Added limit-posts option to site configuration.

* Added unit tests for limit-posts.
  * Added feature for limit-posts.
  * Added --limit_posts option to bin/jekyll options parser

bin/jekyll

@@ -78,6 +78,17 @@ opts = OptionParser.new do |opts|
     end
   end
 
+  opts.on("--limit_posts [MAX_POSTS]", "Limit the number of posts to publish") do |limit_posts|
+    begin
+      options['limit_posts'] = limit_posts.to_i
+      raise ArgumentError if options['limit_posts'] < 1
+    rescue
+      puts 'you must specify a number of posts by page bigger than 0'
+      exit 0
+    end
+  end
+
+
   opts.on("--url [URL]", "Set custom site.url") do |url|
     options['url'] = url
   end

features/create_sites.feature

@@ -89,6 +89,6 @@ Feature: Create sites
     And I have an "_includes/about.textile" file that contains "Generated by {% include jekyll.textile %}"
     And I have an "_includes/jekyll.textile" file that contains "Jekyll"
     And I have an "index.html" page that contains "Basic Site with include tag: {% include about.textile %}"
-    When I run jekyll
+    When I debug jekyll
     Then the _site directory should exist
-    And I should see "Basic Site with include tag: Generated by Jekyll" in "_site/index.html"
+    And I should see "Basic Site with include tag: Generated by Jekyll" in "_site/index.html"

features/site_configuration.feature

@@ -101,3 +101,19 @@ Feature: Site configuration
     And I should see "Page Layout: 2 on 2010-01-01" in "_site/index.html"
     And I should see "Post Layout: <p>content for entry1.</p>" in "_site/2007/12/31/entry1.html"
     And I should see "Post Layout: <p>content for entry2.</p>" in "_site/2020/01/31/entry2.html"
+
+  Scenario: Limit the number of posts generated by most recent date
+    Given I have a _posts directory
+    And I have a configuration file with:
+      | key         | value       |
+      | limit_posts | 2           |
+    And I have the following posts:
+      | title   | date      | content          |
+      | Apples  | 3/27/2009 | An article about apples |
+      | Oranges | 4/1/2009  | An article about oranges |
+      | Bananas | 4/5/2009  | An article about bananas |
+    When I run jekyll
+    Then the _site directory should exist
+    And the "_site/2009/04/05/bananas.html" file should exist
+    And the "_site/2009/04/01/oranges.html" file should exist
+    And the "_site/2009/03/27/apples.html" file should not exist

lib/jekyll/site.rb

@@ -3,7 +3,8 @@ module Jekyll
   class Site
     attr_accessor :config, :layouts, :posts, :pages, :static_files,
                   :categories, :exclude, :source, :dest, :lsi, :pygments,
-                  :permalink_style, :tags, :time, :future, :safe, :plugins
+                  :permalink_style, :tags, :time, :future, :safe, :plugins, :limit_posts
+
     attr_accessor :converters, :generators
 
     # Initialize the site
@@ -22,6 +23,7 @@ module Jekyll
       self.permalink_style = config['permalink'].to_sym
       self.exclude         = config['exclude'] || []
       self.future          = config['future']
+      self.limit_posts     = config['limit_posts'] || nil
 
       self.reset
       self.setup
@@ -39,6 +41,8 @@ module Jekyll
       self.static_files    = []
       self.categories      = Hash.new { |hash, key| hash[key] = [] }
       self.tags            = Hash.new { |hash, key| hash[key] = [] }
+
+      raise ArgumentError, "Limit posts must be nil or >= 1" if !self.limit_posts.nil? && self.limit_posts < 1
     end
 
     def setup
@@ -122,6 +126,9 @@ module Jekyll
       end
 
       self.posts.sort!
+
+      # limit the posts if :limit_posts option is set
+      self.posts = self.posts[-limit_posts, limit_posts] if limit_posts
     end
 
     def generate

test/test_generated_site.rb

@@ -41,4 +41,32 @@ class TestGeneratedSite < Test::Unit::TestCase
       assert File.exists?(dest_dir('/contacts.html'))
     end
   end
+
+  context "generating limited posts" do
+    setup do
+      clear_dest
+      stub(Jekyll).configuration do
+        Jekyll::DEFAULTS.merge({'source' => source_dir, 'destination' => dest_dir, 'limit_posts' => 5})
+      end
+
+      @site = Site.new(Jekyll.configuration)
+      @site.process
+      @index = File.read(dest_dir('index.html'))
+    end
+
+    should "generate only the specified number of posts" do
+      assert_equal 5, @site.posts.size
+    end
+
+    should "ensure limit posts is 1 or more" do
+      assert_raise ArgumentError do
+        clear_dest
+        stub(Jekyll).configuration do
+          Jekyll::DEFAULTS.merge({'source' => source_dir, 'destination' => dest_dir, 'limit_posts' => 0})
+        end
+
+        @site = Site.new(Jekyll.configuration)
+      end
+    end
+  end
 end