diff --git a/.rubocop.yml b/.rubocop.yml
new file mode 100644
index 0000000..445bb72
--- /dev/null
+++ b/.rubocop.yml
@@ -0,0 +1,20 @@
+# The behavior of RuboCop can be controlled via the .rubocop.yml
+# configuration file. It makes it possible to enable/disable
+# certain cops (checks) and to alter their behavior if they accept
+# any parameters. The file can be placed either in your home
+# directory or in some project directory.
+#
+# RuboCop will start looking for the configuration file in the directory
+# where the inspected file is and continue its way up to the root directory.
+#
+# See https://github.com/rubocop-hq/rubocop/blob/master/manual/configuration.md
+#
+
+Layout/LineLength:
+  Max: 150
+  Exclude:
+    - 'spec/**/*_spec.rb'
+
+Metrics/BlockLength:
+  Exclude:
+    - 'spec/**/*_spec.rb'
diff --git a/Gemfile b/Gemfile
index 927117b..854d616 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,7 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 # Specify your gem's dependencies in rack-tracker.gemspec
 gemspec
+gem 'rubocop'
diff --git a/Rakefile b/Rakefile
index c382fee..82bb534 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,4 +1,6 @@
-require "bundler/gem_tasks"
+# frozen_string_literal: true
+
+require 'bundler/gem_tasks'
 require 'rspec/core/rake_task'
 
 RSpec::Core::RakeTask.new(:spec)
diff --git a/lib/rack/tracker.rb b/lib/rack/tracker.rb
index ed0a07e..91411a3 100644
--- a/lib/rack/tracker.rb
+++ b/lib/rack/tracker.rb
@@ -1,32 +1,34 @@
-require "rack"
-require "tilt"
-require "active_support/core_ext/class/attribute"
-require "active_support/core_ext/hash"
-require "active_support/json"
-require "active_support/inflector"
-
-require "rack/tracker/version"
-require "rack/tracker/extensions"
-require "rack/tracker/javascript_helper"
+# frozen_string_literal: true
+
+require 'rack'
+require 'tilt'
+require 'active_support/core_ext/class/attribute'
+require 'active_support/core_ext/hash'
+require 'active_support/json'
+require 'active_support/inflector'
+
+require 'rack/tracker/version'
+require 'rack/tracker/extensions'
+require 'rack/tracker/javascript_helper'
 require 'rack/tracker/railtie' if defined?(Rails)
-require "rack/tracker/handler"
-require "rack/tracker/handler_delegator"
-require "rack/tracker/controller"
-require "rack/tracker/google_analytics/google_analytics"
-require "rack/tracker/google_global/google_global"
-require "rack/tracker/google_tag_manager/google_tag_manager"
-require "rack/tracker/google_adwords_conversion/google_adwords_conversion"
-require "rack/tracker/facebook/facebook"
-require "rack/tracker/facebook_pixel/facebook_pixel"
-require "rack/tracker/vwo/vwo"
-require "rack/tracker/go_squared/go_squared"
-require "rack/tracker/criteo/criteo"
-require "rack/tracker/zanox/zanox"
-require "rack/tracker/hotjar/hotjar"
-require "rack/tracker/bing/bing"
-require "rack/tracker/hubspot/hubspot"
-require "rack/tracker/drift/drift"
-require "rack/tracker/heap/heap"
+require 'rack/tracker/handler'
+require 'rack/tracker/handler_delegator'
+require 'rack/tracker/controller'
+require 'rack/tracker/google_analytics/google_analytics'
+require 'rack/tracker/google_global/google_global'
+require 'rack/tracker/google_tag_manager/google_tag_manager'
+require 'rack/tracker/google_adwords_conversion/google_adwords_conversion'
+require 'rack/tracker/facebook/facebook'
+require 'rack/tracker/facebook_pixel/facebook_pixel'
+require 'rack/tracker/vwo/vwo'
+require 'rack/tracker/go_squared/go_squared'
+require 'rack/tracker/criteo/criteo'
+require 'rack/tracker/zanox/zanox'
+require 'rack/tracker/hotjar/hotjar'
+require 'rack/tracker/bing/bing'
+require 'rack/tracker/hubspot/hubspot'
+require 'rack/tracker/drift/drift'
+require 'rack/tracker/heap/heap'
 
 module Rack
   class Tracker
@@ -40,17 +42,16 @@ def initialize(app, &block)
     def call(env)
       @status, @headers, @body = @app.call(env)
       return [@status, @headers, @body] unless html?
+
       response = Rack::Response.new([], @status, @headers)
 
       env[EVENT_TRACKING_KEY] ||= {}
 
-      if session = env["rack.session"]
-        env[EVENT_TRACKING_KEY].deep_merge!(session.delete(EVENT_TRACKING_KEY) || {}) { |key, old, new| Array.wrap(old) + Array.wrap(new) }
+      if (session = env['rack.session'])
+        env[EVENT_TRACKING_KEY].deep_merge!(session.delete(EVENT_TRACKING_KEY) || {}) { |_key, old, new| Array.wrap(old) + Array.wrap(new) }
       end
 
-      if response.redirection? && session
-        session[EVENT_TRACKING_KEY] = env[EVENT_TRACKING_KEY]
-      end
+      session[EVENT_TRACKING_KEY] = env[EVENT_TRACKING_KEY] if response.redirection? && session
 
       @body.each { |fragment| response.write inject(env, fragment) }
       @body.close if @body.respond_to?(:close)
@@ -60,7 +61,9 @@ def call(env)
 
     private
 
-    def html?; @headers['Content-Type'] =~ /html/; end
+    def html?
+      @headers['Content-Type'] =~ /html/
+    end
 
     def inject(env, response)
       duplicated_response = response.dup
@@ -90,7 +93,7 @@ def initialize(&block)
       #     handler :google_analytics, { tracker: 'U-XXXXX-Y' }
       #   end
       #
-      def handler(name, configuration = {}, &block)
+      def handler(name, configuration = {})
         # we need here "something" (which is atm the handler struct)
         # to postpone the initialization of the handler,
         # to give it the env and configuration options when the result of the handler is injected into the response.
diff --git a/lib/rack/tracker/bing/bing.rb b/lib/rack/tracker/bing/bing.rb
index f7e71c7..d94eba5 100644
--- a/lib/rack/tracker/bing/bing.rb
+++ b/lib/rack/tracker/bing/bing.rb
@@ -1,5 +1,6 @@
-class Rack::Tracker::Bing < Rack::Tracker::Handler
+# frozen_string_literal: true
 
+class Rack::Tracker::Bing < Rack::Tracker::Handler
   class Conversion < OpenStruct
   end
 
@@ -8,5 +9,4 @@ class Conversion < OpenStruct
   def tracker
     options[:tracker].respond_to?(:call) ? options[:tracker].call(env) : options[:tracker]
   end
-
 end
diff --git a/lib/rack/tracker/controller.rb b/lib/rack/tracker/controller.rb
index 801a52a..5694626 100644
--- a/lib/rack/tracker/controller.rb
+++ b/lib/rack/tracker/controller.rb
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 module Rack
   class Tracker
     module Controller
-      def tracker(&block)
-        if block_given?
-          yield(Rack::Tracker::HandlerDelegator.new(respond_to?(:request) ? request.env : env))
-        end
+      def tracker
+        return unless block_given?
+
+        yield(Rack::Tracker::HandlerDelegator.new(respond_to?(:request) ? request.env : env))
       end
     end
   end
diff --git a/lib/rack/tracker/criteo/criteo.rb b/lib/rack/tracker/criteo/criteo.rb
index 5a71c7b..3415149 100644
--- a/lib/rack/tracker/criteo/criteo.rb
+++ b/lib/rack/tracker/criteo/criteo.rb
@@ -1,12 +1,13 @@
-class Rack::Tracker::Criteo < Rack::Tracker::Handler
+# frozen_string_literal: true
 
+class Rack::Tracker::Criteo < Rack::Tracker::Handler
   TRACKER_EVENTS = {
     # event name => event key name, e.g. { event: 'setSiteType', type: '' }
     set_site_type: :type,
     set_account: :account,
     set_customer_id: :id,
     set_email: :email
-  }
+  }.freeze
 
   class Event < OpenStruct
     def write
@@ -20,8 +21,8 @@ def write
   def tracker_events
     @tracker_events ||= [].tap do |tracker_events|
       options.slice(*TRACKER_EVENTS.keys).each do |key, value|
-        if option_value = value.respond_to?(:call) ? value.call(env) : value
-          tracker_events << Event.new(:event => "#{key}".camelize(:lower),  TRACKER_EVENTS[key] => "#{option_value}")
+        if (option_value = value.respond_to?(:call) ? value.call(env) : value)
+          tracker_events << Event.new(:event => key.to_s.camelize(:lower), TRACKER_EVENTS[key] => option_value.to_s)
         end
       end
     end
diff --git a/lib/rack/tracker/drift/drift.rb b/lib/rack/tracker/drift/drift.rb
index fb7fe34..08e3e14 100644
--- a/lib/rack/tracker/drift/drift.rb
+++ b/lib/rack/tracker/drift/drift.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::Drift < Rack::Tracker::Handler
 end
diff --git a/lib/rack/tracker/extensions.rb b/lib/rack/tracker/extensions.rb
index bfbe832..aaadadd 100644
--- a/lib/rack/tracker/extensions.rb
+++ b/lib/rack/tracker/extensions.rb
@@ -1,17 +1,20 @@
+# frozen_string_literal: true
+
 require 'ostruct'
 
 # Backport of 2.0.0 stdlib ostruct#to_h
 class OpenStruct
-  def to_h
-    @table.dup
-  end unless method_defined? :to_h
+  unless method_defined? :to_h
+    def to_h
+      @table.dup
+    end
+  end
 end
 
 class Hash
   def stringify_values
-    inject({}) do |options, (key, value)|
+    each_with_object({}) do |(key, value), options|
       options[key] = value.to_s
-      options
     end
   end
 
@@ -20,13 +23,13 @@ def compact
   end
 
   def deep_merge!(other_hash, &block)
-    other_hash.each_pair do |k,v|
+    other_hash.each_pair do |k, v|
       tv = self[k]
-      if tv.is_a?(Hash) && v.is_a?(Hash)
-        self[k] = tv.deep_merge(v, &block)
-      else
-        self[k] = block && tv ? block.call(k, tv, v) : v
-      end
+      self[k] = if tv.is_a?(Hash) && v.is_a?(Hash)
+                  tv.deep_merge(v, &block)
+                else
+                  block && tv ? block.call(k, tv, v) : v
+                end
     end
     self
   end
@@ -35,30 +38,36 @@ def deep_merge!(other_hash, &block)
   # Destructively convert all keys by using the block operation.
   # This includes the keys from the root hash and from all
   # nested hashes.
-  def deep_transform_keys!(&block)
-    _deep_transform_keys_in_object!(self, &block)
-  end unless method_defined? :deep_transform_keys!
+  unless method_defined? :deep_transform_keys!
+    def deep_transform_keys!(&block)
+      _deep_transform_keys_in_object!(self, &block)
+    end
+  end
 
-  def _deep_transform_keys_in_object!(object, &block)
-    case object
-    when Hash
-      object.keys.each do |key|
-        value = object.delete(key)
-        object[yield(key)] = _deep_transform_keys_in_object!(value, &block)
+  unless method_defined? :_deep_transform_keys_in_object!
+    def _deep_transform_keys_in_object!(object, &block)
+      case object
+      when Hash
+        object.keys.each do |key|
+          value = object.delete(key)
+          object[yield(key)] = _deep_transform_keys_in_object!(value, &block)
+        end
+        object
+      when Array
+        object.map! { |e| _deep_transform_keys_in_object!(e, &block) }
+      else
+        object
       end
-      object
-    when Array
-      object.map! {|e| _deep_transform_keys_in_object!(e, &block)}
-    else
-      object
     end
-  end unless method_defined? :_deep_transform_keys_in_object!
+  end
 
   # NOTE Back ported from Rails 4 to 3
   # Destructively convert all keys to strings.
   # This includes the keys from the root hash and from all
   # nested hashes.
-  def deep_stringify_keys!
-    deep_transform_keys!{ |key| key.to_s }
-  end unless method_defined? :deep_stringify_keys!
+  unless method_defined? :deep_stringify_keys!
+    def deep_stringify_keys!
+      deep_transform_keys!(&:to_s)
+    end
+  end
 end
diff --git a/lib/rack/tracker/facebook/facebook.rb b/lib/rack/tracker/facebook/facebook.rb
index 67a9311..9919e5c 100644
--- a/lib/rack/tracker/facebook/facebook.rb
+++ b/lib/rack/tracker/facebook/facebook.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::Facebook < Rack::Tracker::Handler
   class Event < OpenStruct
     def write
-      ['track', self.id, to_h.except(:id).compact].to_json
+      ['track', id, to_h.except(:id).compact].to_json
     end
   end
 
@@ -10,5 +12,4 @@ def write
   def self.track(name, *event)
     { name.to_s => [event.last.merge('class_name' => 'Event')] }
   end
-
 end
diff --git a/lib/rack/tracker/facebook_pixel/facebook_pixel.rb b/lib/rack/tracker/facebook_pixel/facebook_pixel.rb
index f6015dd..b182c86 100644
--- a/lib/rack/tracker/facebook_pixel/facebook_pixel.rb
+++ b/lib/rack/tracker/facebook_pixel/facebook_pixel.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::FacebookPixel < Rack::Tracker::Handler
   self.position = :body
   self.allowed_tracker_options = [:id]
diff --git a/lib/rack/tracker/go_squared/go_squared.rb b/lib/rack/tracker/go_squared/go_squared.rb
index 7885d0a..f387195 100644
--- a/lib/rack/tracker/go_squared/go_squared.rb
+++ b/lib/rack/tracker/go_squared/go_squared.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::GoSquared < Rack::Tracker::Handler
   class VisitorName < OpenStruct
     def write
-      ['set', 'visitorName', self.name].to_json.gsub(/\[|\]/, '')
+      ['set', 'visitorName', name].to_json.gsub(/\[|\]/, '')
     end
   end
 
@@ -20,10 +22,10 @@ def trackers
   end
 
   def visitor_name
-    events.select{|e| e.kind_of?(VisitorName) }.first
+    events.select { |e| e.is_a?(VisitorName) }.first
   end
 
   def visitor_info
-    events.select{|e| e.kind_of?(VisitorInfo) }.first
+    events.select { |e| e.is_a?(VisitorInfo) }.first
   end
 end
diff --git a/lib/rack/tracker/google_adwords_conversion/google_adwords_conversion.rb b/lib/rack/tracker/google_adwords_conversion/google_adwords_conversion.rb
index ecdf652..f765ffc 100644
--- a/lib/rack/tracker/google_adwords_conversion/google_adwords_conversion.rb
+++ b/lib/rack/tracker/google_adwords_conversion/google_adwords_conversion.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::GoogleAdwordsConversion < Rack::Tracker::Handler
   class Conversion < OpenStruct
   end
diff --git a/lib/rack/tracker/google_analytics/google_analytics.rb b/lib/rack/tracker/google_analytics/google_analytics.rb
index f33663b..760142f 100644
--- a/lib/rack/tracker/google_analytics/google_analytics.rb
+++ b/lib/rack/tracker/google_analytics/google_analytics.rb
@@ -1,9 +1,10 @@
-class Rack::Tracker::GoogleAnalytics < Rack::Tracker::Handler
+# frozen_string_literal: true
 
-  self.allowed_tracker_options = [:cookie_domain, :user_id]
+class Rack::Tracker::GoogleAnalytics < Rack::Tracker::Handler
+  self.allowed_tracker_options = %i[cookie_domain user_id]
 
   def initialize(env, options = {})
-    options[:explicit_pageview] = true if !options.has_key?(:explicit_pageview)
+    options[:explicit_pageview] = true unless options.key?(:explicit_pageview)
     super(env, options)
   end
 
