Added assert_select* for CSS selector-based testing (deprecates assert_tag) #5936 [assaf.arkin@gmail.com]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4929 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 1118 insertions, 0 deletions

diff --git a/actionpack/test/controller/assert_select_test.rb b/actionpack/test/controller/assert_select_test.rb
new file mode 100644
index 0000000000..2117c852c0
--- /dev/null
+++ b/actionpack/test/controller/assert_select_test.rb
@@ -0,0 +1,490 @@
+#--
+# Copyright (c) 2006 Assaf Arkin (http://labnotes.org)
+# Under MIT and/or CC By license.
+#++
+
+require File.dirname(__FILE__) + '/../abstract_unit'
+require File.dirname(__FILE__) + '/fake_controllers'
+require "action_mailer"
+
+class AssertSelectTest < Test::Unit::TestCase
+  class AssertSelectController < ActionController::Base
+    def response_with=(content)
+      @content = content
+    end
+
+    def response_with(&block)
+      @update = block
+    end
+
+    def html()
+      render :text=>@content, :layout=>false, :content_type=>Mime::HTML
+      @content = nil
+    end
+
+    def rjs()
+      render :update do |page|
+        @update.call page
+      end
+      @update = nil
+    end
+
+    def xml()
+      render :text=>@content, :layout=>false, :content_type=>Mime::XML
+      @content = nil
+    end
+
+    def rescue_action(e)
+      raise e
+    end
+  end
+
+  class AssertSelectMailer < ActionMailer::Base
+    def test(html)
+      recipients "test <test@test.host>"
+      from "test@test.host"
+      subject "Test e-mail"
+      part :content_type=>"text/html", :body=>html
+    end
+  end
+
+  AssertionFailedError = Test::Unit::AssertionFailedError
+
+  def setup
+    @controller = AssertSelectController.new
+    @request    = ActionController::TestRequest.new
+    @response   = ActionController::TestResponse.new
+    ActionMailer::Base.delivery_method = :test
+    ActionMailer::Base.perform_deliveries = true
+    ActionMailer::Base.deliveries = []
+  end
+
+
+  def teardown
+    ActionMailer::Base.deliveries.clear
+  end
+
+
+  #
+  # Test assert select.
+  #
+
+  def test_assert_select
+    render_html %Q{<div id="1"></div><div id="2"></div>}
+    assert_select "div", 2
+    assert_raises(AssertionFailedError) { assert_select "div", 3 }
+    assert_raises(AssertionFailedError){ assert_select "p" }
+  end
+
+
+  def test_equality_true_false
+    render_html %Q{<div id="1"></div><div id="2"></div>}
+    assert_nothing_raised               { assert_select "div" }
+    assert_raises(AssertionFailedError) { assert_select "p" }
+    assert_nothing_raised               { assert_select "div", true }
+    assert_raises(AssertionFailedError) { assert_select "p", true }
+    assert_raises(AssertionFailedError) { assert_select "div", false }
+    assert_nothing_raised               { assert_select "p", false }
+  end
+
+
+  def test_equality_string_and_regexp
+    render_html %Q{<div id="1">foo</div><div id="2">foo</div>}
+    assert_nothing_raised               { assert_select "div", "foo" }
+    assert_raises(AssertionFailedError) { assert_select "div", "bar" }
+    assert_nothing_raised               { assert_select "div", :text=>"foo" }
+    assert_raises(AssertionFailedError) { assert_select "div", :text=>"bar" }
+    assert_nothing_raised               { assert_select "div", /(foo|bar)/ }
+    assert_raises(AssertionFailedError) { assert_select "div", /foobar/ }
+    assert_nothing_raised               { assert_select "div", :text=>/(foo|bar)/ }
+    assert_raises(AssertionFailedError) { assert_select "div", :text=>/foobar/ }
+    assert_raises(AssertionFailedError) { assert_select "p", :text=>/foobar/ }
+  end
+
+
+  def test_equality_of_html
+    render_html %Q{<p>\n<em>"This is <strong>not</strong> a big problem,"</em> he said.\n</p>}
+    text = "\"This is not a big problem,\" he said."
+    html = "<em>\"This is <strong>not</strong> a big problem,\"</em> he said."
+    assert_nothing_raised               { assert_select "p", text }
+    assert_raises(AssertionFailedError) { assert_select "p", html }
+    assert_nothing_raised               { assert_select "p", :html=>html }
+    assert_raises(AssertionFailedError) { assert_select "p", :html=>text }
+    # No stripping for pre.
