Improve `rake stats` for JavaScript and CoffeeScript.

Ignore block comments and calculates number of functions.

4 files changed, 394 insertions, 46 deletions

diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index 2d197e21ea..fc362837d6 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -1,5 +1,10 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Improve `rake stats` for JavaScript and CoffeeScript: ignore block comments
+    and calculates number of functions.
+
+    *Hendy Tanata*
+
 *   Ability to use a custom builder by passing `--builder` (or `-b`) has been removed. Consider
     using application template instead. See this guide for more detail:
     http://guides.rubyonrails.org/rails_application_templates.html
diff --git a/railties/lib/rails/code_statistics.rb b/railties/lib/rails/code_statistics.rb
index 039360fcf6..0ae6d2a455 100644
--- a/railties/lib/rails/code_statistics.rb
+++ b/railties/lib/rails/code_statistics.rb
@@ -1,3 +1,5 @@
+require 'rails/code_statistics_calculator'
+
 class CodeStatistics #:nodoc:
 
   TEST_TYPES = ['Controller tests',
@@ -33,64 +35,38 @@ class CodeStatistics #:nodoc:
     end
 
     def calculate_directory_statistics(directory, pattern = /.*\.(rb|js|coffee)$/)
-      stats = { "lines" => 0, "codelines" => 0, "classes" => 0, "methods" => 0 }
+      stats = CodeStatisticsCalculator.new
 
       Dir.foreach(directory) do |file_name|
-        if File.directory?(directory + "/" + file_name) and (/^\./ !~ file_name)
-          newstats = calculate_directory_statistics(directory + "/" + file_name, pattern)
-          stats.each { |k, v| stats[k] += newstats[k] }
+        path = "#{directory}/#{file_name}"
+
+        if File.directory?(path) && (/^\./ !~ file_name)
+          stats.add(calculate_directory_statistics(path, pattern))
         end
 
         next unless file_name =~ pattern
 
-        comment_started = false
-        
-        case file_name
-        when /.*\.js$/
-          comment_pattern = /^\s*\/\//
-        else
-          comment_pattern = /^\s*#/
-        end
-
-        File.open(directory + "/" + file_name) do |f|
-          while line = f.gets
-            stats["lines"]     += 1
-            if(comment_started)
-              if line =~ /^=end/
-                comment_started = false
-              end
-              next
-            else
-              if line =~ /^=begin/
-                comment_started = true
-                next
-              end
-            end
-            stats["classes"]   += 1 if line =~ /^\s*class\s+[_A-Z]/
-            stats["methods"]   += 1 if line =~ /^\s*def\s+[_a-z]/
-            stats["codelines"] += 1 unless line =~ /^\s*$/ || line =~ comment_pattern
-          end
-        end
+        stats.add_by_file_path(path)
       end
 
       stats
     end
 
     def calculate_total
-      total = { "lines" => 0, "codelines" => 0, "classes" => 0, "methods" => 0 }
-      @statistics.each_value { |pair| pair.each { |k, v| total[k] += v } }
-      total
+      @statistics.each_with_object(CodeStatisticsCalculator.new) do |pair, total|
+        total.add(pair.last)
+      end
     end
 
     def calculate_code
       code_loc = 0
-      @statistics.each { |k, v| code_loc += v['codelines'] unless TEST_TYPES.include? k }
+      @statistics.each { |k, v| code_loc += v.code_lines unless TEST_TYPES.include? k }
       code_loc
     end
 
     def calculate_tests
       test_loc = 0
-      @statistics.each { |k, v| test_loc += v['codelines'] if TEST_TYPES.include? k }
+      @statistics.each { |k, v| test_loc += v.code_lines if TEST_TYPES.include? k }
       test_loc
     end
 