@@ -18,22 +19,22 @@ def write
     end
 
     def event
-      { hitType: self.type }.merge(attributes.stringify_values).compact
+      { hitType: type }.merge(attributes.stringify_values).compact
     end
 
     def attributes
-      Hash[to_h.slice(:category, :action, :label, :value).map { |k,v| [self.type.to_s + k.to_s.capitalize, v] }]
+      Hash[to_h.slice(:category, :action, :label, :value).map { |k, v| [type.to_s + k.to_s.capitalize, v] }]
     end
   end
 
   class EnhancedEcommerce < OpenStruct
     def write
-      hash = self.to_h
+      hash = to_h
       label = hash[:label]
       attributes = hash.except(:label, :type).compact.stringify_values
 
       [
-        "ec:#{self.type}",
+        "ec:#{type}",
         label,
         attributes.empty? ? nil : attributes
       ].compact.to_json.gsub(/\[|\]/, '')
@@ -42,10 +43,10 @@ def write
 
   class Ecommerce < OpenStruct
     def write
-      attributes = self.to_h.except(:type).compact.stringify_values
+      attributes = to_h.except(:type).compact.stringify_values
 
       [
-        "ecommerce:#{self.type}",
+        "ecommerce:#{type}",
         attributes
       ].to_json.gsub(/\[|\]/, '')
     end
@@ -54,7 +55,7 @@ def write
   class Parameter < OpenStruct
     include Rack::Tracker::JavaScriptHelper
     def write
-      ['set', self.to_h.to_a].flatten.map { |v| %Q{'#{j(v)}'} }.join ', '
+      ['set', to_h.to_a].flatten.map { |v| %('#{j(v)}') }.join ', '
     end
   end
 
@@ -63,11 +64,11 @@ def tracker
   end
 
   def ecommerce_events
-    events.select {|e| e.kind_of?(Ecommerce) }
+    events.select { |e| e.is_a?(Ecommerce) }
   end
 
   def enhanced_ecommerce_events
-    events.select {|e| e.kind_of?(EnhancedEcommerce) }
+    events.select { |e| e.is_a?(EnhancedEcommerce) }
   end
 
   def pageview_url_script
diff --git a/lib/rack/tracker/google_global/google_global.rb b/lib/rack/tracker/google_global/google_global.rb
index 5ccb817..929559d 100644
--- a/lib/rack/tracker/google_global/google_global.rb
+++ b/lib/rack/tracker/google_global/google_global.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::GoogleGlobal < Rack::Tracker::Handler
-  self.allowed_tracker_options = [:cookie_domain, :user_id,
-    :link_attribution, :allow_display_features, :anonymize_ip,
-    :custom_map, :optimize_id]
+  self.allowed_tracker_options = %i[cookie_domain user_id
+                                    link_attribution allow_display_features anonymize_ip
+                                    custom_map optimize_id]
 
   class Page < OpenStruct
     def params
@@ -10,8 +12,8 @@ def params
   end
 
   class Event < OpenStruct
-    PREFIXED_PARAMS = %i[category label]
-    SKIP_PARAMS  = %i[action]
+    PREFIXED_PARAMS = %i[category label].freeze
+    SKIP_PARAMS = %i[action].freeze
 
     def params
       Hash[to_h.except(*SKIP_PARAMS).map { |key, value| [param_key(key), value] }]
@@ -59,8 +61,8 @@ def call_tracker(tracker)
   def invalid_tracker?(tracker)
     if tracker[:id].to_s.strip == ''
       $stdout.puts <<~WARN
-      WARNING: One of the trackers specified for Rack::Tracker handler 'google_global' is empty.
-               Trackers: #{options[:trackers]}
+        WARNING: One of the trackers specified for Rack::Tracker handler 'google_global' is empty.
+                 Trackers: #{options[:trackers]}
       WARN
 
       true
diff --git a/lib/rack/tracker/google_tag_manager/google_tag_manager.rb b/lib/rack/tracker/google_tag_manager/google_tag_manager.rb
index 2db9d2b..77f53f4 100644
--- a/lib/rack/tracker/google_tag_manager/google_tag_manager.rb
+++ b/lib/rack/tracker/google_tag_manager/google_tag_manager.rb
@@ -1,5 +1,6 @@
-class Rack::Tracker::GoogleTagManager < Rack::Tracker::Handler
+# frozen_string_literal: true
 
+class Rack::Tracker::GoogleTagManager < Rack::Tracker::Handler
   class Push < OpenStruct
     def write
       to_h.to_json
@@ -10,11 +11,11 @@ def inject(response)
     # Sub! is enough, in well formed html there's only one head or body tag.
     # Block syntax need to be used, otherwise backslashes in input will mess the output.
     # @see http://stackoverflow.com/a/4149087/518204 and https://github.com/railslove/rack-tracker/issues/50
-    response.sub! %r{<head.*>} do |m|
-      m.to_s << self.render_head
+    response.sub! /<head.*>/ do |m|
+      m.to_s << render_head
     end
-    response.sub! %r{<body.*?>} do |m|
-      m.to_s << self.render_body
+    response.sub! /<body.*?>/ do |m|
+      m.to_s << render_body
     end
     response
   end
@@ -24,10 +25,10 @@ def container
   end
 
   def render_head
-    Tilt.new( File.join( File.dirname(__FILE__), 'template', 'google_tag_manager_head.erb') ).render(self)
+    Tilt.new(File.join(File.dirname(__FILE__), 'template', 'google_tag_manager_head.erb')).render(self)
   end
 
   def render_body
-    Tilt.new( File.join( File.dirname(__FILE__), 'template', 'google_tag_manager_body.erb') ).render(self)
+    Tilt.new(File.join(File.dirname(__FILE__), 'template', 'google_tag_manager_body.erb')).render(self)
   end
 end
diff --git a/lib/rack/tracker/handler.rb b/lib/rack/tracker/handler.rb
index 2e31195..c9c5397 100644
--- a/lib/rack/tracker/handler.rb
+++ b/lib/rack/tracker/handler.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::Handler
   class << self
     def process_track(env, method_name, *args, &block)
@@ -25,7 +27,7 @@ def track(name, *event)
   def initialize(env, options = {})
     self.env = env
     self.options  = options
-    self.position = options[:position] if options.has_key?(:position)
+    self.position = options[:position] if options.key?(:position)
   end
 
   def events
@@ -34,20 +36,19 @@ def events
   end
 
   def render
-    Tilt.new(File.join(File.dirname(__FILE__), handler_name, 'template', "#{handler_name}.erb") ).render(self)
+    Tilt.new(File.join(File.dirname(__FILE__), handler_name, 'template', "#{handler_name}.erb")).render(self)
   end
 
   def inject(response)
     # default to not inject this tracker if the DNT HTTP header is set
     # if the DO_NOT_RESPECT_DNT_HEADER config is set the DNT header is ignored :( - please do respect the DNT header!
-    if self.dnt_header_opt_out? && !self.options.has_key?(:DO_NOT_RESPECT_DNT_HEADER)
-      return response
-    end
+    return response if dnt_header_opt_out? && !options.key?(:DO_NOT_RESPECT_DNT_HEADER)
+
     # Sub! is enough, in well formed html there's only one head or body tag.
     # Block syntax need to be used, otherwise backslashes in input will mess the output.
     # @see http://stackoverflow.com/a/4149087/518204 and https://github.com/railslove/rack-tracker/issues/50
-    response.sub! %r{</#{self.position}>} do |m|
-      self.render << m.to_s
+    response.sub! %r{</#{position}>} do |m|
+      render << m.to_s
     end
     response
   end
@@ -55,9 +56,9 @@ def inject(response)
   def write_event(event)
     event.deep_stringify_keys! # for consistent hash access use strings (keys from the session are always strings anyway)
     if env.key?('tracker')
-      self.env['tracker'].deep_merge!(event) { |key, old, new| Array.wrap(old) + Array.wrap(new) }
+      env['tracker'].deep_merge!(event) { |_key, old, new| Array.wrap(old) + Array.wrap(new) }
     else
-      self.env['tracker'] = event
+      env['tracker'] = event
     end
   end
 
@@ -69,16 +70,14 @@ def tracker_options
     @_tracker_options ||= {}.tap do |tracker_options|
       options.slice(*allowed_tracker_options).each do |key, value|
         option_value = value.respond_to?(:call) ? value.call(env) : value
-        unless option_value.nil? 
-          tracker_options[tracker_option_key(key)] = tracker_option_value(option_value)
-        end
+        tracker_options[tracker_option_key(key)] = tracker_option_value(option_value) unless option_value.nil?
       end
     end
   end
 
   # the request has set the DO NOT TRACK (DNT) and has opted to get not tracked (DNT=1)
   def dnt_header_opt_out?
-    self.env['HTTP_DNT'] && self.env['HTTP_DNT'].to_s == '1'
+    env['HTTP_DNT'] && env['HTTP_DNT'].to_s == '1'
   end
 
   private
diff --git a/lib/rack/tracker/handler_delegator.rb b/lib/rack/tracker/handler_delegator.rb
index f968fa9..59f4503 100644
--- a/lib/rack/tracker/handler_delegator.rb
+++ b/lib/rack/tracker/handler_delegator.rb
@@ -1,8 +1,8 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::HandlerDelegator
   class << self
-    def handler(method_name)
-      new.handler(method_name)
-    end
+    delegate :handler, to: :new
   end
 
   attr_accessor :env
@@ -24,15 +24,13 @@ def respond_to?(method_name, include_private = false)
   end
 
   def handler(method_name)
-    return method_name if method_name.kind_of?(Class)
+    return method_name if method_name.is_a?(Class)
 
     _handler = method_name.to_s.camelize
     ["Rack::Tracker::#{_handler}", _handler].detect do |const|
-      begin
-        return const.constantize
-      rescue NameError
-        false
-      end
+      return const.constantize
+    rescue NameError
+      false
     end
 
     raise ArgumentError, "No such Handler: #{_handler}"
diff --git a/lib/rack/tracker/heap/heap.rb b/lib/rack/tracker/heap/heap.rb
index dac9efb..6b0a2f7 100644
--- a/lib/rack/tracker/heap/heap.rb
+++ b/lib/rack/tracker/heap/heap.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::Heap < Rack::Tracker::Handler
 end
diff --git a/lib/rack/tracker/hotjar/hotjar.rb b/lib/rack/tracker/hotjar/hotjar.rb
index 482e5d3..8635587 100644
--- a/lib/rack/tracker/hotjar/hotjar.rb
+++ b/lib/rack/tracker/hotjar/hotjar.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::Hotjar < Rack::Tracker::Handler
 end
diff --git a/lib/rack/tracker/hubspot/hubspot.rb b/lib/rack/tracker/hubspot/hubspot.rb
index 162b07c..733c297 100644
--- a/lib/rack/tracker/hubspot/hubspot.rb
+++ b/lib/rack/tracker/hubspot/hubspot.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::Hubspot < Rack::Tracker::Handler
 end
diff --git a/lib/rack/tracker/javascript_helper.rb b/lib/rack/tracker/javascript_helper.rb
index 02ccdfb..9be92fe 100644
--- a/lib/rack/tracker/javascript_helper.rb
+++ b/lib/rack/tracker/javascript_helper.rb
@@ -1,17 +1,18 @@
+# frozen_string_literal: true
+
 # This module is extracted from Rails to provide reliable javascript escaping.
 #
 # @see https://github.com/rails/rails/blob/master/actionview/lib/action_view/helpers/javascript_helper.rb
 module Rack::Tracker::JavaScriptHelper
-
   JS_ESCAPE_MAP = {
-      '\\' => '\\\\',
-      '</' => '<\/',
-      "\r\n" => '\n',
-      "\n" => '\n',
-      "\r" => '\n',
-      '"' => '\\"',
-      "'" => "\\'"
-  }
+    '\\' => '\\\\',
+    '</' => '<\/',
+    "\r\n" => '\n',
+    "\n" => '\n',
+    "\r" => '\n',
+    '"' => '\\"',
+    "'" => "\\'"
+  }.freeze
 
   JS_ESCAPE_MAP["\342\200\250".force_encoding(Encoding::UTF_8).encode!] = '&#x2028;'
   JS_ESCAPE_MAP["\342\200\251".force_encoding(Encoding::UTF_8).encode!] = '&#x2029;'
@@ -24,11 +25,11 @@ module Rack::Tracker::JavaScriptHelper
   #   $('some_element').replaceWith('<%=j render 'some/element_template' %>');
   def escape_javascript(javascript)
     if javascript
-      javascript.to_s.gsub(/(\\|<\/|\r\n|\342\200\250|\342\200\251|[\n\r"'])/u) { |match| JS_ESCAPE_MAP[match] }
+      javascript.to_s.gsub(%r{(\\|</|\r\n|\342\200\250|\342\200\251|[\n\r"'])}u) { |match| JS_ESCAPE_MAP[match] }
     else
       ''
     end
   end
 
-  alias_method :j, :escape_javascript
+  alias j escape_javascript
 end
diff --git a/lib/rack/tracker/railtie.rb b/lib/rack/tracker/railtie.rb
index 965cb73..9536b24 100644
--- a/lib/rack/tracker/railtie.rb
+++ b/lib/rack/tracker/railtie.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 module Rack
   class Tracker
     class Railtie < ::Rails::Railtie
-      initializer "rack-tracker.configure_controller" do |app|
+      initializer 'rack-tracker.configure_controller' do |_app|
         ActiveSupport.on_load :action_controller do
           include Rack::Tracker::Controller
         end
diff --git a/lib/rack/tracker/version.rb b/lib/rack/tracker/version.rb
index fb24a29..ec706db 100644
--- a/lib/rack/tracker/version.rb
+++ b/lib/rack/tracker/version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Rack
   class Tracker
     VERSION = '1.12.0'
diff --git a/lib/rack/tracker/vwo/vwo.rb b/lib/rack/tracker/vwo/vwo.rb
index c7fdfa3..71be6a6 100644
--- a/lib/rack/tracker/vwo/vwo.rb
+++ b/lib/rack/tracker/vwo/vwo.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class Rack::Tracker::Vwo < Rack::Tracker::Handler
 end
diff --git a/lib/rack/tracker/zanox/zanox.rb b/lib/rack/tracker/zanox/zanox.rb
index a674b6f..b72709a 100644
--- a/lib/rack/tracker/zanox/zanox.rb
+++ b/lib/rack/tracker/zanox/zanox.rb
@@ -1,10 +1,11 @@
-class Rack::Tracker::Zanox < Rack::Tracker::Handler
+# frozen_string_literal: true
 
+class Rack::Tracker::Zanox < Rack::Tracker::Handler
   # name of the handler
   # everything after is passed as options
   class Mastertag < OpenStruct
     def write
-      to_h.except(:id).map do |k,v|
+      to_h.except(:id).map do |k, v|
         "var zx_#{k} = #{v.to_json};"
       end.join("\n")
     end
@@ -13,7 +14,7 @@ def write
   class Lead < OpenStruct
     # Example: OrderID=[[DEFC-4321]]&CurrencySymbol=[[EUR]]&TotalPrice=[[23.40]]
     def write
-      to_h.map do |k,v|
+      to_h.map do |k, v|
         "#{k.to_s.camelize}=[[#{v}]]"
       end.join('&')
     end
@@ -26,14 +27,14 @@ def write
   def mastertag
     # First event should be stronger, e.g. one signs up and gets redirected to homepage
     # "sign up" should be tracked instead of "view homepage"
-    events.select{ |event| event.class.to_s.demodulize == 'Mastertag' }.first
+    events.select { |event| event.class.to_s.demodulize == 'Mastertag' }.first
   end
 
   def lead_events
-    events.select{ |event| event.class.to_s.demodulize == 'Lead' }
+    events.select { |event| event.class.to_s.demodulize == 'Lead' }
   end
 
   def sale_events
-    events.select{ |event| event.class.to_s.demodulize == 'Sale' }
+    events.select { |event| event.class.to_s.demodulize == 'Sale' }
   end
 end
diff --git a/rack-tracker.gemspec b/rack-tracker.gemspec
index d5fa3d2..dd92768 100644
--- a/rack-tracker.gemspec
+++ b/rack-tracker.gemspec
@@ -1,35 +1,36 @@
-# coding: utf-8
-lib = File.expand_path('../lib', __FILE__)
+# frozen_string_literal: true
+
+lib = File.expand_path('lib', __dir__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'rack/tracker/version'
 