+    render_html %Q{<pre>\n<em>"This is <strong>not</strong> a big problem,"</em> he said.\n</pre>}
+    text = "\n\"This is not a big problem,\" he said.\n"
+    html = "\n<em>\"This is <strong>not</strong> a big problem,\"</em> he said.\n"
+    assert_nothing_raised               { assert_select "pre", text }
+    assert_raises(AssertionFailedError) { assert_select "pre", html }
+    assert_nothing_raised               { assert_select "pre", :html=>html }
+    assert_raises(AssertionFailedError) { assert_select "pre", :html=>text }
+  end
+
+
+  def test_equality_of_instances
+    render_html %Q{<div id="1">foo</div><div id="2">foo</div>}
+    assert_nothing_raised               { assert_select "div", 2 }
+    assert_raises(AssertionFailedError) { assert_select "div", 3 }
+    assert_nothing_raised               { assert_select "div", 1..2 }
+    assert_raises(AssertionFailedError) { assert_select "div", 3..4 }
+    assert_nothing_raised               { assert_select "div", :count=>2 }
+    assert_raises(AssertionFailedError) { assert_select "div", :count=>3 }
+    assert_nothing_raised               { assert_select "div", :minimum=>1 }
+    assert_nothing_raised               { assert_select "div", :minimum=>2 }
+    assert_raises(AssertionFailedError) { assert_select "div", :minimum=>3 }
+    assert_nothing_raised               { assert_select "div", :maximum=>2 }
+    assert_nothing_raised               { assert_select "div", :maximum=>3 }
+    assert_raises(AssertionFailedError) { assert_select "div", :maximum=>1 }
+    assert_nothing_raised               { assert_select "div", :minimum=>1, :maximum=>2 }
+    assert_raises(AssertionFailedError) { assert_select "div", :minimum=>3, :maximum=>4 }
+  end
+
+
+  def test_substitution_values
+    render_html %Q{<div id="1">foo</div><div id="2">foo</div>}
+    assert_select "div#?", /\d+/ do |elements|
+      assert_equal 2, elements.size
+    end
+    assert_select "div" do
+      assert_select "div#?", /\d+/ do |elements|
+        assert_equal 2, elements.size
+        assert_select "#1"
+        assert_select "#2"
+      end
+    end
+  end
+
+  
+  def test_nested_assert_select
+    render_html %Q{<div id="1">foo</div><div id="2">foo</div>}
+    assert_select "div" do |elements|
+      assert_equal 2, elements.size
+      assert_select elements[0], "#1"
+      assert_select elements[1], "#2"
+    end
+    assert_select "div" do
+      assert_select "div" do |elements|
+        assert_equal 2, elements.size
+        # Testing in a group is one thing
+        assert_select "#1,#2"
+        # Testing individually is another.
+        assert_select "#1"
+        assert_select "#2"
+        assert_select "#3", false
+      end
+    end
+  end
+
+
+  def test_assert_select_from_rjs
+    render_rjs do |page|
+      page.replace_html "test", "<div id=\"1\">foo</div>\n<div id=\"2\">foo</div>"
+    end
+    assert_select "div" do |elements|
+      assert elements.size == 2
+      assert_select "#1"
+      assert_select "#2"
+    end
+    assert_select "div#?", /\d+/ do |elements|
+      assert_select "#1"
+      assert_select "#2"
+    end
+    # With multiple results.
+    render_rjs do |page|
+      page.replace_html "test", "<div id=\"1\">foo</div>"
+      page.replace_html "test2", "<div id=\"2\">foo</div>"
+    end
+    assert_select "div" do |elements|
+      assert elements.size == 2
+      assert_select "#1"
+      assert_select "#2"
+    end
+  end
+
+
+  #
+  # Test css_select.
+  #
+
+
+  def test_css_select
+    render_html %Q{<div id="1"></div><div id="2"></div>}
+    assert 2, css_select("div").size
+    assert 0, css_select("p").size
+  end
+
+
+  def test_nested_css_select
+    render_html %Q{<div id="1">foo</div><div id="2">foo</div>}
+    assert_select "div#?", /\d+/ do |elements|
+      assert_equal 1, css_select(elements[0], "div").size
+      assert_equal 1, css_select(elements[1], "div").size
+    end
+    assert_select "div" do
+      assert_equal 2, css_select("div").size
+      css_select("div").each do |element|
+        # Testing as a group is one thing
+        assert !css_select("#1,#2").empty?
+        # Testing individually is another
+        assert !css_select("#1").empty?
+        assert !css_select("#2").empty?
+      end
+    end
+  end
+
+
+  def test_css_select_from_rjs
+    # With one result.