@@ -105,15 +81,15 @@ class CodeStatistics #:nodoc:
     end
 
     def print_line(name, statistics)
-      m_over_c   = (statistics["methods"] / statistics["classes"])   rescue m_over_c = 0
-      loc_over_m = (statistics["codelines"] / statistics["methods"]) - 2 rescue loc_over_m = 0
-
-      puts "| #{name.ljust(20)} " +
-           "| #{statistics["lines"].to_s.rjust(5)} " +
-           "| #{statistics["codelines"].to_s.rjust(5)} " +
-           "| #{statistics["classes"].to_s.rjust(7)} " +
-           "| #{statistics["methods"].to_s.rjust(7)} " +
-           "| #{m_over_c.to_s.rjust(3)} " +
+      m_over_c   = (statistics.methods / statistics.classes) rescue m_over_c = 0
+      loc_over_m = (statistics.code_lines / statistics.methods) - 2 rescue loc_over_m = 0
+
+      puts "| #{name.ljust(20)} " \
+           "| #{statistics.lines.to_s.rjust(5)} " \
+           "| #{statistics.code_lines.to_s.rjust(5)} " \
+           "| #{statistics.classes.to_s.rjust(7)} " \
+           "| #{statistics.methods.to_s.rjust(7)} " \
+           "| #{m_over_c.to_s.rjust(3)} " \
            "| #{loc_over_m.to_s.rjust(5)} |"
     end
 
