make non-data properties/methods accessible to Liquid

per https://github.com/jekyll/jekyll/pull/1849/files#r8490593

lib/jekyll/convertible.rb

@@ -177,7 +177,11 @@ module Jekyll
     #
     # Returns the String value or nil if the property isn't included.
     def [](property)
-      data[property]
+      if self.class::ATTRIBUTES_FOR_LIQUID.include?(property)
+        send(property)
+      else
+        data[property]
+      end
     end
   end
 end

lib/jekyll/page.rb

@@ -9,9 +9,11 @@ module Jekyll
 
     # Attributes for Liquid templates
     ATTRIBUTES_FOR_LIQUID = %w[
-      url
       content
+      dir
+      name
       path
+      url
     ]
 
     # Initialize a new Page.

lib/jekyll/post.rb

@@ -9,6 +9,7 @@ module Jekyll
     EXCERPT_ATTRIBUTES_FOR_LIQUID = %w[
       title
       url
+      dir
       date
       id
       categories

test/source/_posts/2013-12-20-properties.text

@@ -0,0 +1,11 @@
+---
+categories: foo bar baz
+foo: bar
+layout: default
+tags: ay bee cee
+title: Properties Post
+---
+
+All the properties.
+
+Plus an excerpt.

test/source/properties.html

@@ -0,0 +1,8 @@
+---
+foo: bar
+layout: default
+permalink: /properties/
+title: Properties Page
+---
+
+All the properties.

test/test_filters.rb

@@ -120,7 +120,7 @@ class TestFilters < Test::Unit::TestCase
           case g["name"]
           when "default"
             assert g["items"].is_a?(Array), "The list of grouped items for 'default' is not an Array."
-            assert_equal 3, g["items"].size
+            assert_equal 4, g["items"].size
           when "nil"
             assert g["items"].is_a?(Array), "The list of grouped items for 'nil' is not an Array."
             assert_equal 2, g["items"].size

test/test_generated_site.rb

@@ -14,7 +14,7 @@ class TestGeneratedSite < Test::Unit::TestCase
     end
 
     should "ensure post count is as expected" do
-      assert_equal 36, @site.posts.size
+      assert_equal 37, @site.posts.size
     end
 
     should "insert site.posts into the index" do

test/test_page.rb

@@ -47,6 +47,29 @@ class TestPage < Test::Unit::TestCase
         assert_equal "deal.with.dots", @page.basename
       end
 
+      should "make properties accessible through #[]" do
+        page = setup_page('properties.html')
+        attrs = {
+          content: "All the properties.\n",
+          dir: "/properties/",
+          excerpt: nil,
+          foo: 'bar',
+          layout: 'default',
+          name: "properties.html",
+          path: "properties.html",
+          permalink: '/properties/',
+          published: nil,
+          title: 'Properties Page',
+          url: "/properties/"
+        }
+
+        attrs.each do |attr, val|
+          attr_str = attr.to_s
+          result = page[attr_str]
+          assert_equal val, result, "For <page[\"#{attr_str}\"]>:"
+        end
+      end
+
       context "with pretty url style" do
         setup do
           @site.permalink_style = :pretty

test/test_post.rb

@@ -25,6 +25,34 @@ class TestPost < Test::Unit::TestCase
       assert !Post.valid?("blah")
     end
 
+    should "make properties accessible through #[]" do
+      post = setup_post('2013-12-20-properties.text')
+
+      attrs = {
+        categories: %w(foo bar baz),
+        content: "All the properties.\n\nPlus an excerpt.\n",
+        date: Time.new(2013, 12, 20),
+        dir: "/foo/bar/baz/2013/12/20",
+        excerpt: "All the properties.\n\n",
+        foo: 'bar',
+        id: "/foo/bar/baz/2013/12/20/properties",
+        layout: 'default',
+        name: nil,
+        # path: "properties.html",
+        permalink: nil,
+        published: nil,
+        tags: %w(ay bee cee),
+        title: 'Properties Post',
+        url: "/foo/bar/baz/2013/12/20/properties.html"
+      }
+
+      attrs.each do |attr, val|
+        attr_str = attr.to_s
+        result = post[attr_str]
+        assert_equal val, result, "For <post[\"#{attr_str}\"]>:"
+      end
+    end
+
     context "processing posts" do
       setup do
         @post = Post.allocate

test/test_site.rb

@@ -176,7 +176,7 @@ class TestSite < Test::Unit::TestCase
 
       assert_equal posts.size - @num_invalid_posts, @site.posts.size
       assert_equal categories, @site.categories.keys.sort
-      assert_equal 4, @site.categories['foo'].size
+      assert_equal 5, @site.categories['foo'].size
     end
 
     context 'error handling' do