+    render_rjs do |page|
+      page.replace_html "test", "<div id=\"1\">foo</div>\n<div id=\"2\">foo</div>"
+    end
+    assert_equal 2, css_select("div").size
+    assert_equal 1, css_select("#1").size
+    assert_equal 1, css_select("#2").size
+    # With multiple results.
+    render_rjs do |page|
+      page.replace_html "test", "<div id=\"1\">foo</div>"
+      page.replace_html "test2", "<div id=\"2\">foo</div>"
+    end
+    assert_equal 2, css_select("div").size
+    assert_equal 1, css_select("#1").size
+    assert_equal 1, css_select("#2").size
+  end
+
+
+  #
+  # Test assert_select_rjs.
+  #
+
+
+  def test_assert_select_rjs
+    # Test that we can pick up all statements in the result.
+    render_rjs do |page|
+      page.replace "test", "<div id=\"1\">foo</div>"
+      page.replace_html "test2", "<div id=\"2\">foo</div>"
+      page.insert_html :top, "test3", "<div id=\"3\">foo</div>"
+    end
+    found = false
+    assert_select_rjs do
+      assert_select "#1"
+      assert_select "#2"
+      assert_select "#3"
+      found = true
+    end
+    assert found
+    # Test that we fail if there is nothing to pick.
+    render_rjs do |page|
+    end
+    assert_raises(AssertionFailedError) { assert_select_rjs }
+  end
+
+
+  def test_assert_select_rjs_with_id
+    # Test that we can pick up all statements in the result.
+    render_rjs do |page|
+      page.replace "test1", "<div id=\"1\">foo</div>"
+      page.replace_html "test2", "<div id=\"2\">foo</div>"
+      page.insert_html :top, "test3", "<div id=\"3\">foo</div>"
+    end
+    assert_select_rjs "test1" do
+      assert_select "div", 1
+      assert_select "#1"
+    end
+    assert_select_rjs "test2" do
+      assert_select "div", 1
+      assert_select "#2"
+    end
+    assert_select_rjs "test3" do
+      assert_select "div", 1
+      assert_select "#3"
+    end
+    assert_raises(AssertionFailedError) { assert_select_rjs "test4" }
+  end
+
+
+  def test_assert_select_rjs_for_replace
+    render_rjs do |page|
+      page.replace "test1", "<div id=\"1\">foo</div>"
+      page.replace_html "test2", "<div id=\"2\">foo</div>"
+      page.insert_html :top, "test3", "<div id=\"3\">foo</div>"
+    end
+    # Replace.
+    assert_select_rjs :replace do
+      assert_select "div", 1
+      assert_select "#1"
+    end
+    assert_select_rjs :replace, "test1" do
+      assert_select "div", 1
+      assert_select "#1"
+    end
+    assert_raises(AssertionFailedError) { assert_select_rjs :replace, "test2" }
+    # Replace HTML.
+    assert_select_rjs :replace_html do
+      assert_select "div", 1
+      assert_select "#2"
+    end
+    assert_select_rjs :replace_html, "test2" do
+      assert_select "div", 1
+      assert_select "#2"
+    end
+    assert_raises(AssertionFailedError) { assert_select_rjs :replace_html, "test1" }
+  end
+
+
+  def test_assert_select_rjs_for_insert
+    render_rjs do |page|
+      page.replace "test1", "<div id=\"1\">foo</div>"
+      page.replace_html "test2", "<div id=\"2\">foo</div>"
+      page.insert_html :top, "test3", "<div id=\"3\">foo</div>"
+    end
+    # Non-positioned.
+    assert_select_rjs :insert_html do
+      assert_select "div", 1
+      assert_select "#3"
+    end
+    assert_select_rjs :insert_html, "test3" do
+      assert_select "div", 1
+      assert_select "#3"
+    end
+    assert_raises(AssertionFailedError) { assert_select_rjs :insert_html, "test1" }
+    # Positioned.
+    render_rjs do |page|
+      page.insert_html :top, "test1", "<div id=\"1\">foo</div>"
+      page.insert_html :bottom, "test2", "<div id=\"2\">foo</div>"
+      page.insert_html :before, "test3", "<div id=\"3\">foo</div>"
+      page.insert_html :after, "test4", "<div id=\"4\">foo</div>"
+    end
+    assert_select_rjs :insert, :top do
+      assert_select "div", 1
+      assert_select "#1"
+    end
+    assert_select_rjs :insert, :bottom do
+      assert_select "div", 1
+      assert_select "#2"
+    end
+    assert_select_rjs :insert, :before do
+      assert_select "div", 1
+      assert_select "#3"
+    end
+    assert_select_rjs :insert, :after do
+      assert_select "div", 1
+      assert_select "#4"
+    end
+    assert_select_rjs :insert_html do
+      assert_select "div", 4
+    end
+  end
+
+
+  def test_nested_assert_select_rjs
+    # Simple selection from a single result.
