Add option to skip creating the default index on the token attribute.

lib/mongoid/token.rb

@@ -17,7 +17,8 @@ def initialize_copy(source)
       def token(*args)
         options = Mongoid::Token::Options.new(args.extract_options!)
 
-        add_token_field_and_index(options)
+        add_token_field(options)
+        add_index(options)
         add_token_collision_resolver(options)
         set_token_callbacks(options)
 
@@ -26,9 +27,12 @@ def token(*args)
       end
 
       private
-      def add_token_field_and_index(options)
+      def add_token_field(options)
         self.field options.field_name, :type => String, :default => default_value(options)
-        self.index({ options.field_name => 1 }, { :unique => true, :sparse => true })
+      end
+
+      def add_index(options)
+        self.index({ options.field_name => 1 }, { :unique => true, :sparse => true }) unless options.skip_index?
       end
 
       def add_token_collision_resolver(options)

lib/mongoid/token/options.rb

@@ -23,6 +23,10 @@ def skip_finders?
     @options[:skip_finders]
   end
 
+  def skip_index?
+    @options[:skip_index]
+  end
+
   def override_to_param?
     @options[:override_to_param]
   end
@@ -71,6 +75,7 @@ def merge_defaults(options)
       contains: :alphanumeric,
       field_name: :token,
       skip_finders: false,
+      skip_index: false,
       override_to_param: true,
       generate_on_init: false
     }.merge(options)

mongoid_token.gemspec

@@ -14,7 +14,7 @@ Gem::Specification.new do |s|
   s.description = %q{Mongoid token is a gem for creating random, unique tokens for mongoid documents. Highly configurable and great for making URLs a little more compact.}
 
   s.rubyforge_project = "mongoid_token"
-  s.add_dependency 'mongoid', '~> 5.0.0'
+  s.add_dependency 'mongoid', '>= 5.0'
 
   s.files         = `git ls-files`.split("\n")
   s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")

spec/mongoid/token/options_spec.rb

@@ -68,6 +68,16 @@
     end
   end
 
+   describe "skip_index" do
+    it "should be an option" do
+      expect(Mongoid::Token::Options.new({:skip_index => true}).skip_index?).to eq true
+    end
+
+    it "should default to false" do
+      expect(Mongoid::Token::Options.new.skip_index?).to eq false
+    end
+  end
+
   describe "id" do
     context "when true" do
       it "returns '_id' sa the field name" do