オブジェクト指向版lsコマンドの実装

07.ls_object/directory_entry.rb

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+# frozen_string_literal: true
+
+require_relative 'file_entry'
+
+class DirectoryEntry
+  attr_accessor :path, :file_entries
+
+  def initialize(path, options)
+    @path = path
+    @options = options
+    @file_entries = collect_file_entries
+  end
+
+  def find_max_sizes
+    %i[nlink user group size time].to_h do |key|
+      [key, @file_entries.map { |entry| entry.send(key).size }.max]
+    end
+  end
+
+  def total
+    @file_entries.map(&:blocks).sum
+  end
+
+  private
+
+  def collect_file_entries
+    pattern = @path.join('*')
+    params = @options[:dot_match] ? [pattern, File::FNM_DOTMATCH] : [pattern]
+    Dir.glob(*params)
+       .map { |file| FileEntry.new(file) }
+       .sort_by(&:name)
+       .then { |file_entries| @options[:reverse] ? file_entries.reverse : file_entries }
+  end
+end

07.ls_object/file_entry.rb

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+# frozen_string_literal: true
+
+require 'etc'
+
+FILE_TYPES = {
+  'file' => '-',
+  'directory' => 'd',
+  'characterSpecial' => 'c',
+  'blockSpecial' => 'b',
+  'link' => 'l',
+  'socket' => 's',
+  'fifo' => 'p'
+}.freeze
+BLOCK_SIZE = 1024
+
+class FileEntry
+  attr_reader :path
+
+  def initialize(path)
+    @path = path
+    @stat = File.lstat(@path)
+  end
+
+  def mode
+    file_type = FILE_TYPES[@stat.ftype]
+    file_permissions = @stat.mode.to_s(8).rjust(6, '0')[3..5].chars.map do |c|
+      rwx = %w[- x w . r]
+      rwx[c.to_i & 0b100] + rwx[c.to_i & 0b010] + rwx[c.to_i & 0b001]
+    end.join
+
+    file_type + file_permissions
+  end
+
+  def nlink
+    @stat.nlink.to_s
+  end
+
+  def user
+    Etc.getpwuid(@stat.uid).name
+  end
+
+  def group
+    Etc.getgrgid(@stat.gid).name
+  end
+
+  def size
+    @stat.size.to_s
+  end
+
+  def time
+    @stat.mtime.strftime('%-m月 %e %H:%M')
+  end
+
+  def name
+    File.basename(@path)
+  end
+
+  def blocks
+    # File::statのブロックサイズの単位は512bytesであるから変換する
+    @stat.blocks * (512 / BLOCK_SIZE.to_f)
+  end
+end

07.ls_object/long_formatter.rb

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+# frozen_string_literal: true
+
+class LongFormatter
+  def run(entries)
+    header = ["合計 #{entries.total.to_i}"]
+    max_sizes = entries.find_max_sizes
+    body = entries.file_entries.map do |file|
+      "#{file.mode} "\
+      "#{file.nlink.rjust(max_sizes[:nlink])} " \
+      "#{file.user.ljust(max_sizes[:user])} " \
+      "#{file.group.ljust(max_sizes[:group])} " \
+      "#{file.size.rjust(max_sizes[:size])}  " \
+      "#{file.time.rjust(max_sizes[:time])} " \
+      "#{file.name}" \
+    end.join("\n")
+    [header, body].join("\n")
+  end
+end

07.ls_object/ls_command.rb

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+# frozen_string_literal: true
+
+require 'io/console'
+require_relative 'directory_entry'
+require_relative 'short_formatter'
+require_relative 'long_formatter'
+
+class LsCommand
+  def initialize(paths, options)
+    @paths = paths
+    @options = options
+    @formatter = @options[:long_format] ? LongFormatter.new : ShortFormatter.new
+    @directories = @paths.map { |path| DirectoryEntry.new(path, @options) }
+                         .sort_by(&:path)
+                         .then { |directories| @options[:reverse] ? directories.reverse : directories }
+  end
+
+  def run
+    output = @directories.map do |dir_entry|
+      header = "#{dir_entry.path}:" if @directories.count > 1
+      body = @formatter.run(dir_entry)
+      [header, body].compact.join("\n")
+    end.join("\n\n").rstrip
+
+    puts output
+  end
+end