+    render_rjs do |page|
+      page.replace_html "test", "<div id=\"1\">foo</div>\n<div id=\"2\">foo</div>"
+    end
+    assert_select_rjs "test" do |elements|
+      assert_equal 2, elements.size
+      assert_select "#1"
+      assert_select "#2"
+    end
+    # Deal with two results.
+    render_rjs do |page|
+      page.replace_html "test", "<div id=\"1\">foo</div>"
+      page.replace_html "test2", "<div id=\"2\">foo</div>"
+    end
+    assert_select_rjs "test" do |elements|
+      assert_equal 1, elements.size
+      assert_select "#1"
+    end
+    assert_select_rjs "test2" do |elements|
+      assert_equal 1, elements.size
+      assert_select "#2"
+    end
+  end
+
+
+  def test_feed_item_encoded
+    render_xml <<-EOF
+<rss version="2.0">
+  <channel>
+    <item>
+      <description>
+        <![CDATA[
+          <p>Test 1</p>
+        ]]>
+      </description>
+    </item>
+    <item>
+      <description>
+        <![CDATA[
+          <p>Test 2</p>
+        ]]>
+      </description>
+    </item>
+  </channel>
+</rss>
+EOF
+    assert_select "channel item description" do
+      # Test element regardless of wrapper.
+      assert_select_encoded do
+        assert_select "p", :count=>2, :text=>/Test/
+      end
+      # Test through encoded wrapper.
+      assert_select_encoded do
+        assert_select "encoded p", :count=>2, :text=>/Test/
+      end
+      # Use :root instead (recommended)
+      assert_select_encoded do
+        assert_select ":root p", :count=>2, :text=>/Test/
+      end
+      # Test individually.
+      assert_select "description" do |elements|
+        assert_select_encoded elements[0] do
+          assert_select "p", "Test 1"
+        end
+        assert_select_encoded elements[1] do
+          assert_select "p", "Test 2"
+        end
+      end
+    end
+
+    # Test that we only un-encode element itself.
+    assert_select "channel item" do
+      assert_select_encoded do
+        assert_select "p", 0
+      end
+    end
+  end
+
+
+  #
+  # Test assert_select_email
+  #
+
+  def test_assert_select_email
+    assert_raises(AssertionFailedError) { assert_select_email {} }
+    AssertSelectMailer.deliver_test "<div><p>foo</p><p>bar</p></div>"
+    assert_select_email do
+      assert_select "div:root" do
+        assert_select "p:first-child", "foo"
+        assert_select "p:last-child", "bar"
+      end
+    end
+  end
+
+
+  protected
+    def render_html(html)
+      @controller.response_with = html
+      get :html
+    end
+
+    def render_rjs(&block)
+      @controller.response_with &block
+      get :rjs
+    end
+
+    def render_xml(xml)
+      @controller.response_with = xml
+      get :xml
+    end
+end
\ No newline at end of file
diff --git a/actionpack/test/controller/selector_test.rb b/actionpack/test/controller/selector_test.rb
new file mode 100644
index 0000000000..d004290097
--- /dev/null
+++ b/actionpack/test/controller/selector_test.rb
@@ -0,0 +1,628 @@
+#--
+# Copyright (c) 2006 Assaf Arkin (http://labnotes.org)
+# Under MIT and/or CC By license.
+#++
+
+require File.dirname(__FILE__) + '/../abstract_unit'
+require File.dirname(__FILE__) + '/fake_controllers'
+
+class SelectorTest < Test::Unit::TestCase
+  #
+  # Basic selector: element, id, class, attributes.
+  #
+
+  def test_element
+    parse(%Q{<div id="1"></div><p></p><div id="2"></div>})
+    # Match element by name.
+    select("div")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "2", @matches[1].attributes["id"]
+    # Not case sensitive.
+    select("DIV")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "2", @matches[1].attributes["id"]
+    # Universal match (all elements).
+    select("*")
+    assert_equal 3, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal nil, @matches[1].attributes["id"]
+    assert_equal "2", @matches[2].attributes["id"]
+  end
+
+
+  def test_identifier
+    parse(%Q{<div id="1"></div><p></p><div id="2"></div>})
+    # Match element by ID.
+    select("div#1")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    # Match element by ID, substitute value.
+    select("div#?", 2)
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    # Element name does not match ID.
