Add option to disable URL normalization

README.rdoc

@@ -1,4 +1,4 @@
-{<img src="https://secure.travis-ci.org/jpmcgrath/shortener.svg?branch=master" alt="Build Status" />}[http://travis-ci.org/jpmcgrath/shortener]  
+{<img src="https://secure.travis-ci.org/jpmcgrath/shortener.svg?branch=master" alt="Build Status" />}[http://travis-ci.org/jpmcgrath/shortener]
 {<img src="https://codeclimate.com/github/jpmcgrath/shortener/badges/gpa.svg" />}[https://codeclimate.com/github/jpmcgrath/shortener]
 {<img src="https://badge.fury.io/rb/shortener.svg" alt="Gem version" />}[http://badge.fury.io/rb/shortener]
 
@@ -96,11 +96,16 @@ By default, Shortener will generate unique keys using numbers and lowercase a-z.
 the upper and lower case charset, by including the following:
 
   Shortener.charset = :alphanumcase
-  
+
 If you want to use a custom charset, you can create your own combination by creating an array of possible values, such as allowing underscore and dashes:
 
   Shortener.charset = ("a".."z").to_a + (0..9).to_a + ["-", "_"]
 
+By default, <b>Shortener assumes URLs to be valid web URLs</b> and normalizes them in an effort to make sure there are no duplicate records generated for effectively same URLs with differences of only non-effective slash etc.
+You can control this option if it interferes for any of your logic. One common case is for mobile app links or universal links where normalization can corrupt the URLs of form <tt>appname://some_route</tt>
+
+  Shortener.auto_clean_url = true
+
 == Usage
 
 To generate a Shortened URL object for the URL "http://example.com" within your controller / models do the following:
@@ -141,7 +146,7 @@ And to access those URLs:
 
 === Shortened URLs with custom unique key
 
-You can pass in your own key when generating a shortened URL. This should be unique.  
+You can pass in your own key when generating a shortened URL. This should be unique.
 
 *Important:* Custom keys can't contain characters other than those defined in *Shortener.charset*. Default is numbers and lowercase a-z (See *Configuration*).
 

app/models/shortener/shortened_url.rb

@@ -52,7 +52,8 @@ def self.generate!(destination_url, owner: nil, custom_key: nil, expires_at: nil
       scope = owner ? owner.shortened_urls : self
       creation_method = fresh ? 'create' : 'first_or_create'
 
-      scope.where(url: clean_url(destination_url), category: category).send(
+      url_to_save = Shortener.auto_clean_url ? clean_url(destination_url) : destination_url
+      scope.where(url: url_to_save, category: category).send(
         creation_method,
         custom_key: custom_key,
         expires_at: expires_at

lib/shortener.rb

@@ -41,6 +41,10 @@ module Shortener
   mattr_accessor :persist_retries
   self.persist_retries = 3
 
+  # auto_clean_url - controls url cleaning mechanism, set it to false to disable
+  mattr_accessor :auto_clean_url
+  self.auto_clean_url = true
+
   def self.key_chars
     charset.is_a?(Symbol) ? CHARSETS[charset] : charset
   end

spec/models/shortened_url_spec.rb

@@ -177,8 +177,26 @@
         it 'finds the shortened url from slashless oath' do
           expect(Shortener::ShortenedUrl.generate!(path)).to eq existing_shortened_url
         end
-        it "should look up exsiting URL" do
-          expect(Shortener::ShortenedUrl.generate!("/#{path}")).to eq existing_shortened_url
+
+        context 'with auto_clean_url enabled by default' do
+          it "looks up existing cleaned URL" do
+            expect(Shortener::ShortenedUrl.generate!("/#{path}")).to eq existing_shortened_url
+          end
+        end
+
+        context 'with auto_clean_url disabled' do
+          around do |spec|
+            tries = Shortener.auto_clean_url
+            Shortener.auto_clean_url = false
+            spec.run
+            Shortener.auto_clean_url = tries
+          end
+
+          it "does not look up existing cleaned URL" do
+            shortened_url = Shortener::ShortenedUrl.generate!("/#{path}")
+            expect(shortened_url).not_to eq existing_shortened_url
+            expect(shortened_url.url).to eq "/#{path}"
+          end
         end
       end
     end