 Gem::Specification.new do |spec|
-  spec.name          = "rack-tracker"
+  spec.name          = 'rack-tracker'
   spec.version       = Rack::Tracker::VERSION
-  spec.authors       = ["Lars Brillert", "Marco Schaden"]
-  spec.email         = ["lars@railslove.com", "marco@railslove.com"]
-  spec.summary       = %q{Tracking made easy}
-  spec.description   = %q{Don’t fool around with adding tracking partials to your app and concentrate on the things that matter.}
-  spec.homepage      = "https://github.com/railslove/rack-tracker"
-  spec.license       = "MIT"
+  spec.authors       = ['Lars Brillert', 'Marco Schaden']
+  spec.email         = ['lars@railslove.com', 'marco@railslove.com']
+  spec.summary       = 'Tracking made easy'
+  spec.description   = 'Don’t fool around with adding tracking partials to your app and concentrate on the things that matter.'
+  spec.homepage      = 'https://github.com/railslove/rack-tracker'
+  spec.license       = 'MIT'
 
   spec.files         = `git ls-files -z`.split("\x0")
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
-  spec.require_paths = ["lib"]
+  spec.require_paths = ['lib']
 
-  spec.add_dependency "rack", ">= 1.4"
-  spec.add_dependency "tilt", ">= 1.4"
   spec.add_dependency 'activesupport', '>= 3.0'
+  spec.add_dependency 'rack', '>= 1.4'
+  spec.add_dependency 'tilt', '>= 1.4'
 
   spec.add_development_dependency 'actionpack', '>= 3.0'
-  spec.add_development_dependency "bundler", ">= 1.16"
-  spec.add_development_dependency "rake"
-  spec.add_development_dependency "rspec", "~> 3.2"
-  spec.add_development_dependency "capybara", "~> 2.4"
-  spec.add_development_dependency "pry"
-  if RUBY_VERSION < "2.0"
-    spec.add_development_dependency "mime-types", "< 3.0"
-    spec.add_development_dependency "addressable", "< 2.5"
+  spec.add_development_dependency 'bundler', '>= 1.16'
+  spec.add_development_dependency 'capybara', '~> 2.4'
+  spec.add_development_dependency 'pry'
+  spec.add_development_dependency 'rake'
+  spec.add_development_dependency 'rspec', '~> 3.2'
+  if RUBY_VERSION < '2.0'
+    spec.add_development_dependency 'addressable', '< 2.5'
+    spec.add_development_dependency 'mime-types', '< 3.0'
   end
 end
diff --git a/spec/benchmark/tracker_injection_benchmark.rb b/spec/benchmark/tracker_injection_benchmark.rb
index 2874eb1..f986b5e 100644
--- a/spec/benchmark/tracker_injection_benchmark.rb
+++ b/spec/benchmark/tracker_injection_benchmark.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 require 'benchmark'
 
diff --git a/spec/handler/bing_spec.rb b/spec/handler/bing_spec.rb
index 843752a..e17a758 100644
--- a/spec/handler/bing_spec.rb
+++ b/spec/handler/bing_spec.rb
@@ -1,53 +1,53 @@
-RSpec.describe Rack::Tracker::Bing do
+# frozen_string_literal: true
 
+RSpec.describe Rack::Tracker::Bing do
   it 'will be placed in the body' do
     expect(described_class.position).to eq(:body)
   end
 
-  describe "with events" do
+  describe 'with events' do
     subject { described_class.new(env, tracker: 'somebody').render }
 
-    describe "default" do
+    describe 'default' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'bing' => [
             { 'class_name' => 'Conversion', 'category' => 'Users', 'action' => 'Login', 'label' => 'Standard', 'value' => 10 }
           ]
-        }}
+        } }
       end
 
-      it "will show event initialiser" do
-        expect(subject).to include "window.uetq = window.uetq || [];"
+      it 'will show event initialiser' do
+        expect(subject).to include 'window.uetq = window.uetq || [];'
       end
 
-      it "will show events" do
+      it 'will show events' do
         expect(subject).to include "window.uetq.push({ 'ec': 'Users', 'ea': 'Login', 'el': 'Standard', 'ev': 10 });"
       end
     end
   end
 
-  describe "with multiple events" do
+  describe 'with multiple events' do
     subject { described_class.new(env, tracker: 'somebody').render }
 
-    describe "default" do
+    describe 'default' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'bing' => [
             { 'class_name' => 'Conversion', 'category' => 'Users', 'action' => 'Login', 'label' => 'Standard', 'value' => 10 },
             { 'class_name' => 'Conversion', 'category' => 'Users', 'action' => 'Logout', 'label' => 'Standard', 'value' => 5 }
           ]
-        }}
+        } }
       end
 
-      it "will show event initialiser" do
-        expect(subject).to include "window.uetq = window.uetq || [];"
+      it 'will show event initialiser' do
+        expect(subject).to include 'window.uetq = window.uetq || [];'
       end
 
-      it "will show events" do
+      it 'will show events' do
         expect(subject).to include "window.uetq.push({ 'ec': 'Users', 'ea': 'Login', 'el': 'Standard', 'ev': 10 });"
         expect(subject).to include "window.uetq.push({ 'ec': 'Users', 'ea': 'Logout', 'el': 'Standard', 'ev': 5 });"
       end
     end
   end
-
-end
\ No newline at end of file
+end
diff --git a/spec/handler/criteo_spec.rb b/spec/handler/criteo_spec.rb
index 8feded3..d12efde 100644
--- a/spec/handler/criteo_spec.rb
+++ b/spec/handler/criteo_spec.rb
@@ -1,11 +1,11 @@
-RSpec.describe Rack::Tracker::Criteo do
+# frozen_string_literal: true
 
+RSpec.describe Rack::Tracker::Criteo do
   describe Rack::Tracker::Criteo::Event do
-
-    subject { described_class.new(event: "viewItem", item: 'P001') }
+    subject { described_class.new(event: 'viewItem', item: 'P001') }
 
     describe '#write' do
-      specify { expect(subject.write).to eq("{\"event\":\"viewItem\",\"item\":\"P001\"}") }
+      specify { expect(subject.write).to eq('{"event":"viewItem","item":"P001"}') }
     end
   end
 
@@ -20,20 +20,20 @@ def env
 
   describe '#render' do
     context 'with events' do
-      let(:env) {
+      let(:env) do
         {
           'tracker' => {
-          'criteo' =>
-            [
-              {
-                'event' => 'viewItem',
-                'item' => 'P001',
-                'class_name' => 'Event'
-              }
-            ]
+            'criteo' =>
+                        [
+                          {
+                            'event' => 'viewItem',
+                            'item' => 'P001',
+                            'class_name' => 'Event'
+                          }
+                        ]
           }
         }
-      }
+      end
 
       subject { described_class.new(env).render }
 
@@ -43,18 +43,18 @@ def env
     end
 
     context 'without events' do
-      let(:env) {
+      let(:env) do
         {
           'tracker' => {
             'criteo' => []
           }
         }
-      }
+      end
 
-      subject { described_class.new(env, { user_id: ->(env){ '123' } }).render }
+      subject { described_class.new(env, { user_id: ->(_env) { '123' } }).render }
 
-      it 'should render nothing' do
-        expect(subject).to eql ""
+      it 'renders nothing' do
+        expect(subject).to eql ''
       end
     end
   end
@@ -65,7 +65,7 @@ def env
     context 'nil value' do
       let(:options) { { set_account: nil } }
 
-      it 'should ignore option' do
+      it 'ignores option' do
         expect(subject.tracker_events).to match_array []
       end
     end
@@ -73,7 +73,7 @@ def env
     context 'static string value' do
       let(:options) { { set_account: '1234' } }
 
-      it 'should set the value' do
+      it 'sets the value' do
         expect(subject.tracker_events).to match_array [
           Rack::Tracker::Criteo::Event.new(event: 'setAccount', account: '1234')
         ]
@@ -83,7 +83,7 @@ def env
     context 'static integer value' do
       let(:options) { { set_customer_id: 1234 } }
 
-      it 'should set the value as string' do
+      it 'sets the value as string' do
         expect(subject.tracker_events).to match_array [
           Rack::Tracker::Criteo::Event.new(event: 'setCustomerId', id: '1234')
         ]
@@ -91,19 +91,19 @@ def env
     end
 
     context 'unsupported option' do
-      let(:options) { { unsupported: "option" } }
+      let(:options) { { unsupported: 'option' } }
 
       subject { described_class.new(env, options) }
 
-      it 'should ignore the option' do
+      it 'ignores the option' do
         expect(subject.tracker_events).to match_array []
       end
     end
 
     context 'proc returning value' do
-      let(:options) { { set_site_type: ->(env){ 'm' } } }
+      let(:options) { { set_site_type: ->(_env) { 'm' } } }
 
-      it 'should set the value' do
+      it 'sets the value' do
         expect(subject.tracker_events).to match_array [
           Rack::Tracker::Criteo::Event.new(event: 'setSiteType', type: 'm')
         ]
@@ -111,12 +111,11 @@ def env
     end
 
     context 'proc returning nil' do
-      let(:options) { { set_account: ->(env){ nil } } }
+      let(:options) { { set_account: ->(_env) { nil } } }
 
-      it 'should ignore the option' do
+      it 'ignores the option' do
         expect(subject.tracker_events).to match_array []
       end
     end
   end
-
-end
\ No newline at end of file
+end
diff --git a/spec/handler/drift_spec.rb b/spec/handler/drift_spec.rb
index 5f96374..399a225 100644
--- a/spec/handler/drift_spec.rb
+++ b/spec/handler/drift_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 RSpec.describe Rack::Tracker::Drift do
   def env
     { foo: 'bar' }
diff --git a/spec/handler/facebook_pixel_spec.rb b/spec/handler/facebook_pixel_spec.rb
index 9716529..47709f4 100644
--- a/spec/handler/facebook_pixel_spec.rb
+++ b/spec/handler/facebook_pixel_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 RSpec.describe Rack::Tracker::FacebookPixel do
   def env
     { 'PIXEL_ID' => 'DYNAMIC_PIXEL_ID' }
@@ -12,7 +14,7 @@ def env
     subject { described_class.new(env, id: 'PIXEL_ID').render }
 
     it 'will push the tracking events to the queue' do
-      expect(subject).to match(%r{fbq\('init', 'PIXEL_ID'\)})
+      expect(subject).to match(/fbq\('init', 'PIXEL_ID'\)/)
     end
 
     it 'will add the noscript fallback' do
@@ -21,10 +23,10 @@ def env
   end
 
   describe 'with dynamic id' do
-    subject { described_class.new(env, id: lambda { |env| env['PIXEL_ID'] }).render }
+    subject { described_class.new(env, id: ->(env) { env['PIXEL_ID'] }).render }
 
     it 'will push the tracking events to the queue' do
-      expect(subject).to match(%r{fbq\('init', 'DYNAMIC_PIXEL_ID'\)})
+      expect(subject).to match(/fbq\('init', 'DYNAMIC_PIXEL_ID'\)/)
     end
 
     it 'will add the noscript fallback' do
@@ -36,34 +38,34 @@ def env
     def env
       {
         'tracker' => {
-        'facebook_pixel' =>
-          [
-            {
-              'type' => 'Purchase',
-              'class_name' => 'Track',
-              'options' =>
-                {
-                  'value' => '23',
-                  'currency' => 'EUR'
-                }
-            },{
-              'type' => 'FrequentShopper',
-              'class_name' => 'TrackCustom',
-              'options' =>
-                {
-                  'purchases' => 8,
-                  'category' => 'Sport'
-                }
-            }
-          ]
+          'facebook_pixel' =>
+                              [
+                                {
+                                  'type' => 'Purchase',
+                                  'class_name' => 'Track',
+                                  'options' =>
+                                                  {
+                                                    'value' => '23',
+                                                    'currency' => 'EUR'
+                                                  }
+                                }, {
+                                  'type' => 'FrequentShopper',
+                                  'class_name' => 'TrackCustom',
+                                  'options' =>
+                                                  {
+                                                    'purchases' => 8,
+                                                    'category' => 'Sport'
+                                                  }
+                                }
+                              ]
         }
       }
     end
     subject { described_class.new(env).render }
 
     it 'will push the tracking events to the queue' do
-      expect(subject).to match(%r{"track", "Purchase", \{"value":"23","currency":"EUR"\}})
-      expect(subject).to match(%r{"trackCustom", "FrequentShopper", \{"purchases":8,"category":"Sport"\}})
+      expect(subject).to match(/"track", "Purchase", \{"value":"23","currency":"EUR"\}/)
+      expect(subject).to match(/"trackCustom", "FrequentShopper", \{"purchases":8,"category":"Sport"\}/)
     end
 
     it 'will add the noscript fallback' do
diff --git a/spec/handler/facebook_spec.rb b/spec/handler/facebook_spec.rb
index 6a24738..456cd63 100644
--- a/spec/handler/facebook_spec.rb
+++ b/spec/handler/facebook_spec.rb
@@ -1,10 +1,11 @@
+# frozen_string_literal: true
+
 RSpec.describe Rack::Tracker::Facebook do
   describe Rack::Tracker::Facebook::Event do
-
-    subject { described_class.new({id: 'id', foo: 'bar'}) }
+    subject { described_class.new({ id: 'id', foo: 'bar' }) }
 
     describe '#write' do
-      specify { expect(subject.write).to eq(['track', 'id', {foo: 'bar'}].to_json) }
+      specify { expect(subject.write).to eq(['track', 'id', { foo: 'bar' }].to_json) }
     end
   end
 
@@ -21,8 +22,8 @@ def env
     subject { described_class.new(env, custom_audience: 'custom_audience_id').render }
 
     it 'will push the tracking events to the queue' do
-      expect(subject).to match(%r{window._fbq.push\(\["addPixelId", "custom_audience_id"\]\)})
-      expect(subject).to match(%r{window._fbq.push\(\["track", "PixelInitialized", \{\}\]\)})
+      expect(subject).to match(/window._fbq.push\(\["addPixelId", "custom_audience_id"\]\)/)
+      expect(subject).to match(/window._fbq.push\(\["track", "PixelInitialized", \{\}\]\)/)
     end
 
     it 'will add the noscript fallback' do
@@ -34,22 +35,22 @@ def env
     def env
       {
         'tracker' => {
-        'facebook' =>
-          [
-            {
-              'id' => '123456789',
-              'value' => '23',
-              'currency' => 'EUR',
-              'class_name' => 'Event'
-            }
-          ]
+          'facebook' =>
+                        [
+                          {
+                            'id' => '123456789',
+                            'value' => '23',
+                            'currency' => 'EUR',
+                            'class_name' => 'Event'
+                          }
+                        ]
         }
       }
     end
     subject { described_class.new(env).render }
 
     it 'will push the tracking events to the queue' do
-      expect(subject).to match(%r{\["track","123456789",\{"value":"23","currency":"EUR"\}\]})
+      expect(subject).to match(/\["track","123456789",\{"value":"23","currency":"EUR"\}\]/)
     end
 
     it 'will add the noscript fallback' do
diff --git a/spec/handler/go_squared_spec.rb b/spec/handler/go_squared_spec.rb
index 4d15bab..7898074 100644
--- a/spec/handler/go_squared_spec.rb
+++ b/spec/handler/go_squared_spec.rb
@@ -1,7 +1,8 @@
-RSpec.describe Rack::Tracker::GoSquared do
+# frozen_string_literal: true
 
+RSpec.describe Rack::Tracker::GoSquared do
   def env
-    {misc: 'foobar'}
+    { misc: 'foobar' }
   end
 
   it 'will be placed in the head' do
@@ -9,38 +10,37 @@ def env
     expect(described_class.new(env).position).to eq(:head)
   end
 
-  describe "with events" do
-    describe "visitor name" do
+  describe 'with events' do
+    describe 'visitor name' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'go_squared' => [
             { 'class_name' => 'VisitorName', 'name' => 'John Doe' }
           ]
-        }}
+        } }
       end
 
       subject { described_class.new(env, tracker: '12345').render }
 
-      it "will show the right name" do
-        expect(subject).to match(%r{_gs\(\"set\",\"visitorName\",\"John Doe\"\)})
+      it 'will show the right name' do
+        expect(subject).to match(/_gs\(\"set\",\"visitorName\",\"John Doe\"\)/)
       end
     end
 