+    select("p#?", 2)
+    assert_equal 0, @matches.size
+    # Use regular expression.
+    select("#?", /\d/)
+    assert_equal 2, @matches.size
+  end
+
+
+  def test_class_name
+    parse(%Q{<div id="1" class=" foo "></div><p id="2" class=" foo bar "></p><div id="3" class="bar"></div>})
+    # Match element with specified class.
+    select("div.foo")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    # Match any element with specified class.
+    select("*.foo")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "2", @matches[1].attributes["id"]
+    # Match elements with other class.
+    select("*.bar")
+    assert_equal 2, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    assert_equal "3", @matches[1].attributes["id"]
+    # Match only element with both class names.
+    select("*.bar.foo")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+  end
+
+
+  def test_attribute
+    parse(%Q{<div id="1"></div><p id="2" title="" bar="foo"></p><div id="3" title="foo"></div>})
+    # Match element with attribute.
+    select("div[title]")
+    assert_equal 1, @matches.size
+    assert_equal "3", @matches[0].attributes["id"]
+    # Match any element with attribute.
+    select("*[title]")
+    assert_equal 2, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    assert_equal "3", @matches[1].attributes["id"]
+    # Match alement with attribute value.
+    select("*[title=foo]")
+    assert_equal 1, @matches.size
+    assert_equal "3", @matches[0].attributes["id"]
+    # Match alement with attribute and attribute value.
+    select("[bar=foo][title]")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    # Not case sensitive.
+    select("[BAR=foo][TiTle]")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+  end
+
+
+  def test_attribute_quoted
+    parse(%Q{<div id="1" title="foo"></div><div id="2" title="bar"></div><div id="3" title="  bar  "></div>})
+    # Match without quotes.
+    select("[title = bar]")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    # Match with single quotes.
+    select("[title = 'bar' ]")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    # Match with double quotes.
+    select("[title = \"bar\" ]")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    # Match with spaces.
+    select("[title = \"  bar  \" ]")
+    assert_equal 1, @matches.size
+    assert_equal "3", @matches[0].attributes["id"]
+  end
+
+
+  def test_attribute_equality
+    parse(%Q{<div id="1" title="foo bar"></div><div id="2" title="barbaz"></div>})
+    # Match (fail) complete value.
+    select("[title=bar]")
+    assert_equal 0, @matches.size
+    # Match space-separate word.
+    select("[title~=foo]")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    select("[title~=bar]")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    # Match beginning of value.
+    select("[title^=ba]")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    # Match end of value.
+    select("[title$=ar]")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    # Match text in value.
+    select("[title*=bar]")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "2", @matches[1].attributes["id"]
+    # Match first space separated word.
+    select("[title|=foo]")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    select("[title|=bar]")
+    assert_equal 0, @matches.size
+  end
+
+
+  #
+  # Selector composition: groups, sibling, children
+  #
+
+
+  def test_selector_group
+    parse(%Q{<h1 id="1"></h1><h2 id="2"></h2><h3 id="3"></h3>})
+    # Simple group selector.
+    select("h1,h3")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "3", @matches[1].attributes["id"]
+    select("h1 , h3")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "3", @matches[1].attributes["id"]
+    # Complex group selector.
+    parse(%Q{<h1 id="1"><a href="foo"></a></h1><h2 id="2"><a href="bar"></a></h2><h3 id="2"><a href="baz"></a></h3>})
+    select("h1 a, h3 a")
+    assert_equal 2, @matches.size
+    assert_equal "foo", @matches[0].attributes["href"]
+    assert_equal "baz", @matches[1].attributes["href"]
+    # And now for the three selector challange.
+    parse(%Q{<h1 id="1"><a href="foo"></a></h1><h2 id="2"><a href="bar"></a></h2><h3 id="2"><a href="baz"></a></h3>})
+    select("h1 a, h2 a, h3 a")
+    assert_equal 3, @matches.size
+    assert_equal "foo", @matches[0].attributes["href"]
+    assert_equal "bar", @matches[1].attributes["href"]
+    assert_equal "baz", @matches[2].attributes["href"]
+  end
+
+
+  def test_sibling_selector
+    parse(%Q{<h1 id="1"></h1><h2 id="2"></h2><h3 id="3"></h3>})
+    # Test next sibling.
+    select("h1+*")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    select("h1+h2")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    select("h1+h3")
+    assert_equal 0, @matches.size
+    select("*+h3")
+    assert_equal 1, @matches.size
+    assert_equal "3", @matches[0].attributes["id"]
+    # Test any sibling.
