[Command Line] Specification of sass files to compile

The command line compiler now lets you target specific sass files for
compilation. When specified explicitly, the sass files are always
compiled even if they are older than the corresponding css file (--force
is implied).

Usage Examples:

From the project directory:
compass compile src/screen.sass src/ie.sass

From another directory:
compass compile my_project my_project/src/screen.sass my_project/src/ie.sass

features/command_line.feature

@@ -120,6 +120,26 @@ Feature: Command Line
     And a sass file sass/reset.sass is reported unchanged
     And a sass file sass/utilities.sass is reported unchanged
 
+  Scenario: compiling a specific file in a project
+    Given I am using the existing project in test/fixtures/stylesheets/compass
+    And I run: compass compile sass/utilities.sass
+    Then a sass file sass/layout.sass is not mentioned
+    And a sass file sass/print.sass is not mentioned
+    And a sass file sass/reset.sass is not mentioned
+    And a sass file sass/utilities.sass is reported compiled
+    And a css file tmp/utilities.css is reported created
+    And a css file tmp/utilities.css is created
+
+  Scenario: Re-compiling a specific file in a project with no changes
+    Given I am using the existing project in test/fixtures/stylesheets/compass
+    When I run: compass compile
+    And I run: compass compile sass/utilities.sass
+    Then a sass file sass/layout.sass is not mentioned
+    And a sass file sass/print.sass is not mentioned
+    And a sass file sass/reset.sass is not mentioned
+    And a sass file sass/utilities.sass is reported compiled
+    And a css file tmp/utilities.css is reported identical
+
   Scenario: Installing a pattern into a project
     Given I am using the existing project in test/fixtures/stylesheets/compass
     When I run: compass install blueprint/buttons
@@ -129,7 +149,6 @@ Feature: Command Line
     And an image file images/buttons/tick.png is created
     And a css file tmp/buttons.css is created
 
-  @now
   Scenario: Basic help
     When I run: compass help
     Then I should see the following "primary" commands:

features/step_definitions/command_line_steps.rb

@@ -135,6 +135,10 @@ Then /a \w+ file ([^ ]+) is reported overwritten/ do |filename|
   @last_result.should =~ /overwrite #{Regexp.escape(filename)}/
 end
 
+Then /a \w+ file ([^ ]+) is not mentioned/ do |filename|
+  @last_result.should_not =~ /#{Regexp.escape(filename)}/
+end
+
 Then /I am told how to link to ([^ ]+) for media "([^"]+)"/ do |stylesheet, media|
   @last_result.should =~ %r{<link href="#{stylesheet}" media="#{media}" rel="stylesheet" type="text/css" />}
 end

lib/compass/commands/update_project.rb

@@ -6,7 +6,7 @@ module Compass
     module CompileProjectOptionsParser
       def set_options(opts)
         opts.banner = %Q{
-          Usage: compass compile [path/to/project] [options]
+          Usage: compass compile [path/to/project] [path/to/project/src/file.sass ...] [options]
 
           Description:
           compile project at the path specified or the current director if not specified.
@@ -47,9 +47,22 @@ module Compass
           projectize(Compass.configuration.sass_dir),
           projectize(Compass.configuration.css_dir),
           Compass.sass_engine_options.merge(:quiet => options[:quiet],
-                                            :force => options[:force]).merge(additional_options))
+                                            :force => options[:force],
+                                            :sass_files => explicit_sass_files).merge(additional_options))
       end
 
+      def explicit_sass_files
+        return unless options[:sass_files]
+        options[:sass_files].map do |sass_file|
+          if absolute_path? sass_file
+            sass_file
+          else
+            File.join(Dir.pwd, sass_file)
+          end
+        end
+      end
+
+
       class << self
         def option_parser(arguments)
           parser = Compass::Exec::CommandOptionParser.new(arguments)
@@ -76,10 +89,12 @@ module Compass
         end
 
         def parse_arguments!(parser, arguments)
-          if arguments.size == 1
-            parser.options[:project_name] = arguments.shift
-          elsif arguments.size > 1
-            raise Compass::Error, "Too many arguments were specified."
+          if arguments.size > 0
+            parser.options[:project_name] = arguments.shift if File.directory?(arguments.first)
+            unless arguments.empty?
+              parser.options[:sass_files] = arguments.dup
+              parser.options[:force] = true
+            end
           end
         end
       end

lib/compass/compiler.rb

@@ -15,7 +15,7 @@ module Compass
 
     def sass_files(options = {})
       exclude_partials = options.fetch(:exclude_partials, true)
-      @sass_files || Dir.glob(separate("#{from}/**/#{'[^_]' if exclude_partials}*.sass"))
+      @sass_files = self.options[:sass_files] || Dir.glob(separate("#{from}/**/#{'[^_]' if exclude_partials}*.sass"))
     end
 
     def stylesheet_name(sass_file)