Added short_domains argument to initialize.

Added short_domains argument to initialize method to accept Booleans.
This is false by default, and if you set it to true, Rinku::AUTOLINK_SHORT_DOMAINS will be set to the flags argument of Rinku.auto_link.

lib/auto_html/link.rb

@@ -7,13 +7,14 @@
 module AutoHtml
   # Link filter
   class Link
-    def initialize(target: nil, rel: nil)
+    def initialize(target: nil, rel: nil, short_domains: false)
       @target = target
       @rel = rel
+      @short_domains = short_domains
     end
 
     def call(text)
-      Rinku.auto_link(text, :all, attributes)
+      Rinku.auto_link(text, :all, attributes, nil, flags)
     end
 
     private
@@ -29,5 +30,9 @@ def rel_attr
     def target_attr
       %(target="#{@target}") if @target
     end
+
+    def flags
+      @short_domains ? Rinku::AUTOLINK_SHORT_DOMAINS : 0
+    end
   end
 end

spec/auto_html/link_spec.rb

@@ -33,6 +33,11 @@
     expect(result).to eq '<a href="http://www.google.com/#q=nikola+tesla&ct=tesla09&oi=ddle&fp=Xmf0jJ9P_V0">http://www.google.com/#q=nikola+tesla&ct=tesla09&oi=ddle&fp=Xmf0jJ9P_V0</a>'
   end
 
+  it 'not transforms short domain URL' do
+    result = subject.call('http://localhost:3000')
+    expect(result).to eq 'http://localhost:3000'
+  end
+
   it 'transforms with target options' do
     filter = described_class.new(target: '_blank')
     result = filter.call('http://rors.org')
@@ -45,6 +50,12 @@
     expect(result).to eq '<a href="http://rors.org" rel="nofollow">http://rors.org</a>'
   end
 
+  it 'transforms with short_domains options' do
+    filter = described_class.new(short_domains: true)
+    result = filter.call('http://localhost:3000')
+    expect(result).to eq '<a href="http://localhost:3000">http://localhost:3000</a>'
+  end
+
   it 'transforms with target and rel options' do
     filter = described_class.new(target: '_blank', rel: 'nofollow')
     result = filter.call('http://rors.org')