+    select("h1~*")
+    assert_equal 2, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    assert_equal "3", @matches[1].attributes["id"]
+    select("h2~*")
+    assert_equal 1, @matches.size
+    assert_equal "3", @matches[0].attributes["id"]
+  end
+
+
+  def test_children_selector
+    parse(%Q{<div><p id="1"><span id="2"></span></p></div><div><p id="3"><span id="4" class="foo"></span></p></div>})
+    # Test child selector.
+    select("div>p")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "3", @matches[1].attributes["id"]
+    select("div>span")
+    assert_equal 0, @matches.size
+    select("div>p#3")
+    assert_equal 1, @matches.size
+    assert_equal "3", @matches[0].attributes["id"]
+    select("div>p>span")
+    assert_equal 2, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    assert_equal "4", @matches[1].attributes["id"]
+    # Test descendant selector.
+    select("div p")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "3", @matches[1].attributes["id"]
+    select("div span")
+    assert_equal 2, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    assert_equal "4", @matches[1].attributes["id"]
+    select("div *#3")
+    assert_equal 1, @matches.size
+    assert_equal "3", @matches[0].attributes["id"]
+    select("div *#4")
+    assert_equal 1, @matches.size
+    assert_equal "4", @matches[0].attributes["id"]
+    # This is here because it failed before when whitespaces
+    # were not properly stripped.
+    select("div .foo")
+    assert_equal 1, @matches.size
+    assert_equal "4", @matches[0].attributes["id"]
+  end
+
+
+  #
+  # Pseudo selectors: root, nth-child, empty, content, etc
+  #
+
+
+  def test_root_selector
+    parse(%Q{<div id="1"><div id="2"></div></div>})
+    # Can only find element if it's root.
+    select(":root")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    select("#1:root")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    select("#2:root")
+    assert_equal 0, @matches.size
+    # Opposite for nth-child.
+    select("#1:nth-child(1)")
+    assert_equal 0, @matches.size
+  end
+
+
+  def test_nth_child_odd_even
+    parse(%Q{<table><tr id="1"></tr><tr id="2"></tr><tr id="3"></tr><tr id="4"></tr></table>})
+    # Test odd nth children.
+    select("tr:nth-child(odd)")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "3", @matches[1].attributes["id"]
+    # Test even nth children.
+    select("tr:nth-child(even)")
+    assert_equal 2, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    assert_equal "4", @matches[1].attributes["id"]
+  end
+
+
+  def test_nth_child_a_is_zero
+    parse(%Q{<table><tr id="1"></tr><tr id="2"></tr><tr id="3"></tr><tr id="4"></tr></table>})
+    # Test the third child.
+    select("tr:nth-child(0n+3)")
+    assert_equal 1, @matches.size
+    assert_equal "3", @matches[0].attributes["id"]
+    # Same but an can be omitted when zero.
+    select("tr:nth-child(3)")
+    assert_equal 1, @matches.size
+    assert_equal "3", @matches[0].attributes["id"]
+    # Second element (but not every second element).
+    select("tr:nth-child(0n+2)")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    # Before first and past last returns nothing.:
+    assert_raises(ArgumentError) { select("tr:nth-child(-1)") }
+    select("tr:nth-child(0)")
+    assert_equal 0, @matches.size
+    select("tr:nth-child(5)")
+    assert_equal 0, @matches.size
+  end
+
+
+  def test_nth_child_a_is_one
+    parse(%Q{<table><tr id="1"></tr><tr id="2"></tr><tr id="3"></tr><tr id="4"></tr></table>})
+    # a is group of one, pick every element in group.
+    select("tr:nth-child(1n+0)")
+    assert_equal 4, @matches.size
+    # Same but a can be omitted when one.
+    select("tr:nth-child(n+0)")
+    assert_equal 4, @matches.size
+    # Same but b can be omitted when zero.
+    select("tr:nth-child(n)")
+    assert_equal 4, @matches.size
+  end
+
+
+  def test_nth_child_b_is_zero
+    parse(%Q{<table><tr id="1"></tr><tr id="2"></tr><tr id="3"></tr><tr id="4"></tr></table>})
+    # If b is zero, pick the n-th element (here each one).
+    select("tr:nth-child(n+0)")
+    assert_equal 4, @matches.size
+    # If b is zero, pick the n-th element (here every second).
+    select("tr:nth-child(2n+0)")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "3", @matches[1].attributes["id"]
+    # If a and b are both zero, no element selected.