diff --git a/railties/lib/rails/code_statistics_calculator.rb b/railties/lib/rails/code_statistics_calculator.rb
new file mode 100644
index 0000000000..60e4aef9b7
--- /dev/null
+++ b/railties/lib/rails/code_statistics_calculator.rb
@@ -0,0 +1,79 @@
+class CodeStatisticsCalculator #:nodoc:
+  attr_reader :lines, :code_lines, :classes, :methods
+
+  PATTERNS = {
+    rb: {
+      line_comment: /^\s*#/,
+      begin_block_comment: /^=begin/,
+      end_block_comment: /^=end/,
+      class: /^\s*class\s+[_A-Z]/,
+      method: /^\s*def\s+[_a-z]/,
+    },
+    js: {
+      line_comment: %r{^\s*//},
+      begin_block_comment: %r{^\s*/\*},
+      end_block_comment: %r{\*/},
+      method: /function(\s+[_a-zA-Z][\da-zA-Z]*)?\s*\(/,
+    },
+    coffee: {
+      line_comment: /^\s*#/,
+      begin_block_comment: /^\s*###/,
+      end_block_comment: /^\s*###/,
+      class: /^\s*class\s+[_A-Z]/,
+      method: /[-=]>/,
+    }
+  }
+
+  def initialize(lines = 0, code_lines = 0, classes = 0, methods = 0)
+    @lines = lines
+    @code_lines = code_lines
+    @classes = classes
+    @methods = methods
+  end
+
+  def add(code_statistics_calculator)
+    @lines += code_statistics_calculator.lines
+    @code_lines += code_statistics_calculator.code_lines
+    @classes += code_statistics_calculator.classes
+    @methods += code_statistics_calculator.methods
+  end
+
+  def add_by_file_path(file_path)
+    File.open(file_path) do |f|
+      self.add_by_io(f, file_type(file_path))
+    end
+  end
+
+  def add_by_io(io, file_type)
+    patterns = PATTERNS[file_type] || {}
+
+    comment_started = false
+
+    while line = io.gets
+      @lines += 1
+
+      if comment_started
+        if patterns[:end_block_comment] && line =~ patterns[:end_block_comment]
+          comment_started = false
+        end
+        next
+      else
+        if patterns[:begin_block_comment] && line =~ patterns[:begin_block_comment]
+          comment_started = true
+          next
+        end
+      end
+
+      @classes   += 1 if patterns[:class] && line =~ patterns[:class]
+      @methods   += 1 if patterns[:method] && line =~ patterns[:method]
+      if line !~ /^\s*$/ && (patterns[:line_comment].nil? || line !~ patterns[:line_comment])
+        @code_lines += 1
+      end
+    end
+  end
+
+  private
+    def file_type(file_path)
+      File.extname(file_path).sub(/\A\./, '').downcase.to_sym
+    end
+end
diff --git a/railties/test/code_statistics_calculator_test.rb b/railties/test/code_statistics_calculator_test.rb
new file mode 100644
index 0000000000..b3eabf5024
--- /dev/null
+++ b/railties/test/code_statistics_calculator_test.rb
@@ -0,0 +1,288 @@
+require 'abstract_unit'
+require 'rails/code_statistics_calculator'
+
+class CodeStatisticsCalculatorTest < ActiveSupport::TestCase
+  def setup
+    @code_statistics_calculator = CodeStatisticsCalculator.new
+  end
+
+  test 'add statistics to another using #add' do
+    code_statistics_calculator_1 = CodeStatisticsCalculator.new(1, 2, 3, 4)
+    @code_statistics_calculator.add(code_statistics_calculator_1)
+
+    assert_equal 1, @code_statistics_calculator.lines
+    assert_equal 2, @code_statistics_calculator.code_lines
+    assert_equal 3, @code_statistics_calculator.classes
+    assert_equal 4, @code_statistics_calculator.methods
+
+    code_statistics_calculator_2 =  CodeStatisticsCalculator.new(2, 3, 4, 5)
+    @code_statistics_calculator.add(code_statistics_calculator_2)
+
+    assert_equal 3, @code_statistics_calculator.lines
+    assert_equal 5, @code_statistics_calculator.code_lines
+    assert_equal 7, @code_statistics_calculator.classes
+    assert_equal 9, @code_statistics_calculator.methods
+  end
+
+  test 'accumulate statistics using #add_by_io' do
+    code_statistics_calculator_1 = CodeStatisticsCalculator.new(1, 2, 3, 4)
+    @code_statistics_calculator.add(code_statistics_calculator_1)
+
+    code = <<-'CODE'
+      def foo
+        puts 'foo'
+      end
+
+      def bar; end
+      class A; end
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :rb)
+
+    assert_equal 7, @code_statistics_calculator.lines
+    assert_equal 7, @code_statistics_calculator.code_lines
+    assert_equal 4, @code_statistics_calculator.classes
+    assert_equal 6, @code_statistics_calculator.methods
+  end
+
+  test 'calculate statistics using #add_by_file_path' do
+    tmp_path = File.expand_path(File.join(File.dirname(__FILE__), 'fixtures', 'tmp'))
+    FileUtils.mkdir_p(tmp_path)
+
+    code = <<-'CODE'
+      def foo
+        puts 'foo'
+        # bar
+      end
+    CODE
+
+    file_path = "#{tmp_path}/stats.rb"
+    File.open(file_path, 'w') { |f| f.write(code) }
+
+    @code_statistics_calculator.add_by_file_path(file_path)
+
+    assert_equal 4, @code_statistics_calculator.lines