-    describe "visitor details" do
+    describe 'visitor details' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'go_squared' => [
             { 'class_name' => 'VisitorInfo', 'age' => 35, 'favorite_food' => 'pizza' }
           ]
-        }}
+        } }
       end
 
       subject { described_class.new(env, tracker: '12345').render }
 
-      it "will show the right properties" do
-        expect(subject).to match(%r{_gs\(\"set\",\"visitor\",{\"age\":35,\"favorite_food\":\"pizza\"}\)})
+      it 'will show the right properties' do
+        expect(subject).to match(/_gs\(\"set\",\"visitor\",{\"age\":35,\"favorite_food\":\"pizza\"}\)/)
       end
     end
   end
-
 end
diff --git a/spec/handler/google_adwords_conversion_spec.rb b/spec/handler/google_adwords_conversion_spec.rb
index 52536cf..26b0443 100644
--- a/spec/handler/google_adwords_conversion_spec.rb
+++ b/spec/handler/google_adwords_conversion_spec.rb
@@ -1,5 +1,6 @@
-RSpec.describe Rack::Tracker::GoogleAdwordsConversion do
+# frozen_string_literal: true
 
+RSpec.describe Rack::Tracker::GoogleAdwordsConversion do
   def env
     {
       misc: 'foobar',
@@ -13,23 +14,24 @@ def env
     expect(described_class.new(env, position: :body).position).to eq(:body)
   end
 
-  describe "with events" do
-    describe "default" do
+  describe 'with events' do
+    describe 'default' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'google_adwords_conversion' => [
-            { 'class_name' => 'Conversion', 'id' => 123456, 'language' => 'en', 'format' => '3', 'color' => 'ffffff', 'label' => 'Conversion Label' }
+            { 'class_name' => 'Conversion', 'id' => 123_456, 'language' => 'en', 'format' => '3', 'color' => 'ffffff', 'label' => 'Conversion Label' }
           ]
-        }}
+        } }
       end
 
       subject { described_class.new(env).render }
+
       it 'will show events' do
-        expect(subject).to match(%r{var google_conversion_id = 123456;})
-        expect(subject).to match(%r{var google_conversion_language = 'en';})
-        expect(subject).to match(%r{var google_conversion_format = '3';})
-        expect(subject).to match(%r{var google_conversion_color = 'ffffff';})
-        expect(subject).to match(%r{var google_conversion_label = 'Conversion Label';})
+        expect(subject).to match(/var google_conversion_id = 123456;/)
+        expect(subject).to match(/var google_conversion_language = 'en';/)
+        expect(subject).to match(/var google_conversion_format = '3';/)
+        expect(subject).to match(/var google_conversion_color = 'ffffff';/)
+        expect(subject).to match(/var google_conversion_label = 'Conversion Label';/)
         expect(subject).to match(%r{<img.*src=\"\/\/www.googleadservices.com\/pagead\/conversion\/123456\/\?label=Conversion%20Label&amp;guid=ON&amp;script=0\"/>})
       end
     end
@@ -37,11 +39,13 @@ def env
 
   describe 'with options' do
     context 'when there are no params for the handler' do
-      let(:options) { { id: 123456,
-                        language: 'en',
-                        format: '3',
-                        color: 'ffffff',
-                        label: 'Conversion Label' } }
+      let(:options) do
+        { id: 123_456,
+          language: 'en',
+          format: '3',
+          color: 'ffffff',
+          label: 'Conversion Label' }
+      end
       let(:env) do
         {
           'tracker' => {
@@ -55,12 +59,12 @@ def env
       subject { described_class.new(env, options).render }
 
       it 'will show events by using default options' do
-        expect(subject).to match(%r{var google_conversion_id = 123456;})
-        expect(subject).to match(%r{var google_conversion_language = 'en';})
-        expect(subject).to match(%r{var google_conversion_format = '3';})
-        expect(subject).to match(%r{var google_conversion_color = 'ffffff';})
-        expect(subject).to match(%r{var google_conversion_label = 'Conversion Label';})
-        expect(subject).to match(%r{var google_conversion_value = 10.0;})
+        expect(subject).to match(/var google_conversion_id = 123456;/)
+        expect(subject).to match(/var google_conversion_language = 'en';/)
+        expect(subject).to match(/var google_conversion_format = '3';/)
+        expect(subject).to match(/var google_conversion_color = 'ffffff';/)
+        expect(subject).to match(/var google_conversion_label = 'Conversion Label';/)
+        expect(subject).to match(/var google_conversion_value = 10.0;/)
         expect(subject).to match(%r{<img.*src=\"\/\/www.googleadservices.com\/pagead\/conversion\/123456\/\?label=Conversion%20Label&amp;guid=ON&amp;script=0\"/>})
       end
     end
diff --git a/spec/handler/google_analytics_spec.rb b/spec/handler/google_analytics_spec.rb
index 6951a02..447b15e 100644
--- a/spec/handler/google_analytics_spec.rb
+++ b/spec/handler/google_analytics_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 RSpec.describe Rack::Tracker::GoogleAnalytics do
   def env
     {
@@ -62,7 +64,7 @@ def env
     end
 
     context 'with an allowed option configured with a block' do
-      subject { described_class.new(env, { user_id: lambda { |env| return env[:misc] } }) }
+      subject { described_class.new(env, { user_id: ->(env) { return env[:misc] } }) }
 
       it 'returns hash with option set' do
         expect(subject.tracker_options).to eql ({ userId: 'foobar' })
@@ -70,7 +72,7 @@ def env
     end
 
     context 'with an allowed option configured with a block returning nil' do
-      subject { described_class.new(env, { user_id: lambda { |env| return env[:non_existing_key] } }) }
+      subject { described_class.new(env, { user_id: ->(env) { return env[:non_existing_key] } }) }
 
       it 'returns an empty hash' do
         expect(subject.tracker_options).to eql ({})
@@ -86,215 +88,215 @@ def env
     end
   end
 
-  describe "with events" do
+  describe 'with events' do
     subject { described_class.new(env, tracker: 'somebody').render }
 
-    describe "default" do
+    describe 'default' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'google_analytics' => [
             { 'class_name' => 'Send', 'category' => 'Users', 'action' => 'Login', 'label' => 'Standard' }
           ]
-        }}
+        } }
       end
 
-      it "will show events" do
-        expect(subject).to match(%r{ga\(\"send\",{\"hitType\":\"event\",\"eventCategory\":\"Users\",\"eventAction\":\"Login\",\"eventLabel\":\"Standard\"}\)})
+      it 'will show events' do
+        expect(subject).to match(/ga\(\"send\",{\"hitType\":\"event\",\"eventCategory\":\"Users\",\"eventAction\":\"Login\",\"eventLabel\":\"Standard\"}\)/)
       end
     end
 
-    describe "with a event value" do
+    describe 'with a event value' do
       def env
-        {'tracker' => { 'google_analytics' => [
-          { 'class_name' => 'Send', category: "Users", action: "Login", label: "Standard", value: "5" }
-        ]}}
+        { 'tracker' => { 'google_analytics' => [
+          { 'class_name' => 'Send', :category => 'Users', :action => 'Login', :label => 'Standard', :value => '5' }
+        ] } }
       end
 
-      it "will show events with values" do
-        expect(subject).to match(%r{ga\(\"send\",{\"hitType\":\"event\",\"eventCategory\":\"Users\",\"eventAction\":\"Login\",\"eventLabel\":\"Standard\",\"eventValue\":\"5\"}\)},)
+      it 'will show events with values' do
+        expect(subject).to match(/ga\(\"send\",{\"hitType\":\"event\",\"eventCategory\":\"Users\",\"eventAction\":\"Login\",\"eventLabel\":\"Standard\",\"eventValue\":\"5\"}\)/)
       end
     end
   end
 
   describe 'with ecommerce events' do
-    describe "default" do
+    describe 'default' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'google_analytics' => [
             { 'class_name' => 'Ecommerce', 'type' => 'addItem', 'id' => '1234', 'name' => 'Fluffy Pink Bunnies', 'sku' => 'DD23444', 'category' => 'Party Toys', 'price' => '11.99', 'quantity' => '1' },
             { 'class_name' => 'Ecommerce', 'type' => 'addTransaction', 'id' => '1234', 'affiliation' => 'Acme Clothing', 'revenue' => 11.99, 'shipping' => '5', 'tax' => '1.29', 'currency' => 'EUR' }
           ]
-        }}
+        } }
       end
 
       subject { described_class.new(env, tracker: 'somebody', ecommerce: true).render }
 
-      it "will add items" do
+      it 'will add items' do
         attributes = { id: '1234', name: 'Fluffy Pink Bunnies', sku: 'DD23444', category: 'Party Toys', price: '11.99', quantity: '1' }.to_json
-        expect(subject).to match(%r{ga\(\"ecommerce:addItem\",#{attributes}\);})
+        expect(subject).to match(/ga\(\"ecommerce:addItem\",#{attributes}\);/)
       end
 
-      it "will add transaction" do
+      it 'will add transaction' do
         attributes = { id: '1234', affiliation: 'Acme Clothing', revenue: '11.99', shipping: '5', tax: '1.29', currency: 'EUR' }.to_json
-        expect(subject).to match(%r{ga\(\"ecommerce:addTransaction\",#{attributes}\);})
+        expect(subject).to match(/ga\(\"ecommerce:addTransaction\",#{attributes}\);/)
       end
 
-      it "will submit cart" do
-        expect(subject).to match(%r{ga\('ecommerce:send'\);})
+      it 'will submit cart' do
+        expect(subject).to match(/ga\('ecommerce:send'\);/)
       end
     end
   end
 
   describe 'with enhanced ecommerce events' do
-    describe "default" do
+    describe 'default' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'google_analytics' => [
             { 'class_name' => 'EnhancedEcommerce', 'type' => 'addProduct', 'id' => 'P12345', 'name' => 'Android Warhol T-Shirt', 'category' => 'Apparel', 'brand' => 'Google', 'variant' => 'black', 'price' => '29.20', 'coupon' => 'APPARELSALE', 'quantity' => 1 },
             { 'class_name' => 'EnhancedEcommerce', 'type' => 'setAction', 'label' => 'purchase' }
           ]
-        }}
+        } }
       end
 
       subject { described_class.new(env, tracker: 'somebody', enhanced_ecommerce: true).render }
 
-      it "will add product" do
+      it 'will add product' do
         attributes = { id: 'P12345', name: 'Android Warhol T-Shirt', category: 'Apparel', brand: 'Google', variant: 'black', price: '29.20', coupon: 'APPARELSALE', quantity: '1' }.to_json
-        expect(subject).to match(%r{ga\(\"ec:addProduct\",#{attributes}\);})
+        expect(subject).to match(/ga\(\"ec:addProduct\",#{attributes}\);/)
       end
 
-      it "will add action" do
-        expect(subject).to match(%r{ga\(\"ec:setAction\",\"purchase\"\);})
+      it 'will add action' do
+        expect(subject).to match(/ga\(\"ec:setAction\",\"purchase\"\);/)
       end
     end
   end
 
   describe 'with parameters events' do
     def env
-      {'tracker' => {
+      { 'tracker' => {
         'google_analytics' => [
-          { 'class_name' => 'Parameter', 'dimension1' => 'pink' },
+          { 'class_name' => 'Parameter', 'dimension1' => 'pink' }
         ]
-      }}
+      } }
     end
 
     subject { described_class.new(env, tracker: 'somebody').render }
 
-    it "will render dimension parameter" do
-      expect(subject).to match(%r{ga\('set', 'dimension1', 'pink'})
+    it 'will render dimension parameter' do
+      expect(subject).to match(/ga\('set', 'dimension1', 'pink'/)
     end
   end
 
-  describe "with custom domain" do
-    subject { described_class.new(env, tracker: 'somebody', cookie_domain: "railslabs.com").render }
+  describe 'with custom domain' do
+    subject { described_class.new(env, tracker: 'somebody', cookie_domain: 'railslabs.com').render }
 
-    it "will show asynchronous tracker with cookieDomain" do
-      expect(subject).to match(%r{ga\('create', 'somebody', {\"cookieDomain\":\"railslabs.com\"}\)})
-      expect(subject).to match(%r{ga\('send', 'pageview', window\.location\.pathname \+ window\.location\.search\)})
+    it 'will show asynchronous tracker with cookieDomain' do
+      expect(subject).to match(/ga\('create', 'somebody', {\"cookieDomain\":\"railslabs.com\"}\)/)
+      expect(subject).to match(/ga\('send', 'pageview', window\.location\.pathname \+ window\.location\.search\)/)
     end
   end
 
-  describe "with user_id tracking" do
-    subject { described_class.new(env, tracker: 'somebody', user_id: lambda { |env| return env[:user_id] } ).render }
+  describe 'with user_id tracking' do
+    subject { described_class.new(env, tracker: 'somebody', user_id: ->(env) { return env[:user_id] }).render }
 
-    it "will show asynchronous tracker with userId" do
-      expect(subject).to match(%r{ga\('create', 'somebody', {\"userId\":\"123\"}\)})
-      expect(subject).to match(%r{ga\('send', 'pageview', window\.location\.pathname \+ window\.location\.search\)})
+    it 'will show asynchronous tracker with userId' do
+      expect(subject).to match(/ga\('create', 'somebody', {\"userId\":\"123\"}\)/)
+      expect(subject).to match(/ga\('send', 'pageview', window\.location\.pathname \+ window\.location\.search\)/)
     end
   end
 
-  describe "with enhanced_link_attribution" do
+  describe 'with enhanced_link_attribution' do
     subject { described_class.new(env, tracker: 'happy', enhanced_link_attribution: true).render }
 
-    it "will embedded the linkid plugin script" do
-      expect(subject).to match(%r{linkid.js})
+    it 'will embedded the linkid plugin script' do
+      expect(subject).to match(/linkid.js/)
     end
   end
 
-  describe "with advertising" do
+  describe 'with advertising' do
     subject { described_class.new(env, tracker: 'happy', advertising: true).render }
 
-    it "will require displayfeatures" do
-      expect(subject).to match(%r{ga\('require', 'displayfeatures'\)})
+    it 'will require displayfeatures' do
+      expect(subject).to match(/ga\('require', 'displayfeatures'\)/)
     end
   end
 
-  describe "with enhanced ecommerce" do
+  describe 'with enhanced ecommerce' do
     subject { described_class.new(env, tracker: 'happy', enhanced_ecommerce: true).render }
 
-    it "will require the enhanced ecommerce plugin" do
-      expect(subject).to match(%r{ga\('require', 'ec'\)})
+    it 'will require the enhanced ecommerce plugin' do
+      expect(subject).to match(/ga\('require', 'ec'\)/)
     end
   end
 
-  describe "with ecommerce" do
+  describe 'with ecommerce' do
     subject { described_class.new(env, tracker: 'happy', ecommerce: true).render }
 
-    it "will require the ecommerce plugin" do
-      expect(subject).to match(%r{ga\('require', 'ecommerce', 'ecommerce\.js'\)})
+    it 'will require the ecommerce plugin' do
+      expect(subject).to match(/ga\('require', 'ecommerce', 'ecommerce\.js'\)/)
     end
   end
 
-  describe "with optimize" do
+  describe 'with optimize' do
     subject { described_class.new(env, tracker: 'happy', optimize: 'GTM-1234').render }
 
-    it "will require the optimize plugin with container ID" do
-      expect(subject).to match(%r{ga\('require', 'GTM-1234'\)})
+    it 'will require the optimize plugin with container ID' do
+      expect(subject).to match(/ga\('require', 'GTM-1234'\)/)
     end
   end
 
-  describe "with anonymizeIp" do
+  describe 'with anonymizeIp' do
     subject { described_class.new(env, tracker: 'happy', anonymize_ip: true).render }
 
-    it "will set anonymizeIp to true" do
-      expect(subject).to match(%r{ga\('set', 'anonymizeIp', true\)})
+    it 'will set anonymizeIp to true' do
+      expect(subject).to match(/ga\('set', 'anonymizeIp', true\)/)
     end
   end
 