+    select("tr:nth-child(0n+0)")
+    assert_equal 0, @matches.size
+    select("tr:nth-child(0)")
+    assert_equal 0, @matches.size
+  end
+
+
+  def test_nth_child_a_is_negative
+    parse(%Q{<table><tr id="1"></tr><tr id="2"></tr><tr id="3"></tr><tr id="4"></tr></table>})
+    # Since a is -1, picks the first three elements.
+    select("tr:nth-child(-n+3)")
+    assert_equal 3, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "2", @matches[1].attributes["id"]
+    assert_equal "3", @matches[2].attributes["id"]
+    # Since a is -2, picks the first in every second of first four elements.
+    select("tr:nth-child(-2n+3)")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "3", @matches[1].attributes["id"]
+    # Since a is -2, picks the first in every second of first three elements.
+    select("tr:nth-child(-2n+2)")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+  end
+
+
+  def test_nth_child_b_is_negative
+    parse(%Q{<table><tr id="1"></tr><tr id="2"></tr><tr id="3"></tr><tr id="4"></tr></table>})
+    # Select last of four.
+    select("tr:nth-child(4n-1)")
+    assert_equal 1, @matches.size
+    assert_equal "4", @matches[0].attributes["id"]
+    # Select first of four.
+    select("tr:nth-child(4n-4)")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    # Select last of every second.
+    select("tr:nth-child(2n-1)")
+    assert_equal 2, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    assert_equal "4", @matches[1].attributes["id"]
+    # Select nothing since an+b always < 0
+    select("tr:nth-child(-1n-1)")
+    assert_equal 0, @matches.size
+  end
+
+
+  def test_nth_child_substitution_values
+    parse(%Q{<table><tr id="1"></tr><tr id="2"></tr><tr id="3"></tr><tr id="4"></tr></table>})
+    # Test with ?n?.
+    select("tr:nth-child(?n?)", 2, 1)
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "3", @matches[1].attributes["id"]
+    select("tr:nth-child(?n?)", 2, 2)
+    assert_equal 2, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    assert_equal "4", @matches[1].attributes["id"]
+    select("tr:nth-child(?n?)", 4, 2)
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    # Test with ? (b only).
+    select("tr:nth-child(?)", 3)
+    assert_equal 1, @matches.size
+    assert_equal "3", @matches[0].attributes["id"]
+    select("tr:nth-child(?)", 5)
+    assert_equal 0, @matches.size
+  end
+
+
+  def test_nth_last_child
+    parse(%Q{<table><tr id="1"></tr><tr id="2"></tr><tr id="3"></tr><tr id="4"></tr></table>})
+    # Last two elements.
+    select("tr:nth-last-child(-n+2)")
+    assert_equal 2, @matches.size
+    assert_equal "3", @matches[0].attributes["id"]
+    assert_equal "4", @matches[1].attributes["id"]
+    # All old elements counting from last one.
+    select("tr:nth-last-child(odd)")
+    assert_equal 2, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    assert_equal "4", @matches[1].attributes["id"]
+  end
+
+
+  def test_nth_of_type
+    parse(%Q{<table><thead></thead><tr id="1"></tr><tr id="2"></tr><tr id="3"></tr><tr id="4"></tr></table>})
+    # First two elements.
+    select("tr:nth-of-type(-n+2)")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "2", @matches[1].attributes["id"]
+    # All old elements counting from last one.
+    select("tr:nth-last-of-type(odd)")
+    assert_equal 2, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    assert_equal "4", @matches[1].attributes["id"]
+  end
+
+  
+  def test_first_and_last
+    parse(%Q{<table><thead></thead><tr id="1"></tr><tr id="2"></tr><tr id="3"></tr><tr id="4"></tr></table>})
+    # First child.
+    select("tr:first-child")
+    assert_equal 0, @matches.size
+    select(":first-child")
+    assert_equal 1, @matches.size
+    assert_equal "thead", @matches[0].name
+    # First of type.
+    select("tr:first-of-type")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    select("thead:first-of-type")
+    assert_equal 1, @matches.size
+    assert_equal "thead", @matches[0].name
+    select("div:first-of-type")
+    assert_equal 0, @matches.size
+    # Last child.
+    select("tr:last-child")
+    assert_equal 1, @matches.size
+    assert_equal "4", @matches[0].attributes["id"]
+    # Last of type.
+    select("tr:last-of-type")
+    assert_equal 1, @matches.size
+    assert_equal "4", @matches[0].attributes["id"]
+    select("thead:last-of-type")
+    assert_equal 1, @matches.size
+    assert_equal "thead", @matches[0].name
+    select("div:last-of-type")
+    assert_equal 0, @matches.size
+  end
+
+
+  def test_first_and_last
+    # Only child.