07.ls_object/main.rb

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+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require 'optparse'
+require 'pathname'
+require_relative 'ls_command'
+
+opt = OptionParser.new
+options = { long_format: false, reverse: false, dot_match: false }
+opt.on('-l') { |v| options[:long_format] = v }
+opt.on('-r') { |v| options[:reverse] = v }
+opt.on('-a') { |v| options[:dot_match] = v }
+opt.parse!(ARGV)
+paths = ARGV.empty? ? [Pathname('.')] : ARGV.map { |path| Pathname(path) }
+command = LsCommand.new(paths, options)
+command.run

07.ls_object/short_formatter.rb

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+# frozen_string_literal: true
+
+require 'io/console'
+class ShortFormatter
+  def initialize
+    @window_width = IO.console.winsize[1]
+  end
+
+  def run(entries)
+    return if entries.file_entries.count.zero?
+
+    max_file_name_count = entries.file_entries.map { |f| f.name.size }.max
+    col_count = @window_width / (max_file_name_count + 1)
+    row_count = col_count.zero? ? entries.count : (entries.file_entries.count.to_f / col_count).ceil
+    transposed_file_entries = safe_transpose(entries.file_entries.each_slice(row_count).to_a)
+    format_table(transposed_file_entries, max_file_name_count)
+  end
+
+  private
+
+  def safe_transpose(nested_file_entries)
+    nested_file_entries[0].zip(*nested_file_entries[1..]).map(&:compact)
+  end
+
+  def format_table(file_entries, max_file_name_size)
+    file_entries.map do |row_file_entries|
+      render_short_format_row(row_file_entries, max_file_name_size)
+    end.join("\n")
+  end
+
+  def render_short_format_row(row_file_entries, max_file_name_size)
+    row_file_entries.map do |file_entry|
+      file_entry.name.ljust(max_file_name_size + 1)
+    end.join.rstrip
+  end
+end

test/directory_entry_test.rb

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+# frozen_string_literal: true
+
+require 'minitest/autorun'
+require 'pathname'
+require 'io/console'
+require_relative '../07.ls_object/directory_entry'
+
+class DirEntryTest < Minitest::Test
+  def test_dir_total
+    expected_total = 4
+    options = { dot_match: false }
+    directory = DirectoryEntry.new(Pathname('test/files/'), options)
+    assert_equal expected_total, directory.total
+  end
+end