-  describe "with dynamic tracker" do
-    subject { described_class.new(env, { tracker: lambda { |env| return env[:misc] }}).render }
+  describe 'with dynamic tracker' do
+    subject { described_class.new(env, { tracker: ->(env) { return env[:misc] } }).render }
 
     it 'will call tracker lambdas to obtain tracking codes' do
-      expect(subject).to match(%r{ga\('create', 'foobar', {}\)})
+      expect(subject).to match(/ga\('create', 'foobar', {}\)/)
     end
   end
 
   describe 'adjusted bounce rate' do
     subject { described_class.new(env, tracker: 'afake', adjusted_bounce_rate_timeouts: [15, 30]).render }
 
-    it "will add timeouts to push read events" do
-      expect(subject).to include %q{setTimeout(function() { ga('send', 'event', '15_seconds', 'read'); },15000)}
-      expect(subject).to include %q{setTimeout(function() { ga('send', 'event', '30_seconds', 'read'); },30000)}
+    it 'will add timeouts to push read events' do
+      expect(subject).to include "setTimeout(function() { ga('send', 'event', '15_seconds', 'read'); },15000)"
+      expect(subject).to include "setTimeout(function() { ga('send', 'event', '30_seconds', 'read'); },30000)"
     end
   end
 
   describe '#pageview_url_script' do
     context 'without custom pageview url script' do
-      subject { described_class.new(env, {} ) }
+      subject { described_class.new(env, {}) }
 
       it 'returns return the custom pageview url script' do
-        expect(subject.pageview_url_script).to eql ("window.location.pathname + window.location.search")
+        expect(subject.pageview_url_script).to eql 'window.location.pathname + window.location.search'
       end
     end
 
     context 'with a custom pageview url script' do
-      subject { described_class.new(env, { pageview_url_script: "{ 'page': location.pathname + location.search + location.hash }"}) }
+      subject { described_class.new(env, { pageview_url_script: "{ 'page': location.pathname + location.search + location.hash }" }) }
 
       it 'returns return the custom pageview url script' do
-        expect(subject.pageview_url_script).to eql ("{ 'page': location.pathname + location.search + location.hash }")
+        expect(subject.pageview_url_script).to eql "{ 'page': location.pathname + location.search + location.hash }"
       end
     end
 
     context 'with explicit_pageview disabled' do
-      subject { described_class.new(env, {tracker: 'afake', explicit_pageview: false }).render }
+      subject { described_class.new(env, { tracker: 'afake', explicit_pageview: false }).render }
 
       it 'does not send a pageview event' do
-        expect(subject).not_to include %q{ga('send', 'pageview',}
+        expect(subject).not_to include "ga('send', 'pageview',"
       end
     end
 
     context 'defaults to sending the pageview event' do
-      subject { described_class.new(env, {tracker: 'afake'}).render }
+      subject { described_class.new(env, { tracker: 'afake' }).render }
 
       it 'does not send a pageview event' do
         expect(subject).to include "ga('send', 'pageview'"
diff --git a/spec/handler/google_global_spec.rb b/spec/handler/google_global_spec.rb
index 0858020..1dfbcf2 100644
--- a/spec/handler/google_global_spec.rb
+++ b/spec/handler/google_global_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 RSpec.describe Rack::Tracker::GoogleGlobal do
   def env
     {
@@ -22,7 +24,7 @@ def env
     end
 
     context 'with an allowed option configured with a block' do
-      subject { described_class.new(env, user_id: lambda { |env| return env[:misc] }) }
+      subject { described_class.new(env, user_id: ->(env) { return env[:misc] }) }
 
       it 'returns hash with option set' do
         expect(subject.tracker_options).to eql ({ user_id: 'foobar' })
@@ -30,7 +32,7 @@ def env
     end
 
     context 'with an allowed option configured with a block returning nil' do
-      subject { described_class.new(env, user_id: lambda { |env| return env[:non_existing_key] }) }
+      subject { described_class.new(env, user_id: ->(env) { return env[:non_existing_key] }) }
 
       it 'returns an empty hash' do
         expect(subject.tracker_options).to eql ({})
@@ -56,7 +58,7 @@ def env
     end
 
     context 'with option configured with a block' do
-      subject { described_class.new(env, set: lambda { |env| return { option: env[:misc] } }) }
+      subject { described_class.new(env, set: ->(env) { return { option: env[:misc] } }) }
 
       it 'returns hash with option set' do
         expect(subject.set_options).to eql ({ option: 'foobar' })
@@ -64,161 +66,169 @@ def env
     end
 
     context 'with option configured with a block returning nil' do
-      subject { described_class.new(env, set: lambda { |env| return env[:non_existing_key] }) }
+      subject { described_class.new(env, set: ->(env) { return env[:non_existing_key] }) }
 
       it 'returns nil' do
         expect(subject.set_options).to be nil
       end
     end
   end
-  describe "with custom domain" do
-    let(:tracker) { { id: 'somebody'}}
-    let(:options) { { cookie_domain: "railslabs.com", trackers: [tracker] } }
+
+  describe 'with custom domain' do
+    let(:tracker) { { id: 'somebody' } }
+    let(:options) { { cookie_domain: 'railslabs.com', trackers: [tracker] } }
+
     subject { described_class.new(env, options).render }
 
-    it "will show asyncronous tracker with cookie_domain" do
-      expect(subject).to match(%r{gtag\('config', 'somebody', {\"cookie_domain\":\"railslabs.com\"}\)})
+    it 'will show asyncronous tracker with cookie_domain' do
+      expect(subject).to match(/gtag\('config', 'somebody', {\"cookie_domain\":\"railslabs.com\"}\)/)
     end
   end
 
-  describe "with user_id tracking" do
-    let(:tracker) { { id: 'somebody'}}
-    let(:options) { { user_id: lambda { |env| return env[:user_id] }, trackers: [tracker] } }
+  describe 'with user_id tracking' do
+    let(:tracker) { { id: 'somebody' } }
+    let(:options) { { user_id: ->(env) { return env[:user_id] }, trackers: [tracker] } }
+
     subject { described_class.new(env, options).render }
 
-    it "will show asyncronous tracker with userId" do
-      expect(subject).to match(%r{gtag\('config', 'somebody', {\"user_id\":\"123\"}\)})
+    it 'will show asyncronous tracker with userId' do
+      expect(subject).to match(/gtag\('config', 'somebody', {\"user_id\":\"123\"}\)/)
     end
   end
 
-  describe "with link_attribution" do
-    let(:tracker) { { id: 'happy'}}
+  describe 'with link_attribution' do
+    let(:tracker) { { id: 'happy' } }
     let(:options) { { link_attribution: true, trackers: [tracker] } }
+
     subject { described_class.new(env, options).render }
 
-    it "will show asyncronous tracker with link_attribution" do
-      expect(subject).to match(%r{gtag\('config', 'happy', {\"link_attribution\":true}\)})
+    it 'will show asyncronous tracker with link_attribution' do
+      expect(subject).to match(/gtag\('config', 'happy', {\"link_attribution\":true}\)/)
     end
   end
 
-  describe "with allow_display_features" do
-    let(:tracker) { { id: 'happy'}}
+  describe 'with allow_display_features' do
+    let(:tracker) { { id: 'happy' } }
     let(:options) { { allow_display_features: false, trackers: [tracker] } }
+
     subject { described_class.new(env, options).render }
 
-    it "will disable display features" do
-      expect(subject).to match(%r{gtag\('config', 'happy', {\"allow_display_features\":false}\)})
+    it 'will disable display features' do
+      expect(subject).to match(/gtag\('config', 'happy', {\"allow_display_features\":false}\)/)
     end
   end
 
-  describe "with anonymizeIp" do
-    let(:tracker) { { id: 'happy'}}
+  describe 'with anonymizeIp' do
+    let(:tracker) { { id: 'happy' } }
     let(:options) { { anonymize_ip: true, trackers: [tracker] } }
+
     subject { described_class.new(env, options).render }
 
-    it "will set anonymizeIp to true" do
-      expect(subject).to match(%r{gtag\('config', 'happy', {\"anonymize_ip\":true}\)})
+    it 'will set anonymizeIp to true' do
+      expect(subject).to match(/gtag\('config', 'happy', {\"anonymize_ip\":true}\)/)
     end
   end
 
-  describe "with dynamic tracker" do
-    let(:tracker) { { id: lambda { |env| return env[:misc] } }}
+  describe 'with dynamic tracker' do
+    let(:tracker) { { id: ->(env) { return env[:misc] } } }
     let(:options) { { trackers: [tracker] } }
+
     subject { described_class.new(env, options).render }
 
     it 'will call tracker lambdas to obtain tracking codes' do
-      expect(subject).to match(%r{gtag\('config', 'foobar', {}\)})
+      expect(subject).to match(/gtag\('config', 'foobar', {}\)/)
     end
   end
 
-  describe "with empty tracker" do
-    let(:present_tracker) { { id: 'present' }}
-    let(:empty_tracker) { { id: lambda { |env| return } }}
+  describe 'with empty tracker' do
+    let(:present_tracker) { { id: 'present' } }
+    let(:empty_tracker) { { id: ->(_env) { return } } }
     let(:options) { { trackers: [present_tracker, empty_tracker] } }
+
     subject { described_class.new(env, options).render }
 
     it 'will not render config' do
-      expect(subject).to match(%r{gtag\('config', 'present', {}\)})
-      expect(subject).not_to match(%r{gtag\('config', '', {}\)})
+      expect(subject).to match(/gtag\('config', 'present', {}\)/)
+      expect(subject).not_to match(/gtag\('config', '', {}\)/)
     end
   end
 
-  describe "with set options" do
+  describe 'with set options' do
     let(:tracker) { { id: 'with_options' } }
     let(:options) { { trackers: [tracker], set: { foo: 'bar' } } }
+
     subject { described_class.new(env, options).render }
 
     it 'will show set command' do
-      expect(subject).to match(%r{gtag\('set', {\"foo\":\"bar\"}\)})
+      expect(subject).to match(/gtag\('set', {\"foo\":\"bar\"}\)/)
     end
   end
 
-  describe "with virtual pages" do
+  describe 'with virtual pages' do
     subject { described_class.new(env, trackers: [{ id: 'somebody' }]).render }
 
-    describe "default" do
+    describe 'default' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'google_global' => [
             { 'class_name' => 'Page', 'path' => '/virtual_page' }
           ]
-        }}
+        } }
       end
 
-      it "will show virtual page" do
+      it 'will show virtual page' do
         expect(subject).to match(%r{gtag\('config', 'somebody', {\"page_path\":\"/virtual_page\"}\);})
       end
     end
 
-    describe "with a event value" do
+    describe 'with a event value' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'google_global' => [
             { 'class_name' => 'Page', 'path' => '/virtual_page', 'location' => 'https://example.com/virtual_page', 'title' => 'Virtual Page' }
           ]
-        }}
+        } }
       end
 
-      it "will show virtual page" do
+      it 'will show virtual page' do
         expect(subject).to match(%r{gtag\('config', 'somebody', {\"page_title\":\"Virtual Page\",\"page_location\":\"https:\/\/example.com\/virtual_page\",\"page_path\":\"/virtual_page\"}\);})
       end
     end
   end
 
-  describe "with events" do
+  describe 'with events' do
     subject { described_class.new(env, trackers: [{ id: 'somebody' }]).render }
 
-    describe "default" do
+    describe 'default' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'google_global' => [
             { 'class_name' => 'Event', 'action' => 'login' }
           ]
-        }}
+        } }
       end
 
-      it "will show the event" do
-        expect(subject).to match(%r{gtag\('event', 'login', {}\);})
+      it 'will show the event' do
+        expect(subject).to match(/gtag\('event', 'login', {}\);/)
       end
     end
 
-    describe "with event parameters" do
+    describe 'with event parameters' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'google_global' => [
             { 'class_name' => 'Event',
-              'action'     => 'login',
-              'category'   => 'engagement',
-              'label'      => 'Github',
-              'value'      => 5,
-              'transaction_id' => 1001,
-            }
+              'action' => 'login',
+              'category' => 'engagement',
+              'label' => 'Github',
+              'value' => 5,
+              'transaction_id' => 1001 }
           ]
-        }}
+        } }
       end
 
-      it "will show event" do
-        expect(subject).to match(%r{gtag\('event', 'login', {\"event_category\":\"engagement\",\"event_label\":\"Github\",\"value\":5,\"transaction_id\":1001}\);})
+      it 'will show event' do
+        expect(subject).to match(/gtag\('event', 'login', {\"event_category\":\"engagement\",\"event_label\":\"Github\",\"value\":5,\"transaction_id\":1001}\);/)
       end
     end
   end
diff --git a/spec/handler/google_tag_manager_spec.rb b/spec/handler/google_tag_manager_spec.rb
index ed1e147..523b9cc 100644
--- a/spec/handler/google_tag_manager_spec.rb
+++ b/spec/handler/google_tag_manager_spec.rb
@@ -1,5 +1,6 @@
-RSpec.describe Rack::Tracker::GoogleTagManager do
+# frozen_string_literal: true
 
+RSpec.describe Rack::Tracker::GoogleTagManager do
   def env
     {
       misc: 'foobar',
@@ -7,29 +8,29 @@ def env
     }
   end
 
-  describe "with events" do
-    describe "default" do
+  describe 'with events' do
+    describe 'default' do
       def env
-        {'tracker' => {
+        { 'tracker' => {
           'google_tag_manager' => [
-            { 'class_name' => 'Push', 'page' => 'Cart', 'price' => 50, 'content_ids' => ['sku_1', 'sku_2', 'sku_3'] }
+            { 'class_name' => 'Push', 'page' => 'Cart', 'price' => 50, 'content_ids' => %w[sku_1 sku_2 sku_3] }
           ]
-        }}
+        } }
       end
 
       subject { described_class.new(env, container: 'somebody').render_head }
-      it "will show events" do
-        expect(subject).to match(%r{"page":"Cart","price":50,"content_ids":\["sku_1","sku_2","sku_3"\]})
+
+      it 'will show events' do
+        expect(subject).to match(/"page":"Cart","price":50,"content_ids":\["sku_1","sku_2","sku_3"\]/)
       end
     end
   end
 
-  describe "with dynamic tracker" do
-    subject { described_class.new(env, { container: lambda { |env| return env[:misc] }}).render_head }
+  describe 'with dynamic tracker' do
+    subject { described_class.new(env, { container: ->(env) { return env[:misc] } }).render_head }
 
     it 'will call tracker lambdas to obtain tracking codes' do
-      expect(subject).to match(%r{\(window,document,'script','dataLayer','foobar'\)})
+      expect(subject).to match(/\(window,document,'script','dataLayer','foobar'\)/)
     end
   end
-
 end
diff --git a/spec/handler/handler_spec.rb b/spec/handler/handler_spec.rb
index 2fabeff..a89a1ce 100644
--- a/spec/handler/handler_spec.rb
+++ b/spec/handler/handler_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 RSpec.describe Rack::Tracker::Handler do
   def env
     { misc: 'foobar' }
@@ -15,14 +17,14 @@ def env
     context 'with overridden allowed_tracker_options' do
       subject do
         handler = described_class.new(env, {
-          static_option: 'value',
-          dynamic_option: lambda { |env| return env[:misc] },
-          dynamic_nil_option: lambda { |env| return env[:non_existent_key] },
-          non_allowed_option: 'value'
-        })
+                                        static_option: 'value',
+                                        dynamic_option: ->(env) { return env[:misc] },
+                                        dynamic_nil_option: ->(env) { return env[:non_existent_key] },
+                                        non_allowed_option: 'value'
+                                      })
 
         handler.allowed_tracker_options =
-          [:static_option, :dynamic_option, :dynamic_nil_option]
+          %i[static_option dynamic_option dynamic_nil_option]
 
         handler
       end
diff --git a/spec/handler/heap_spec.rb b/spec/handler/heap_spec.rb
index 7e48df4..7d59201 100644
--- a/spec/handler/heap_spec.rb
+++ b/spec/handler/heap_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 RSpec.describe Rack::Tracker::Heap do
   def env
     { foo: 'bar' }
diff --git a/spec/handler/hotjar_spec.rb b/spec/handler/hotjar_spec.rb
index c4a5855..698df29 100644
--- a/spec/handler/hotjar_spec.rb
+++ b/spec/handler/hotjar_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 RSpec.describe Rack::Tracker::Hotjar do
   def env
     { foo: 'bar' }
diff --git a/spec/handler/hubspot_spec.rb b/spec/handler/hubspot_spec.rb
index ea36178..a6ff5a7 100644
--- a/spec/handler/hubspot_spec.rb
+++ b/spec/handler/hubspot_spec.rb
@@ -1,5 +1,6 @@
-RSpec.describe Rack::Tracker::Hubspot do
+# frozen_string_literal: true
 