+    parse(%Q{<table><tr></tr></table>})
+    select("table:only-child")
+    assert_equal 0, @matches.size
+    select("tr:only-child")
+    assert_equal 1, @matches.size
+    assert_equal "tr", @matches[0].name
+    parse(%Q{<table><tr></tr><tr></tr></table>})
+    select("tr:only-child")
+    assert_equal 0, @matches.size
+    # Only of type.
+    parse(%Q{<table><thead></thead><tr></tr><tr></tr></table>})
+    select("thead:only-of-type")
+    assert_equal 1, @matches.size
+    assert_equal "thead", @matches[0].name
+    select("td:only-of-type")
+    assert_equal 0, @matches.size
+  end
+
+
+  def test_empty
+    parse(%Q{<table><tr></tr></table>})
+    select("table:empty")
+    assert_equal 0, @matches.size
+    select("tr:empty")
+    assert_equal 1, @matches.size
+    parse(%Q{<div> </div>})
+    select("div:empty")
+    assert_equal 1, @matches.size
+  end
+
+  
+  def test_content
+    parse(%Q{<div> </div>})
+    select("div:content()")
+    assert_equal 1, @matches.size
+    parse(%Q{<div>something </div>})
+    select("div:content()")
+    assert_equal 0, @matches.size
+    select("div:content(something)")
+    assert_equal 1, @matches.size
+    select("div:content( 'something' )")
+    assert_equal 1, @matches.size
+    select("div:content( \"something\" )")
+    assert_equal 1, @matches.size
+    select("div:content(?)", "something")
+    assert_equal 1, @matches.size
+    select("div:content(?)", /something/)
+    assert_equal 1, @matches.size
+  end
+
+
+  #
+  # Test negation.
+  #
+
+
+  def test_element_negation
+    parse(%Q{<p></p><div></div>})
+    select("*")
+    assert_equal 2, @matches.size
+    select("*:not(p)")
+    assert_equal 1, @matches.size
+    assert_equal "div", @matches[0].name
+    select("*:not(div)")
+    assert_equal 1, @matches.size
+    assert_equal "p", @matches[0].name
+    select("*:not(span)")
+    assert_equal 2, @matches.size
+  end
+
+
+  def test_id_negation
+    parse(%Q{<p id="1"></p><p id="2"></p>})
+    select("p")
+    assert_equal 2, @matches.size
+    select(":not(#1)")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    select(":not(#2)")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+  end
+
+
+  def test_class_name_negation
+    parse(%Q{<p class="foo"></p><p class="bar"></p>})
+    select("p")
+    assert_equal 2, @matches.size
+    select(":not(.foo)")
+    assert_equal 1, @matches.size
+    assert_equal "bar", @matches[0].attributes["class"]
+    select(":not(.bar)")
+    assert_equal 1, @matches.size
+    assert_equal "foo", @matches[0].attributes["class"]
+  end
+
+
+  def test_attribute_negation
+    parse(%Q{<p title="foo"></p><p title="bar"></p>})
+    select("p")
+    assert_equal 2, @matches.size
+    select(":not([title=foo])")
+    assert_equal 1, @matches.size
+    assert_equal "bar", @matches[0].attributes["title"]
+    select(":not([title=bar])")
+    assert_equal 1, @matches.size
+    assert_equal "foo", @matches[0].attributes["title"]
+  end
+
+  
+  def test_pseudo_class_negation
+    parse(%Q{<div><p id="1"></p><p id="2"></p></div>})
+    select("p")
+    assert_equal 2, @matches.size
+    select("p:not(:first-child)")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+    select("p:not(:nth-child(2))")
+    assert_equal 1, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+  end
+  
+
+  def test_negation_details
+    parse(%Q{<p id="1"></p><p id="2"></p><p id="3"></p>})
+    assert_raises(ArgumentError) { select(":not(") }
+    assert_raises(ArgumentError) { select(":not(:not())") }
+    select("p:not(#1):not(#3)")
+    assert_equal 1, @matches.size
+    assert_equal "2", @matches[0].attributes["id"]
+  end
+
+
+  def test_select_from_element
+    parse(%Q{<div><p id="1"></p><p id="2"></p></div>})
+    select("div")
+    @matches = @matches[0].select("p")
+    assert_equal 2, @matches.size
+    assert_equal "1", @matches[0].attributes["id"]
+    assert_equal "2", @matches[1].attributes["id"]
+  end
+
+
+protected
+
+  def parse(html)
+    @html = HTML::Document.new(html).root
+  end
+
+  def select(*selector)
+    @matches = HTML.selector(*selector).select(@html)
+  end
+
+end