+    assert_equal 3, @code_statistics_calculator.code_lines
+    assert_equal 0, @code_statistics_calculator.classes
+    assert_equal 1, @code_statistics_calculator.methods
+
+    FileUtils.rm_rf(tmp_path)
+  end
+
+  test 'calculate number of Ruby methods' do
+    code = <<-'CODE'
+      def foo
+        puts 'foo'
+      end
+
+      def bar; end
+
+      class Foo
+        def bar(abc)
+        end
+      end
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :rb)
+
+    assert_equal 3, @code_statistics_calculator.methods
+  end
+
+  test 'calculate Ruby LOCs' do
+    code = <<-'CODE'
+      def foo
+        puts 'foo'
+      end
+
+      # def bar; end
+
+      class A < B
+      end
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :rb)
+
+    assert_equal 8, @code_statistics_calculator.lines
+    assert_equal 5, @code_statistics_calculator.code_lines
+  end
+
+  test 'calculate number of Ruby classes' do
+    code = <<-'CODE'
+      class Foo < Bar
+        def foo
+          puts 'foo'
+        end
+      end
+
+      class Z; end
+
+      # class A
+      # end
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :rb)
+
+    assert_equal 2, @code_statistics_calculator.classes
+  end
+
+  test 'skip Ruby comments' do
+    code = <<-'CODE'
+=begin
+      class Foo
+        def foo
+          puts 'foo'
+        end
+      end
+=end
+
+      # class A
+      # end
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :rb)
+
+    assert_equal 10, @code_statistics_calculator.lines
+    assert_equal 0, @code_statistics_calculator.code_lines
+    assert_equal 0, @code_statistics_calculator.classes
+    assert_equal 0, @code_statistics_calculator.methods
+  end
+
+  test 'calculate number of JS methods' do
+    code = <<-'CODE'
+      function foo(x, y, z) {
+        doX();
+      }
+
+      $(function () {
+        bar();
+      })
+
+      var baz = function ( x ) {
+      }
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :js)
+
+    assert_equal 3, @code_statistics_calculator.methods
+  end
+
+  test 'calculate JS LOCs' do
+    code = <<-'CODE'
+      function foo()
+        alert('foo');
+      end
+
+      // var b = 2;
+
+      var a = 1;
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :js)
+
+    assert_equal 7, @code_statistics_calculator.lines
+    assert_equal 4, @code_statistics_calculator.code_lines
+  end
+
+  test 'skip JS comments' do
+    code = <<-'CODE'
+      /*
+       * var f = function () {
+       1 / 2;
+      }
+      */
+
+      // call();
+      //
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :js)
+
+    assert_equal 8, @code_statistics_calculator.lines
+    assert_equal 0, @code_statistics_calculator.code_lines
+    assert_equal 0, @code_statistics_calculator.classes
+    assert_equal 0, @code_statistics_calculator.methods
+  end
+
+  test 'calculate number of CoffeeScript methods' do
+    code = <<-'CODE'
+      square = (x) -> x * x
+
+      math =
+        cube: (x) -> x * square x
+
+      fill = (container, liquid = "coffee") ->
+        "Filling the #{container} with #{liquid}..."
+
+      $('.shopping_cart').bind 'click', (event) =>
+        @customer.purchase @cart
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :coffee)
+
+    assert_equal 4, @code_statistics_calculator.methods
+  end
+
+  test 'calculate CoffeeScript LOCs' do
+    code = <<-'CODE'
+      # Assignment:
+      number   = 42
+      opposite = true
+
+      ###
+      CoffeeScript Compiler v1.4.0
+      Released under the MIT License
+      ###
+
+      # Conditions:
+      number = -42 if opposite
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :coffee)
+
+    assert_equal 11, @code_statistics_calculator.lines
+    assert_equal 3, @code_statistics_calculator.code_lines
+  end
+
+  test 'calculate number of CoffeeScript classes' do
+    code = <<-'CODE'
+      class Animal
+        constructor: (@name) ->
+
+        move: (meters) ->
+          alert @name + " moved #{meters}m."
+
+      class Snake extends Animal
+        move: ->
+          alert "Slithering..."
+          super 5
+
+      # class Horse
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :coffee)
+
+    assert_equal 2, @code_statistics_calculator.classes
+  end
+
+  test 'skip CoffeeScript comments' do
+    code = <<-'CODE'
+###
+class Animal
+  constructor: (@name) ->
+
+  move: (meters) ->
+    alert @name + " moved #{meters}m."
+  ###
+
+  # class Horse
+  alert 'hello'
+    CODE
+
+    @code_statistics_calculator.add_by_io(StringIO.new(code), :coffee)
+
+    assert_equal 10, @code_statistics_calculator.lines
+    assert_equal 1, @code_statistics_calculator.code_lines
+    assert_equal 0, @code_statistics_calculator.classes
+    assert_equal 0, @code_statistics_calculator.methods
+  end
+end