+RSpec.describe Rack::Tracker::Hubspot do
   def env
     { misc: '42' }
   end
diff --git a/spec/handler/vwo_spec.rb b/spec/handler/vwo_spec.rb
index 5b4fab6..1e6a7aa 100644
--- a/spec/handler/vwo_spec.rb
+++ b/spec/handler/vwo_spec.rb
@@ -1,12 +1,12 @@
-RSpec.describe Rack::Tracker::Vwo do
+# frozen_string_literal: true
 
+RSpec.describe Rack::Tracker::Vwo do
   def env
-    {misc: 'foobar'}
+    { misc: 'foobar' }
   end
 
   it 'will be placed in the head' do
     expect(described_class.position).to eq(:head)
     expect(described_class.new(env).position).to eq(:head)
   end
-
 end
diff --git a/spec/handler/zanox_spec.rb b/spec/handler/zanox_spec.rb
index dbf374d..0735e5c 100644
--- a/spec/handler/zanox_spec.rb
+++ b/spec/handler/zanox_spec.rb
@@ -1,20 +1,19 @@
-RSpec.describe Rack::Tracker::Zanox do
+# frozen_string_literal: true
 
+RSpec.describe Rack::Tracker::Zanox do
   describe Rack::Tracker::Zanox::Sale do
-
     subject { described_class.new(order_i_d: 'DEFC-4321', currency_symbol: 'EUR', total_price: '150.00') }
 
     describe '#write' do
-      specify { expect(subject.write).to eq "OrderID=[[DEFC-4321]]&CurrencySymbol=[[EUR]]&TotalPrice=[[150.00]]" }
+      specify { expect(subject.write).to eq 'OrderID=[[DEFC-4321]]&CurrencySymbol=[[EUR]]&TotalPrice=[[150.00]]' }
     end
   end
 
   describe Rack::Tracker::Zanox::Mastertag do
-
-    subject { described_class.new(id: "25GHTE9A07DF67DFG90T", category: 'Swimming', amount: '3.50', products: [{amount: '5', currency: 'EUR'}, {amount: '6', currency: 'USD'}]) }
+    subject { described_class.new(id: '25GHTE9A07DF67DFG90T', category: 'Swimming', amount: '3.50', products: [{ amount: '5', currency: 'EUR' }, { amount: '6', currency: 'USD' }]) }
 
     describe '#write' do
-      specify { expect(subject.write).to eq "var zx_category = \"Swimming\";\nvar zx_amount = \"3.50\";\nvar zx_products = [{\"amount\":\"5\",\"currency\":\"EUR\"},{\"amount\":\"6\",\"currency\":\"USD\"}];"}
+      specify { expect(subject.write).to eq "var zx_category = \"Swimming\";\nvar zx_amount = \"3.50\";\nvar zx_products = [{\"amount\":\"5\",\"currency\":\"EUR\"},{\"amount\":\"6\",\"currency\":\"USD\"}];" }
     end
   end
 
@@ -29,75 +28,77 @@ def env
 
   describe '#render #sale_events' do
     context 'with events' do
-      let(:env) {
+      let(:env) do
         {
           'tracker' => {
-          'zanox' =>
-            [
-              {
-                'CustomerID' => '123456',
-                'OrderId' => 'DEFC-4321',
-                'CurrencySymbol' => 'EUR',
-                'TotalPrice' => '150.00',
-                'class_name' => 'Sale',
-              }
-            ]
+            'zanox' =>
+                       [
+                         {
+                           'CustomerID' => '123456',
+                           'OrderId' => 'DEFC-4321',
+                           'CurrencySymbol' => 'EUR',
+                           'TotalPrice' => '150.00',
+                           'class_name' => 'Sale'
+                         }
+                       ]
           }
         }
-      }
+      end
 
       subject { described_class.new(env, options).render }
+
       let(:options) { { account_id: '123456H123456' } }
 
       it 'will display the correct tracking events' do
-        expect(subject).to include "https://ad.zanox.com/pps/?123456H123456&mode=[[1]]&CustomerID=[[123456]]&OrderId=[[DEFC-4321]]&CurrencySymbol=[[EUR]]&TotalPrice=[[150.00]]"
+        expect(subject).to include 'https://ad.zanox.com/pps/?123456H123456&mode=[[1]]&CustomerID=[[123456]]&OrderId=[[DEFC-4321]]&CurrencySymbol=[[EUR]]&TotalPrice=[[150.00]]'
       end
     end
   end
 
   describe '#render #lead_events' do
     context 'with events' do
-      let(:env) {
+      let(:env) do
         {
           'tracker' => {
-          'zanox' =>
-            [
-              {
-                'OrderId' => 'DEFC-4321',
-                'class_name' => 'Lead'
-              }
-            ]
+            'zanox' =>
+                       [
+                         {
+                           'OrderId' => 'DEFC-4321',
+                           'class_name' => 'Lead'
+                         }
+                       ]
           }
         }
-      }
+      end
 
       subject { described_class.new(env, options).render }
+
       let(:options) { { account_id: '123456H123456' } }
 
       it 'will display the correct tracking events' do
-        expect(subject).to include "https://ad.zanox.com/ppl/?123456H123456&mode=[[1]]&OrderId=[[DEFC-4321]]"
+        expect(subject).to include 'https://ad.zanox.com/ppl/?123456H123456&mode=[[1]]&OrderId=[[DEFC-4321]]'
       end
     end
   end
 
   describe '#render a #mastertag event' do
     context 'with events' do
-      let(:env) {
+      let(:env) do
         {
           'tracker' => {
-          'zanox' =>
-            [
-              {
-                'id' => '12345678D2345',
-                'class_name' => 'Mastertag',
-                'category' => 'Sewing',
-                'identifier' => '234',
-                'amount' => '5.90'
-              }
-            ]
+            'zanox' =>
+                       [
+                         {
+                           'id' => '12345678D2345',
+                           'class_name' => 'Mastertag',
+                           'category' => 'Sewing',
+                           'identifier' => '234',
+                           'amount' => '5.90'
+                         }
+                       ]
           }
         }
-      }
+      end
 
       subject { described_class.new(env, options).render }
 
diff --git a/spec/integration/bing_integration_spec.rb b/spec/integration/bing_integration_spec.rb
index e68b8fd..ad95f16 100644
--- a/spec/integration/bing_integration_spec.rb
+++ b/spec/integration/bing_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Bing Integration" do
+RSpec.describe 'Bing Integration' do
   before do
     setup_app(action: :bing) do |tracker|
       tracker.handler :bing, { tracker: '12345678' }
@@ -10,8 +12,7 @@
 
   subject { page }
 
-  it "embeds the script tag with tracker" do
-    expect(page.find("body")).to have_content('var o = {ti: "12345678"};')
+  it 'embeds the script tag with tracker' do
+    expect(page.find('body')).to have_content('var o = {ti: "12345678"};')
   end
-
 end
diff --git a/spec/integration/criteo_integration_spec.rb b/spec/integration/criteo_integration_spec.rb
index aa3df67..ae43490 100644
--- a/spec/integration/criteo_integration_spec.rb
+++ b/spec/integration/criteo_integration_spec.rb
@@ -1,32 +1,34 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Criteo Integration" do
+RSpec.describe 'Criteo Integration' do
   before do
     setup_app(action: :criteo) do |tracker|
       tracker.handler(:criteo, {
-        set_account: '1234',
-        set_customer_id: ->(env){ '4711' },
-        set_site_type: ->(env){ 'm' },
-        set_email: 'user@test.com'
-      })
+                        set_account: '1234',
+                        set_customer_id: ->(_env) { '4711' },
+                        set_site_type: ->(_env) { 'm' },
+                        set_email: 'user@test.com'
+                      })
     end
     visit '/'
   end
 
   subject { page }
 
-  it 'should include all the events' do
+  it 'includes all the events' do
     # tracker_events
-    expect(page.find("body")).to have_content "window.criteo_q.push({\"event\":\"setAccount\",\"account\":\"1234\"});"
-    expect(page.find("body")).to have_content "window.criteo_q.push({\"event\":\"setSiteType\",\"type\":\"m\"});"
-    expect(page.find("body")).to have_content "window.criteo_q.push({\"event\":\"setCustomerId\",\"id\":\"4711\"});"
-    expect(page.find("body")).to have_content "window.criteo_q.push({\"event\":\"setEmail\",\"email\":\"user@test.com\"});"
+    expect(page.find('body')).to have_content 'window.criteo_q.push({"event":"setAccount","account":"1234"});'
+    expect(page.find('body')).to have_content 'window.criteo_q.push({"event":"setSiteType","type":"m"});'
+    expect(page.find('body')).to have_content 'window.criteo_q.push({"event":"setCustomerId","id":"4711"});'
+    expect(page.find('body')).to have_content 'window.criteo_q.push({"event":"setEmail","email":"user@test.com"});'
 
     # events
-    expect(page.find("body")).to have_content "window.criteo_q.push({\"event\":\"viewItem\",\"item\":\"P001\"});"
-    expect(page.find("body")).to have_content "window.criteo_q.push({\"event\":\"viewList\",\"item\":[\"P001\",\"P002\"]});"
-    expect(page.find("body")).to have_content "window.criteo_q.push({\"event\":\"trackTransaction\",\"id\":\"id\",\"item\":{\"id\":\"P0038\",\"price\":\"6.54\",\"quantity\":1}});"
-    expect(page.find("body")).to have_content "window.criteo_q.push({\"event\":\"viewBasket\",\"item\":[{\"id\":\"P001\",\"price\":\"6.54\",\"quantity\":1},{\"id\":\"P0038\",\"price\":\"2.99\",\"quantity\":1}]});"
+    expect(page.find('body')).to have_content 'window.criteo_q.push({"event":"viewItem","item":"P001"});'
+    expect(page.find('body')).to have_content 'window.criteo_q.push({"event":"viewList","item":["P001","P002"]});'
+    expect(page.find('body')).to have_content 'window.criteo_q.push({"event":"trackTransaction","id":"id","item":{"id":"P0038","price":"6.54","quantity":1}});'
+    expect(page.find('body')).to have_content 'window.criteo_q.push({"event":"viewBasket","item":[{"id":"P001","price":"6.54","quantity":1},{"id":"P0038","price":"2.99","quantity":1}]});'
   end
 
   describe 'adjust tracker position via options' do
@@ -37,10 +39,9 @@
       visit '/'
     end
 
-    it "will be placed in the specified tag" do
-     expect(page.find("body")).to_not have_content('criteo')
-     expect(page.find("head")).to have_content("{\"event\":\"setAccount\",\"account\":\"1234\"}")
+    it 'will be placed in the specified tag' do
+      expect(page.find('body')).not_to have_content('criteo')
+      expect(page.find('head')).to have_content('{"event":"setAccount","account":"1234"}')
     end
-
   end
 end
diff --git a/spec/integration/drift_integration_spec.rb b/spec/integration/drift_integration_spec.rb
index 498538f..cbf10a2 100644
--- a/spec/integration/drift_integration_spec.rb
+++ b/spec/integration/drift_integration_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
 RSpec.describe 'Drift Integration' do
diff --git a/spec/integration/facebook_integration_spec.rb b/spec/integration/facebook_integration_spec.rb
index 456359a..96e9ddc 100644
--- a/spec/integration/facebook_integration_spec.rb
+++ b/spec/integration/facebook_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Facebook Integration" do
+RSpec.describe 'Facebook Integration' do
   before do
     setup_app(action: :facebook) do |tracker|
       tracker.handler :facebook, { custom_audience: 'my-audience' }
@@ -10,7 +12,7 @@
 
   subject { page }
 
-  it "embeds the script tag with tracking event from the controller action" do
+  it 'embeds the script tag with tracking event from the controller action' do
     expect(page).to have_content('window._fbq.push(["addPixelId", "my-audience"]);')
     expect(page.body).to include('https://www.facebook.com/tr?id=my-audience&amp;ev=PixelInitialized')
     expect(page).to have_content('window._fbq.push(["track","conversion-event",{"value":"1","currency":"EUR"}]);')
diff --git a/spec/integration/facebook_pixel_integration_spec.rb b/spec/integration/facebook_pixel_integration_spec.rb
index 07af9f0..5e245ce 100644
--- a/spec/integration/facebook_pixel_integration_spec.rb
+++ b/spec/integration/facebook_pixel_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Facebook Pixel Integration" do
+RSpec.describe 'Facebook Pixel Integration' do
   before do
     setup_app(action: :facebook_pixel) do |tracker|
       tracker.handler :facebook_pixel, { id: 'PIXEL_ID' }
@@ -10,7 +12,7 @@
 
   subject { page }
 
-  it "embeds the script tag with tracking event from the controller action" do
+  it 'embeds the script tag with tracking event from the controller action' do
     expect(page).to have_content("fbq('init', 'PIXEL_ID');")
     expect(page.body).to include('https://www.facebook.com/tr?id=PIXEL_ID&ev=PageView&noscript=1')
   end
@@ -20,7 +22,7 @@
     expect(page.body).to match(/fbq\("track", "CompleteRegistration", {\"value\":0.75,\"currency\":\"EUR\"}\);/)
   end
 
-  it "can use non-standard event names for audience building" do
+  it 'can use non-standard event names for audience building' do
     expect(page.body).to match(/fbq\("trackCustom", "FrequentShopper", {\"purchases\":24,\"category\":\"Sport\"}/)
   end
 end
diff --git a/spec/integration/go_squared_integration_spec.rb b/spec/integration/go_squared_integration_spec.rb
index d530c6d..97f9b78 100644
--- a/spec/integration/go_squared_integration_spec.rb
+++ b/spec/integration/go_squared_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "GoSquared Integration" do
+RSpec.describe 'GoSquared Integration' do
   subject { page }
 
   before do
@@ -18,39 +20,39 @@
     visit '/'
   end
 
-  it "adds the tracker to the page" do
+  it 'adds the tracker to the page' do
     expect(page).to have_content("_gs('123456');")
   end
 
-  it "adds the visitorName to the page" do
+  it 'adds the visitorName to the page' do
     expect(page).to have_content('_gs("set","visitorName","John Doe");')
   end
 
-  it "adds the visitor to the page" do
+  it 'adds the visitor to the page' do
     expect(page).to have_content('_gs("set","visitor",{"age":35,"favorite_food":"pizza"});')
   end
 
-  it "sets anonymizeIp" do
+  it 'sets anonymizeIp' do
     expect(page).to have_content("_gs('set', 'anonymizeIp', true);")
   end
 
-  it "sets cookieDomain" do
+  it 'sets cookieDomain' do
     expect(page).to have_content("_gs('set', 'cookieDomain', 'domain.com');")
   end
 
-  it "sets useCookies" do
+  it 'sets useCookies' do
     expect(page).to have_content("_gs('set', 'useCookies', true);")
   end
 
-  it "sets trackHash" do
+  it 'sets trackHash' do
     expect(page).to have_content("_gs('set', 'trackHash', true);")
   end
 
-  it "sets trackLocal" do
+  it 'sets trackLocal' do
     expect(page).to have_content("_gs('set', 'trackLocal', true);")
   end
 
-  it "sets trackParams" do
+  it 'sets trackParams' do
     expect(page).to have_content("_gs('set', 'trackParams', true);")
   end
 