test/file_entry_test.rb

@@ -0,0 +1,79 @@
+# frozen_string_literal: true
+
+require 'minitest/autorun'
+require 'pathname'
+require_relative '../07.ls_object/file_entry'
+
+class FileEntryTest < Minitest::Test
+  def test_monde_file
+    expected_mode = <<~TEXT.chomp
+      -rw-r--r--
+    TEXT
+    file = FileEntry.new(Pathname('./test/files/test.txt'))
+    assert_equal expected_mode, file.mode
+  end
+
+  def test_monde_directory
+    expected_mode = <<~TEXT.chomp
+      drwxr-xr-x
+    TEXT
+    file = FileEntry.new(Pathname('./test/files'))
+    assert_equal expected_mode, file.mode
+  end
+
+  def test_monde_link
+    expected_mode = <<~TEXT.chomp
+      lrwxrwxrwx
+    TEXT
+    file = FileEntry.new(Pathname('./test/files/text_link'))
+    assert_equal expected_mode, file.mode
+  end
+
+  def test_nlink
+    expected_mode = <<~TEXT.chomp
+      1
+    TEXT
+    file = FileEntry.new(Pathname('./test/files/test.txt'))
+    assert_equal expected_mode, file.nlink
+  end
+
+  def test_user
+    expected_mode = <<~TEXT.chomp
+      migi
+    TEXT
+    file = FileEntry.new(Pathname('./test/files/test.txt'))
+    assert_equal expected_mode, file.user
+  end
+
+  def test_group
+    expected_mode = <<~TEXT.chomp
+      migi
+    TEXT
+    file = FileEntry.new(Pathname('./test/files/test.txt'))
+    assert_equal expected_mode, file.group
+  end
+
+  def test_size
+    expected_mode = <<~TEXT.chomp
+      5
+    TEXT
+    file = FileEntry.new(Pathname('./test/files/test.txt'))
+    assert_equal expected_mode, file.size
+  end
+
+  def test_time
+    expected_mode = <<~TEXT.chomp
+      9月 11 00:11
+    TEXT
+    file = FileEntry.new(Pathname('./test/files/test.txt'))
+    assert_equal expected_mode, file.time
+  end
+
+  def test_mode
+    expected_mode = <<~TEXT.chomp
+      test.txt
+    TEXT
+    file = FileEntry.new(Pathname('./test/files/test.txt'))
+    assert_equal expected_mode, file.name
+  end
+end

test/files/test.txt

@@ -0,0 +1 @@
+test

test/files/text_link

@@ -0,0 +1 @@
+test.txt

test/long_formatter_test.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+require 'minitest/autorun'
+require 'pathname'
+require 'io/console'
+require_relative '../07.ls_object/long_formatter'
+require_relative '../07.ls_object/directory_entry'
+
+class DirEntryTest < Minitest::Test
+  def test_ls_long_if_target_is_file
+    expected = <<~TEXT.chomp
+      合計 4
+      -rw-r--r-- 1 migi migi 5  9月 11 00:11 test.txt
+      lrwxrwxrwx 1 migi migi 8  9月 11 00:21 text_link
+    TEXT
+    options = { dot_match: false }
+    directory = DirectoryEntry.new(Pathname('./test/files'), options)
+    formatter = LongFormatter.new
+    assert_equal expected, formatter.run(directory)
+  end
+end

test/ls_command_test.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+require 'minitest/autorun'
+require 'pathname'
+require_relative '../07.ls_object/ls_command'
+
+class LsCommandTest < Minitest::Test
+  def test_run_with_multiple_directories
+    LsCommand.class_eval do
+      attr_accessor :formatter
+    end
+
+    ShortFormatter.class_eval do
+      attr_accessor :window_width
+    end
+
+    expected = <<~TEXT
+      ./test/ls_short_test_files/:
+      123456789  defghijk   z          zzzzz
+      56789      directory  zz         zzzzzz
+      9999       ls.rb      zzz
+      abc        qwertfdsdf zzzz
+
+      ./test/ls_short_test_files/:
+      123456789  defghijk   z          zzzzz
+      56789      directory  zz         zzzzzz
+      9999       ls.rb      zzz
+      abc        qwertfdsdf zzzz
+    TEXT
+    path1 = Pathname('./test/ls_short_test_files/')
+    path2 = Pathname('./test/ls_short_test_files/')
+    paths = [path1, path2]
+    options = { long_format: false, dot_match: false }
+    command = LsCommand.new(paths, options)
+    command.instance_variable_set(:@format, ShortFormatter.new)
+    command.formatter.window_width = 50
+    assert_output(expected) { command.run }
+  end
+
+  def test_run_long
+    expected = <<~TEXT
+      合計 4
+      -rw-r--r-- 1 migi migi 5  9月 11 00:11 test.txt
+      lrwxrwxrwx 1 migi migi 8  9月 11 00:21 text_link
+    TEXT
+    options = { long_format: true, dot_match: false }
+
+    path = Pathname('./test/files')
+    paths = [path]
+    command = LsCommand.new(paths, options)
+    assert_output(expected) { command.run }
+  end
+end