-    end
-
-    SEPARATOR_PAT = /[#{Regexp.quote File::ALT_SEPARATOR.to_s}#{Regexp.quote File::SEPARATOR}]/
-    ABSOLUTE_PAT = /\A([A-Z]:)?#{SEPARATOR_PAT}/i
-
-    def initialize(path)
-      @path = path
-    end
-
+  # The Pathname class in Ruby is modified to handle mixed path separators and
+  # to be case-insensitive.
+  module RefinePathname
     # Compares two paths for equality based on the case sensitivity of the
     # Ruby execution environment's file system.
     # If the file system is case-insensitive, it performs a case-insensitive
@@ -64,38 +43,6 @@ module Ocran
     alias == eql?
     alias === eql?
 
-    # The drive_letter? method retrieves the drive letter from the current path
-    # in a Windows environment. This method returns the drive letter as a string
-    # only if File::ALT_SEPARATOR is present and the path is absolute.
-    # It returns nil if the path is not absolute, the environment is not Windows,
-    # or there is no drive letter present.
-    def drive_letter?
-      if File::ALT_SEPARATOR && absolute?
-        to_s[0, 2]
-      else
-        nil
-      end
-    end
-
-    # Compute the relative path from the 'src' path (directory) to 'tgt'
-    # (directory or file). Return the absolute path to 'tgt' if it can't
-    # be reached from 'src'.
-    def relative_path_from(other)
-      other = Pathname.new(other) unless other.is_a?(Pathname)
-
-      if absolute? != other.absolute?
-        raise ArgumentError, "both paths must be either absolute or relative"
-      end
-      a = to_s.split(Pathname::SEPARATOR_PAT)
-      b = other.to_s.split(Pathname::SEPARATOR_PAT)
-      while a.first && b.first && pathequal(a.first, b.first)
-        a.shift
-        b.shift
-      end
-      b.size.times { a.unshift ".." }
-      Pathname.new(File.join(*a))
-    end
-
     # Determines if 'src' is contained in 'tgt' (i.e. it is a subpath of
     # 'tgt'). Both must be absolute paths and not contain '..'
     def subpath?(base_directory)
@@ -105,18 +52,6 @@ module Ocran
       src_normalized =~ /^#{Regexp.escape tgt_normalized}#{Pathname::SEPARATOR_PAT}/i
     end
 
-    # Join two pathnames together. Returns the right-hand side if it
-    # is an absolute path. Otherwise, returns the full path of the
-    # left + right.
-    def /(other)
-      other = Pathname === other ? other : Pathname.new(other)
-      if other.absolute?
-        other
-      else
-        Pathname.new(File.join(@path, other.to_s))
-      end
-    end
-
     # Appends the given suffix to the filename, preserving the file extension.
     # If the filename has an extension, the suffix is inserted before the extension.
     # If the filename does not have an extension, the suffix is appended to the end.
@@ -130,19 +65,7 @@ module Ocran
     #   pathname.append_to_filename("_bar") # => #<Pathname:path.to/foo_bar>
     #
     def append_to_filename(suffix)
-      sub(/(.*?#{SEPARATOR_PAT})?(\.?[^.]+)?(\..*)?\z/, "\\1\\2#{suffix}\\3")
-    end
-
-    def sub(*a, &b)
-      Pathname.new(@path.sub(*a, &b))
-    end
-
-    def sub_ext(new_ext)
-      sub(/(\.[^.]*?)?$/, new_ext)
-    end
-
-    def extname
-      File.extname(@path)
+      sub(/(.*?#{Pathname::SEPARATOR_PAT})?(\.?[^.]+)?(\..*)?\z/, "\\1\\2#{suffix}\\3")
     end
 
     # Checks if the file's extension matches the expected extension.
@@ -151,52 +74,6 @@ module Ocran
     def extname?(expected_ext)
       extname.casecmp(expected_ext) == 0
     end
-
-    def find(ignore_error: true)
-      require "find"
-      if block_given?
-        Find.find(@path, ignore_error: ignore_error) { |path| yield Pathname.new(path) }
-      else
-        Find.find(@path, ignore_error: ignore_error).map{ |path| Pathname.new(path) }.to_enum
-      end
-    end
-
-    def exist?; File.exist?(@path); end
-    def file?; File.file?(@path); end
-    def directory?; File.directory?(@path); end
-    def absolute?; @path =~ ABSOLUTE_PAT; end
-    def dirname; Pathname.new(File.dirname(@path)); end
-    def basename; Pathname.new(File.basename(@path)); end
-
-    def expand_path(dir = ".")
-      Pathname.new(File.expand_path(@path, dir))
-    end
-
-    def size; File.size(@path); end
-
-    def binread(*args)
-      File.binread(@path, *args)
-    end
-
-    def parent
-      Pathname.new(File.basename(File.dirname(@path)))
-    end
-
-    def to_path; @path; end
-
-    def to_s; @path; end
-  end
-
-  # Type conversion for the Pathname class. Works with Pathname and String only.
-  def self.Pathname(obj)
-    case obj
-    when Pathname
-      obj
-    when String
-      Pathname.new(obj)
-    else
-      raise ArgumentError, obj
-    end
   end
 
   IGNORE_MODULE_NAMES = /\A(enumerator.so|rational.so|complex.so|fiber.so|thread.rb|ruby2_keywords.rb)\z/
@@ -720,6 +597,11 @@ EOF
   end
 
   def Ocran.build_exe
+    # The `RefinePathname` module is prepended to the `Pathname` class. This is done
+    # after the user script has finished executing and only the Ocran code is running,
+    # to avoid affecting the script environment.
+    ::Pathname.prepend(RefinePathname)
+
     all_load_paths = $LOAD_PATH.map { |loadpath| Pathname(loadpath).expand_path }
     @added_load_paths = ($LOAD_PATH - @load_path_before).map { |loadpath| Pathname(loadpath).expand_path }
     working_directory = Pathname.pwd