Add unit and cucumber tests

features/incremental_rebuild.feature

@@ -0,0 +1,60 @@
+Feature: Incremental rebuild
+  As an impatient hacker who likes to blog
+  I want to be able to make a static site
+  Without waiting too long for it to build
+
+  Scenario: Produce correct output site
+    Given I have a _layouts directory
+    And I have a _posts directory
+    And I have the following posts:
+      | title    | date       | layout  | content                               |
+      | Wargames | 2009-03-27 | default | The only winning move is not to play. |
+    And I have a default layout that contains "Post Layout: {{ content }}"
+    When I run jekyll build
+    Then the _site directory should exist
+    And I should see "Post Layout: <p>The only winning move is not to play.</p>" in "_site/2009/03/27/wargames.html"
+    When I run jekyll build
+    Then the _site directory should exist
+    And I should see "Post Layout: <p>The only winning move is not to play.</p>" in "_site/2009/03/27/wargames.html"
+
+  Scenario: Generate a metadata file
+    Given I have an "index.html" file that contains "Basic Site"
+    When I run jekyll build
+    Then the ".jekyll-metadata" file should exist
+
+  Scenario: Rebuild when content is changed
+    Given I have an "index.html" file that contains "Basic Site"
+    When I run jekyll build
+    Then the _site directory should exist
+    And I should see "Basic Site" in "_site/index.html"
+    When I wait 1 second
+    Then I have an "index.html" file that contains "Bacon Site"
+    When I run jekyll build
+    Then the _site directory should exist
+    And I should see "Bacon Site" in "_site/index.html"
+
+  Scenario: Rebuild when layout is changed
+    Given I have a _layouts directory
+    And I have an "index.html" page with layout "default" that contains "Basic Site with Layout"
+    And I have a default layout that contains "Page Layout: {{ content }}"
+    When I run jekyll build
+    Then the _site directory should exist
+    And I should see "Page Layout: Basic Site with Layout" in "_site/index.html"
+    When I wait 1 second
+    Then I have a default layout that contains "Page Layout Changed: {{ content }}"
+    When I run jekyll build --full-rebuild
+    Then the _site directory should exist
+    And I should see "Page Layout Changed: Basic Site with Layout" in "_site/index.html"
+
+  Scenario: Rebuild when an include is changed
+    Given I have a _includes directory
+    And I have an "index.html" page that contains "Basic Site with include tag: {% include about.textile %}"
+    And I have an "_includes/about.textile" file that contains "Generated by Jekyll"
+    When I run jekyll build
+    Then the _site directory should exist
+    And I should see "Basic Site with include tag: Generated by Jekyll" in "_site/index.html"
+    When I wait 1 second
+    Then I have an "_includes/about.textile" file that contains "Regenerated by Jekyll"
+    When I run jekyll build
+    Then the _site directory should exist
+    And I should see "Basic Site with include tag: Regenerated by Jekyll" in "_site/index.html"

features/step_definitions/jekyll_steps.rb

@@ -133,6 +133,10 @@ Given /^I have fixture collections$/ do
   FileUtils.cp_r File.join(JEKYLL_SOURCE_DIR, "test", "source", "_methods"), source_dir
 end
 
+Given /^I wait (\d+) second(s?)$/ do |time, plural|
+  sleep(time.to_f)
+end
+
 ##################
 #
 # Changing stuff

lib/jekyll/metadata.rb

@@ -36,8 +36,8 @@ module Jekyll
     #
     # Returns nothing
     def clear
-      metadata = {}
-      cache = {}
+      @metadata = {}
+      @cache = {}
     end
 
     # Checks if a path should be regenerated

test/test_metadata.rb

@@ -0,0 +1,38 @@
+require 'helper'
+
+class TestMetadata < Test::Unit::TestCase
+  context "The site metadata" do
+    setup do
+      FileUtils.rm_rf(source_dir(".jekyll-metadata"))
+
+      @site = Site.new(Jekyll.configuration({
+        "source" => source_dir,
+        "destination" => dest_dir
+      }))
+
+      @site.process
+      @path = @site.in_source_dir(@site.pages.first.path)
+      @metadata = @site.metadata
+    end
+
+    should "store modification times" do
+      assert_equal @metadata.metadata[@path]["mtime"], File.mtime(@path)
+    end
+
+    should "cache processed entries" do
+      assert @metadata.cache[@path]
+    end
+
+    should "write to the metadata file" do
+      @metadata.clear
+      @metadata.add(@path)
+      @metadata.write
+      assert File.file?(source_dir(".jekyll-metadata"))
+    end
+
+    should "read from the metadata file" do
+      @metadata = Metadata.new(@site)
+      assert_equal @metadata.metadata[@path]["mtime"], File.mtime(@path)
+    end
+  end
+end