@@ -64,7 +66,7 @@
       visit '/'
     end
 
-    it "adds the tracker to the page" do
+    it 'adds the tracker to the page' do
       expect(page).to have_content("_gs('12345', 'primaryTracker');")
       expect(page).to have_content("_gs('67890', 'secondaryTracker');")
     end
diff --git a/spec/integration/google_adwords_conversion_integration_spec.rb b/spec/integration/google_adwords_conversion_integration_spec.rb
index 2e64ce9..2563e65 100644
--- a/spec/integration/google_adwords_conversion_integration_spec.rb
+++ b/spec/integration/google_adwords_conversion_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Google Adwords Conversion Integration" do
+RSpec.describe 'Google Adwords Conversion Integration' do
   before do
     setup_app(action: :google_adwords_conversion) do |tracker|
       tracker.handler :google_adwords_conversion
@@ -10,9 +12,8 @@
 
   subject { page }
 
-  it "embeds the script tag with tracking event from the controller action" do
-    expect(page.find("body")).to have_content("var google_conversion_id = 123456;\nvar google_conversion_language = 'en';\nvar google_conversion_format = '3';\nvar google_conversion_color = 'ffffff';\nvar google_conversion_label = 'Conversion Label';")
-    expect(page.find("body")).to have_xpath("//img[@src=\"//www.googleadservices.com/pagead/conversion/123456/?label=Conversion%20Label&guid=ON&script=0\"]")
+  it 'embeds the script tag with tracking event from the controller action' do
+    expect(page.find('body')).to have_content("var google_conversion_id = 123456;\nvar google_conversion_language = 'en';\nvar google_conversion_format = '3';\nvar google_conversion_color = 'ffffff';\nvar google_conversion_label = 'Conversion Label';")
+    expect(page.find('body')).to have_xpath('//img[@src="//www.googleadservices.com/pagead/conversion/123456/?label=Conversion%20Label&guid=ON&script=0"]')
   end
-
 end
diff --git a/spec/integration/google_analytics_integration_spec.rb b/spec/integration/google_analytics_integration_spec.rb
index ba59ea2..2183a68 100644
--- a/spec/integration/google_analytics_integration_spec.rb
+++ b/spec/integration/google_analytics_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Google Analytics Integration" do
+RSpec.describe 'Google Analytics Integration' do
   before do
     setup_app(action: :google_analytics) do |tracker|
       tracker.handler :google_analytics, { tracker: 'U-XXX-Y' }
@@ -10,14 +12,14 @@
 
   subject { page }
 
-  it "embeds the script tag with tracking event from the controller action" do
-    expect(page.find("head")).to have_content('ga("ecommerce:addItem",{"id":"1234","name":"Fluffy Pink Bunnies","sku":"DD23444","category":"Party Toys","price":"11.99","quantity":"1"})')
-    expect(page.find("head")).to have_content('ga("ecommerce:addTransaction",{"id":"1234","affiliation":"Acme Clothing","revenue":"11.99","shipping":"5","tax":"1.29"})')
-    expect(page.find("head")).to have_content('ga("send",{"hitType":"event","eventCategory":"button","eventAction":"click","eventLabel":"nav-buttons","eventValue":"X"})')
+  it 'embeds the script tag with tracking event from the controller action' do
+    expect(page.find('head')).to have_content('ga("ecommerce:addItem",{"id":"1234","name":"Fluffy Pink Bunnies","sku":"DD23444","category":"Party Toys","price":"11.99","quantity":"1"})')
+    expect(page.find('head')).to have_content('ga("ecommerce:addTransaction",{"id":"1234","affiliation":"Acme Clothing","revenue":"11.99","shipping":"5","tax":"1.29"})')
+    expect(page.find('head')).to have_content('ga("send",{"hitType":"event","eventCategory":"button","eventAction":"click","eventLabel":"nav-buttons","eventValue":"X"})')
   end
 
-  it "will have default pageview url script" do
-    expect(page.find("head")).to have_content("ga('send', 'pageview', window.location.pathname + window.location.search);")
+  it 'will have default pageview url script' do
+    expect(page.find('head')).to have_content("ga('send', 'pageview', window.location.pathname + window.location.search);")
   end
 
   describe 'adjust tracker position via options' do
@@ -28,9 +30,9 @@
       visit '/'
     end
 
-    it "will be placed in the specified tag" do
-     expect(page.find("head")).to_not have_content('U-XXX-Y')
-     expect(page.find("body")).to have_content('ga("ecommerce:addItem",{"id":"1234","name":"Fluffy Pink Bunnies","sku":"DD23444","category":"Party Toys","price":"11.99","quantity":"1"})')
+    it 'will be placed in the specified tag' do
+      expect(page.find('head')).not_to have_content('U-XXX-Y')
+      expect(page.find('body')).to have_content('ga("ecommerce:addItem",{"id":"1234","name":"Fluffy Pink Bunnies","sku":"DD23444","category":"Party Toys","price":"11.99","quantity":"1"})')
     end
   end
 
@@ -42,29 +44,28 @@
       visit '/'
     end
 
-    it "will not mess up the html" do
+    it 'will not mess up the html' do
       expect(page.find('head')).to have_content('U-XXX-Y')
       # Backslashes are also escaped, thus \' becomes in \\\' in output
-      expect(page.find('head')).to have_content %q{Some escaped \\\\\\'value}
+      expect(page.find('head')).to have_content "Some escaped \\\\\\'value"
     end
 
-    it "automatically escape javascript in dimensions" do
+    it 'automatically escape javascript in dimensions' do
       expect(page.find('head')).to have_content('U-XXX-Y')
-      expect(page.find('head')).to have_content %q{Author\\'s name}
+      expect(page.find('head')).to have_content "Author\\'s name"
     end
   end
 
   describe 'Use custom pageview script' do
     before do
       setup_app(action: :google_analytics) do |tracker|
-        tracker.handler :google_analytics, { tracker: 'U-XXX-Y', pageview_url_script: "{ 'page': location.pathname + location.search + location.hash }"}
+        tracker.handler :google_analytics, { tracker: 'U-XXX-Y', pageview_url_script: "{ 'page': location.pathname + location.search + location.hash }" }
       end
       visit '/'
     end
 
-    it "will use the custom pageview script for the pageview event" do
-      expect(page.find("head")).to have_content("ga('send', 'pageview', { 'page': location.pathname + location.search + location.hash });")
+    it 'will use the custom pageview script for the pageview event' do
+      expect(page.find('head')).to have_content("ga('send', 'pageview', { 'page': location.pathname + location.search + location.hash });")
     end
   end
-
 end
diff --git a/spec/integration/google_global_integration_spec.rb b/spec/integration/google_global_integration_spec.rb
index 14df465..44d2529 100644
--- a/spec/integration/google_global_integration_spec.rb
+++ b/spec/integration/google_global_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Google Global Integration Integration" do
+RSpec.describe 'Google Global Integration Integration' do
   before do
     setup_app(action: :google_global) do |tracker|
       tracker.handler :google_global, tracker_options
@@ -10,32 +12,32 @@
 
   let(:tracker_options) { { trackers: [{ id: 'U-XXX-Y' }] } }
 
-  it "embeds the script tag with tracking event from the controller action" do
-    expect(page.find("head")).to have_content('U-XXX-Y')
+  it 'embeds the script tag with tracking event from the controller action' do
+    expect(page.find('head')).to have_content('U-XXX-Y')
   end
 
   describe 'adjust tracker position via options' do
     let(:tracker_options) { { trackers: [{ id: 'U-XXX-Y' }], position: :body } }
 
-    it "will be placed in the specified tag" do
-     expect(page.find("head")).to_not have_content('U-XXX-Y')
-     expect(page.find("body")).to have_content('U-XXX-Y')
+    it 'will be placed in the specified tag' do
+      expect(page.find('head')).not_to have_content('U-XXX-Y')
+      expect(page.find('body')).to have_content('U-XXX-Y')
     end
   end
 
-  describe "handles empty tracker id" do
-    let(:tracker_options) { { trackers: [{ id: nil }, { id: "" }, { id: "  " }] } }
+  describe 'handles empty tracker id' do
+    let(:tracker_options) { { trackers: [{ id: nil }, { id: '' }, { id: '  ' }] } }
 
-    it "does not inject scripts" do
-      expect(page.find("head")).to_not have_content("<script async src='https://www.googletagmanager.com/gtag/js?id=")
+    it 'does not inject scripts' do
+      expect(page.find('head')).not_to have_content("<script async src='https://www.googletagmanager.com/gtag/js?id=")
     end
   end
 
-  describe "callable tracker id" do
-    let(:tracker_options) { { trackers: [{ id: proc { "U-XXX-Y" } }] } }
+  describe 'callable tracker id' do
+    let(:tracker_options) { { trackers: [{ id: proc { 'U-XXX-Y' } }] } }
 
-    it "is injected into head with id from proc" do
-      expect(page.find("head")).to have_content('U-XXX-Y')
+    it 'is injected into head with id from proc' do
+      expect(page.find('head')).to have_content('U-XXX-Y')
     end
   end
 end
diff --git a/spec/integration/google_tag_manager_integration_spec.rb b/spec/integration/google_tag_manager_integration_spec.rb
index f8fe375..036e965 100644
--- a/spec/integration/google_tag_manager_integration_spec.rb
+++ b/spec/integration/google_tag_manager_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Google Tag Manager Integration" do
+RSpec.describe 'Google Tag Manager Integration' do
   before do
     setup_app(action: :google_tag_manager) do |tracker|
       tracker.handler :google_tag_manager, { container: 'GTM-ABCDEF' }
@@ -9,27 +11,27 @@
 
   subject { page }
 
-  it "embeds the script tag with tracking event from the controller action" do
+  it 'embeds the script tag with tracking event from the controller action' do
     visit '/'
-    expect(page.find("head")).to have_content 'GTM-ABCDEF'
-    expect(page.find("head")).to have_content "dataLayer.push({\"click\":\"X\",\"price\":10}, {\"transactionProducts\":[{\"sku\":\"DD44\",\"name\":\"T-shirt\"},{\"sku\":\"DD66\",\"name\":\"Jeans\"}]});"
-    expect(page.find("body")).to have_xpath '//body/noscript/iframe[@src="https://www.googletagmanager.com/ns.html?id=GTM-ABCDEF"]'
+    expect(page.find('head')).to have_content 'GTM-ABCDEF'
+    expect(page.find('head')).to have_content 'dataLayer.push({"click":"X","price":10}, {"transactionProducts":[{"sku":"DD44","name":"T-shirt"},{"sku":"DD66","name":"Jeans"}]});'
+    expect(page.find('body')).to have_xpath '//body/noscript/iframe[@src="https://www.googletagmanager.com/ns.html?id=GTM-ABCDEF"]'
   end
 
-  it "does not inject a dataLayer if no events are set " do
+  it 'does not inject a dataLayer if no events are set ' do
     visit '/?no_events=true'
-    expect(page.find("head")).to have_content 'GTM-ABCDEF'
-    expect(page.find("head")).to_not have_content "dataLayer.push("
-    expect(page.find("body")).to have_xpath '//body/noscript/iframe[@src="https://www.googletagmanager.com/ns.html?id=GTM-ABCDEF"]'
+    expect(page.find('head')).to have_content 'GTM-ABCDEF'
+    expect(page.find('head')).not_to have_content 'dataLayer.push('
+    expect(page.find('body')).to have_xpath '//body/noscript/iframe[@src="https://www.googletagmanager.com/ns.html?id=GTM-ABCDEF"]'
   end
 
-  it "embeds the turbolinks observer if requested" do
+  it 'embeds the turbolinks observer if requested' do
     visit '/'
-    expect(page.find("head")).to_not have_content "turbolinks:load"
+    expect(page.find('head')).not_to have_content 'turbolinks:load'
     setup_app(action: :google_tag_manager) do |tracker|
       tracker.handler :google_tag_manager, { container: 'GTM-ABCDEF', turbolinks: true }
     end
     visit '/'
-    expect(page.find("head")).to have_content "turbolinks:load"
+    expect(page.find('head')).to have_content 'turbolinks:load'
   end
-end
\ No newline at end of file
+end
diff --git a/spec/integration/heap_integration_spec.rb b/spec/integration/heap_integration_spec.rb
index ff866a1..a0f2c7a 100644
--- a/spec/integration/heap_integration_spec.rb
+++ b/spec/integration/heap_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Heap Integration" do
+RSpec.describe 'Heap Integration' do
   before do
     setup_app(action: :heap) do |tracker|
       tracker.handler :heap, { env_id: '12341234' }
diff --git a/spec/integration/hotjar_integration_spec.rb b/spec/integration/hotjar_integration_spec.rb
index 301a801..24491f5 100644
--- a/spec/integration/hotjar_integration_spec.rb
+++ b/spec/integration/hotjar_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Hotjar Integration" do
+RSpec.describe 'Hotjar Integration' do
   before do
     setup_app(action: :hotjar) do |tracker|
       tracker.handler :hotjar, { site_id: '4711' }
diff --git a/spec/integration/hubspot_integration_spec.rb b/spec/integration/hubspot_integration_spec.rb
index 4414aa4..ad86226 100644
--- a/spec/integration/hubspot_integration_spec.rb
+++ b/spec/integration/hubspot_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Hubspot Integration" do
+RSpec.describe 'Hubspot Integration' do
   before do
     setup_app(action: :hubspot) do |tracker|
       tracker.handler :hubspot, { site_id: '123456' }
@@ -9,11 +11,10 @@
     visit '/'
   end
 
-
   subject { page }
 
-  it "embeds the site-specifc script tag" do
-    expect(page).to have_xpath("//script", id: "hs-script-loader" )
-    expect(page.find("script")[:src]).to eq("//js.hs-scripts.com/123456.js")
+  it 'embeds the site-specifc script tag' do
+    expect(page).to have_xpath('//script', id: 'hs-script-loader')
+    expect(page.find('script')[:src]).to eq('//js.hs-scripts.com/123456.js')
   end
 end
diff --git a/spec/integration/rails_integration_spec.rb b/spec/integration/rails_integration_spec.rb
index ec932f0..597b6e0 100644
--- a/spec/integration/rails_integration_spec.rb
+++ b/spec/integration/rails_integration_spec.rb
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "Rails Integration" do
+RSpec.describe 'Rails Integration' do
   let(:callable_skip_inject) do
-    lambda do |env|
+    lambda do |_env|
       # check for anything in the env hash to decide
       # if you return the `tracker id` or `nil` to skip injection
       nil
@@ -40,7 +42,7 @@
     HTML
   end
 
-  it "embeds the script tag with tracking event from the controller action" do
+  it 'embeds the script tag with tracking event from the controller action' do
     expect(subject).to eql(expected_html)
   end
 end
diff --git a/spec/integration/vwo_integration_spec.rb b/spec/integration/vwo_integration_spec.rb
index 80807ce..1015fe4 100644
--- a/spec/integration/vwo_integration_spec.rb
+++ b/spec/integration/vwo_integration_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'support/capybara_app_helper'
 
-RSpec.describe "VWO Integration" do
+RSpec.describe 'VWO Integration' do
   before do
     setup_app(action: :vwo) do |tracker|
       tracker.handler :vwo, { account_id: '123456' }
@@ -11,7 +13,7 @@
 
   subject { page }
 
-  it "embeds the script tag" do
+  it 'embeds the script tag' do
     expect(page).to have_content("this.load('//dev.visualwebsiteoptimizer.com/j.php?a='+ '123456'")
   end
 end
diff --git a/spec/integration/zanox_integration_spec.rb b/spec/integration/zanox_integration_spec.rb
index b1f5f4b..39b2e6a 100644
--- a/spec/integration/zanox_integration_spec.rb
+++ b/spec/integration/zanox_integration_spec.rb
@@ -1,10 +1,11 @@
-require 'support/capybara_app_helper'
+# frozen_string_literal: true
 
-RSpec.describe "Zanox Integration" do
+require 'support/capybara_app_helper'
 
