Generalize https filter

lib/html/pipeline/https_filter.rb

@@ -1,13 +1,22 @@
 module HTML
   class Pipeline
-    # HTML Filter for replacing http github urls with https versions.
+    # HTML Filter for replacing http references to :base_url with https versions.
+    # Subdomain references are not rewritten.
+    #
+    # Context options:
+    #   :base_url - The url to force https
     class HttpsFilter < Filter
       def call
-        doc.css('a[href^="http://github.com"]').each do |element|
+        doc.css(%Q(a[href^="#{context[:base_url]}"])).each do |element|
           element['href'] = element['href'].sub(/^http:/,'https:')
         end
         doc
       end
+
+      # Raise error if :base_url undefined
+      def validate
+        needs :base_url
+      end
     end
   end
-end
+end

test/html/pipeline/https_filter_test.rb

@@ -0,0 +1,34 @@
+require "test_helper"
+
+HttpsFilter = HTML::Pipeline::HttpsFilter
+
+class HTML::Pipeline::AutolinkFilterTest < Test::Unit::TestCase
+  def filter(html, base_url="http://github.com")
+    HttpsFilter.to_html(html, :base_url => base_url)
+  end
+
+  def test_http
+    assert_equal %(<a href="https://github.com">github.com</a>),
+          filter(%(<a href="http://github.com">github.com</a>))
+  end
+
+  def test_https
+    assert_equal %(<a href="https://github.com">github.com</a>),
+          filter(%(<a href="https://github.com">github.com</a>))
+  end
+
+  def test_subdomain
+    assert_equal %(<a href="http://help.github.com">github.com</a>),
+          filter(%(<a href="http://help.github.com">github.com</a>))
+  end
+
+  def test_other
+    assert_equal %(<a href="http://github.io">github.io</a>),
+          filter(%(<a href="http://github.io">github.io</a>))
+  end
+
+  def test_validation
+    exception = assert_raise(ArgumentError) { HttpsFilter.call(nil, {}) }
+    assert_match "HTML::Pipeline::HttpsFilter: :base_url", exception.message
+  end
+end