+RSpec.describe 'Zanox Integration' do
   before do
     setup_app(action: :zanox) do |tracker|
-      tracker.handler(:zanox, { account_id: '12345H123456789' } )
+      tracker.handler(:zanox, { account_id: '12345H123456789' })
     end
 
     visit '/'
@@ -12,16 +13,16 @@
 
   subject { page }
 
-  it 'should include the mastertag event' do
-    expect(page.find("body")).to have_content "window._zx.push({\"id\": \"blurg567\"});"
+  it 'includes the mastertag event' do
+    expect(page.find('body')).to have_content 'window._zx.push({"id": "blurg567"});'
     expect(page).to have_content "var zx_category = \"cake decorating\";\nvar zx_amount = \"5.90\";\n"
   end
 
-  it 'should include the sale event' do
+  it 'includes the sale event' do
     expect(page).to have_xpath "//script[contains(@src,'pps/?12345H123456789&mode=[[1]]&CustomerID=[[123456]]&OrderID=[[DEFC-4321]]&CurrencySymbol=[[EUR]]&TotalPrice=[[150.00]]')]"
   end
 
-  it 'should include the lead event' do
+  it 'includes the lead event' do
     expect(page).to have_xpath "//script[contains(@src,'ppl/?12345H123456789&mode=[[1]]&CustomerID=[[654321]]')]"
   end
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 39b3f24..a0627cc 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
 $LOAD_PATH.unshift(File.dirname(__FILE__))
 
@@ -9,7 +11,7 @@
 
 # Requires supporting files with custom matchers and macros, etc,
 # in ./support/ and its subdirectories.
-Dir["#{File.dirname(__FILE__)}/support/**/*.rb"].each {|f| require f}
+Dir["#{File.dirname(__FILE__)}/support/**/*.rb"].sort.each { |f| require f }
 
 Capybara.ignore_hidden_elements = false
 
diff --git a/spec/support/capybara_app_helper.rb b/spec/support/capybara_app_helper.rb
index 3125e9c..9148f7f 100644
--- a/spec/support/capybara_app_helper.rb
+++ b/spec/support/capybara_app_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'support/metal_controller'
 
 # helper to configure the middleware stack with custom handlers
@@ -14,7 +16,7 @@
 #
 # By default this dispatches to a metal controller as a simple rack endpoint
 # like rails would do, but without booting up a full rails environment.
-def setup_app(options={}, &block)
+def setup_app(options = {}, &block)
   rack_endpoint     = options[:endpoint] || MetalController
   controller_action = options[:action]
 
diff --git a/spec/support/fake_handler.rb b/spec/support/fake_handler.rb
index c40c1e5..e1a216e 100644
--- a/spec/support/fake_handler.rb
+++ b/spec/support/fake_handler.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 class TrackAllTheThings < Rack::Tracker::Handler
   def render
-    Tilt.new( File.join( File.dirname(__FILE__), '../fixtures/track_all_the_things.erb') ).render(self)
+    Tilt.new(File.join(File.dirname(__FILE__), '../fixtures/track_all_the_things.erb')).render(self)
   end
 
   def self.track(name, event)
@@ -12,12 +14,11 @@ def track_me
   end
 end
 
-
 class AnotherHandler < Rack::Tracker::Handler
   self.position = :body
 
   def render
-    Tilt.new( File.join( File.dirname(__FILE__), '../fixtures/another_handler.erb') ).render(self)
+    Tilt.new(File.join(File.dirname(__FILE__), '../fixtures/another_handler.erb')).render(self)
   end
 
   def self.track(name, event)
diff --git a/spec/support/metal_controller.rb b/spec/support/metal_controller.rb
index f22447e..9209daf 100644
--- a/spec/support/metal_controller.rb
+++ b/spec/support/metal_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'action_controller'
 
 class MetalController < ActionController::Metal
@@ -19,11 +21,11 @@ def turing
       t.track_all_the_things like: 'turing'
       t.another_handler likes: 'turing'
     end
-    render "metal/turing", layout: false
+    render 'metal/turing', layout: false
   end
 
   def do_not_track_alan
-    render "metal/turing", layout: false
+    render 'metal/turing', layout: false
   end
 
   def index
@@ -31,14 +33,14 @@ def index
       t.track_all_the_things like: 'no-one-else'
       t.another_handler likes: 'you'
     end
-    render "metal/index"
+    render 'metal/index'
   end
 
   def facebook
     tracker do |t|
       t.facebook :track, { id: 'conversion-event', value: '1', currency: 'EUR' }
     end
-    render "metal/index"
+    render 'metal/index'
   end
 
   def facebook_pixel
@@ -47,7 +49,7 @@ def facebook_pixel
       t.facebook_pixel :track, { type: 'CompleteRegistration', options: { value: 0.75, currency: 'EUR' } }
       t.facebook_pixel :track_custom, { type: 'FrequentShopper', options: { purchases: 24, category: 'Sport' } }
     end
-    render "metal/index"
+    render 'metal/index'
   end
 
   def google_analytics
@@ -55,14 +57,14 @@ def google_analytics
       t.google_analytics :ecommerce, { type: 'addTransaction', id: 1234, affiliation: 'Acme Clothing', revenue: 11.99, shipping: 5, tax: 1.29 }
       t.google_analytics :ecommerce, { type: 'addItem', id: 1234, name: 'Fluffy Pink Bunnies', sku: 'DD23444', category: 'Party Toys', price: 11.99, quantity: 1 }
       t.google_analytics :send, { type: 'event', category: 'button', action: 'click', label: 'nav-buttons', value: 'X' }
-      t.google_analytics :parameter, dimension1: %q{Some escaped \\'value}
-      t.google_analytics :parameter, dimension2: %q{Author's name}
+      t.google_analytics :parameter, dimension1: "Some escaped \\'value"
+      t.google_analytics :parameter, dimension2: "Author's name"
     end
-    render "metal/index"
+    render 'metal/index'
   end
 
   def google_global
-    render "metal/index"
+    render 'metal/index'
   end
 
   def google_tag_manager
@@ -72,18 +74,18 @@ def google_tag_manager
         t.google_tag_manager :push, transactionProducts: [{ sku: 'DD44', name: 'T-shirt' }, { sku: 'DD66', name: 'Jeans' }]
       end
     end
-    render "metal/index"
+    render 'metal/index'
   end
 
   def google_adwords_conversion
     tracker do |t|
-      t.google_adwords_conversion :conversion, { id: 123456, language: 'en', format: '3', color: 'ffffff', label: 'Conversion Label' }
+      t.google_adwords_conversion :conversion, { id: 123_456, language: 'en', format: '3', color: 'ffffff', label: 'Conversion Label' }
     end
-    render "metal/index"
+    render 'metal/index'
   end
 
   def vwo
-    render "metal/index"
+    render 'metal/index'
   end
 
   def go_squared
@@ -91,22 +93,22 @@ def go_squared
       t.go_squared :visitor_name, { name: 'John Doe' }
       t.go_squared :visitor_info, { age: 35, favorite_food: 'pizza' }
     end
-    render "metal/index"
+    render 'metal/index'
   end
 
   def criteo
     tracker do |t|
       t.criteo :view_item, { item: 'P001' }
-      t.criteo :view_list, { item: ['P001', 'P002'] }
-      t.criteo :track_transaction, { id: 'id', item: { id: "P0038", price:"6.54", quantity:1 } }
-      t.criteo :view_basket, { item: [{ id: "P001", price:"6.54", quantity:1 }, { id: "P0038", price:"2.99", quantity:1 }] }
+      t.criteo :view_list, { item: %w[P001 P002] }
+      t.criteo :track_transaction, { id: 'id', item: { id: 'P0038', price: '6.54', quantity: 1 } }
+      t.criteo :view_basket, { item: [{ id: 'P001', price: '6.54', quantity: 1 }, { id: 'P0038', price: '2.99', quantity: 1 }] }
     end
     render 'metal/index'
   end
 
   def zanox
     tracker do |t|
-      t.zanox :mastertag, { id: 'blurg567', category: 'cake decorating', amount: '5.90'}
+      t.zanox :mastertag, { id: 'blurg567', category: 'cake decorating', amount: '5.90' }
       t.zanox :sale, { customer_i_d: '123456', order_i_d: 'DEFC-4321', currency_symbol: 'EUR', total_price: '150.00' }
       t.zanox :lead, { customer_i_d: '654321' }
     end
@@ -114,22 +116,22 @@ def zanox
   end
 
   def hotjar
-    render "metal/index"
+    render 'metal/index'
   end
 
   def hubspot
-    render "metal/index"
+    render 'metal/index'
   end
 
   def bing
-    render "metal/index"
+    render 'metal/index'
   end
 
   def drift
-    render "metal/index"
+    render 'metal/index'
   end
 
   def heap
-    render "metal/index"
+    render 'metal/index'
   end
 end
diff --git a/spec/tracker/controller_spec.rb b/spec/tracker/controller_spec.rb
index 52d30b2..47febb8 100644
--- a/spec/tracker/controller_spec.rb
+++ b/spec/tracker/controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 TestController = Struct.new(:env) do
   include Rack::Tracker::Controller
 
@@ -8,7 +10,7 @@ def index
         type: 'addTransaction',
         some: 'thing'
       }
-      %w(foo bar).each do |item|
+      %w[foo bar].each do |item|
         t.google_analytics :ecommerce, {
           type: 'addItem',
           name: item
@@ -19,7 +21,6 @@ def index
   end
 end
 
-
 RSpec.describe Rack::Tracker::Controller do
   describe '#tracker' do
     let(:send)       { { 'category' => 'foo', 'class_name' => 'Send' } }
@@ -31,11 +32,9 @@ def index
 
     context 'controller' do
       it 'writes the event into env' do
-        expect {
+        expect do
           controller.index
-        }.to change {
-          controller.env
-        }.from({}).to('tracker' => {'google_analytics' => [send, trx, item_foo, item_bar], 'facebook' => [fb_event]})
+        end.to change(controller, :env).from({}).to('tracker' => { 'google_analytics' => [send, trx, item_foo, item_bar], 'facebook' => [fb_event] })
       end
     end
   end
diff --git a/spec/tracker/handler_delegator_spec.rb b/spec/tracker/handler_delegator_spec.rb
index 2fa2bb8..5c57275 100644
--- a/spec/tracker/handler_delegator_spec.rb
+++ b/spec/tracker/handler_delegator_spec.rb
@@ -1,10 +1,10 @@
+# frozen_string_literal: true
+
 Foo = Class.new
 Bar = Class.new
 
 RSpec.describe Rack::Tracker::HandlerDelegator do
-
   describe '#handler' do
-
     it 'will find handler in the Rack::Tracker namespace' do
       expect(described_class.handler(:google_analytics)).to eq(Rack::Tracker::GoogleAnalytics)
     end
@@ -18,9 +18,7 @@
     end
 
     it 'will raise when no handler is found' do
-      expect { described_class.handler(:baz)}.to raise_error(ArgumentError, "No such Handler: Baz")
+      expect { described_class.handler(:baz) }.to raise_error(ArgumentError, 'No such Handler: Baz')
     end
-
   end
-
 end
diff --git a/spec/tracker/handler_set_spec.rb b/spec/tracker/handler_set_spec.rb
index e3f411c..c20d469 100644
--- a/spec/tracker/handler_set_spec.rb
+++ b/spec/tracker/handler_set_spec.rb
@@ -1,22 +1,24 @@
+# frozen_string_literal: true
+
 class Dummy < Rack::Tracker::Handler
 end
 
 RSpec.describe Rack::Tracker::HandlerSet do
-
   let(:set) do
-    Rack::Tracker::HandlerSet.new do
-      handler 'dummy', {foo: "bar"}
+    described_class.new do
+      handler 'dummy', { foo: 'bar' }
     end
   end
 
   describe '#each' do
     subject { set.each }
+
     specify { expect(subject.to_a.size).to eq(1) }
     specify { expect(subject).to match_array(Dummy) }
   end
 
   describe Rack::Tracker::HandlerSet::Handler do
-    subject { described_class.new(Dummy, {foo: 'bar'}) }
+    subject { described_class.new(Dummy, { foo: 'bar' }) }
 
     describe '#init' do
       it 'will initialize the handler with the given class' do
@@ -24,9 +26,8 @@ class Dummy < Rack::Tracker::Handler
       end
 
       it 'will initialize the handler with the given options' do
-        expect(subject.init({}).options).to eq({foo: 'bar'})
+        expect(subject.init({}).options).to eq({ foo: 'bar' })
       end
     end
   end
-
 end
diff --git a/spec/tracker/javascript_helper_spec.rb b/spec/tracker/javascript_helper_spec.rb
index fc36815..9745611 100644
--- a/spec/tracker/javascript_helper_spec.rb
+++ b/spec/tracker/javascript_helper_spec.rb
@@ -1,5 +1,6 @@
-RSpec.describe Rack::Tracker do
+# frozen_string_literal: true
 
+RSpec.describe Rack::Tracker do
   let(:escaper) do
     Class.new { include Rack::Tracker::JavaScriptHelper }.new
   end
@@ -7,11 +8,11 @@
   subject { escaper }
 
   # Instance methods are mixed in
-  it { should respond_to :escape_javascript }
-  it { should respond_to :j }
+  it { is_expected.to respond_to :escape_javascript }
+  it { is_expected.to respond_to :j }
 
   context 'with plain values' do
-    it 'should return untouched values' do
+    it 'returns untouched values' do
       expect(escaper.j('Hello')).to eq 'Hello'
     end
   end
@@ -19,12 +20,11 @@
   # The following is a RSpec port of original rails's test suite for #j method.
   # https://github.com/rails/rails/blob/master/actionview/test/template/javascript_helper_test.rb
   describe '#escape_javascript' do
-
     # Simple matcher to shorten specs
     matcher :escape do |value|
-
       match do |actual|
         raise ArgumentError, 'macther syntax is escape("some value").to("expected value")' unless @expected
+
         actual.j(value) == @expected
       end
 
@@ -35,17 +35,15 @@
       end
     end
 
-    it { should escape(nil).to '' }
-    it { should escape(%(This "thing" is really\n netos')).to %(This \\"thing\\" is really\\n netos\\') }
-    it { should escape(%(backslash\\test)).to %(backslash\\\\test) }
-    it { should escape(%(dont </close> tags)).to %(dont <\\/close> tags) }
-    it { should escape(%(unicode \342\200\250 newline).force_encoding(Encoding::UTF_8).encode!).to %(unicode &#x2028; newline) }
-    it { should escape(%(unicode \342\200\251 newline).force_encoding(Encoding::UTF_8).encode!).to %(unicode &#x2029; newline) }
+    it { is_expected.to escape(nil).to '' }
+    it { is_expected.to escape(%(This "thing" is really\n netos')).to %(This \\"thing\\" is really\\n netos\\') }
+    it { is_expected.to escape(%(backslash\\test)).to %(backslash\\\\test) }
+    it { is_expected.to escape(%(dont </close> tags)).to %(dont <\\/close> tags) }
+    it { is_expected.to escape(%(unicode \342\200\250 newline).force_encoding(Encoding::UTF_8).encode!).to %(unicode &#x2028; newline) }
+    it { is_expected.to escape(%(unicode \342\200\251 newline).force_encoding(Encoding::UTF_8).encode!).to %(unicode &#x2029; newline) }
 
     it 'works with symbols' do
       expect(subject).to escape(:dimension1).to 'dimension1'
     end
-
   end
-
-end
\ No newline at end of file
+end
diff --git a/spec/tracker/tracker_spec.rb b/spec/tracker/tracker_spec.rb
index 664e6c1..930b883 100644
--- a/spec/tracker/tracker_spec.rb
+++ b/spec/tracker/tracker_spec.rb
@@ -1,7 +1,8 @@
 # frozen_string_literal: true
+
 class DummyHandler < Rack::Tracker::Handler
   def render
-    Tilt.new( File.join( File.dirname(__FILE__), '../fixtures/dummy.erb') ).render(self)
+    Tilt.new(File.join(File.dirname(__FILE__), '../fixtures/dummy.erb')).render(self)
   end
 
   def dummy_alert
@@ -16,7 +17,7 @@ class BodyHandler < DummyHandler
 RSpec.describe Rack::Tracker do
   def app
     Rack::Builder.new do
-      use Rack::Session::Cookie, secret: "FOO"
+      use Rack::Session::Cookie, secret: 'FOO'
 
       use Rack::Tracker do
         handler DummyHandler, { foo: 'head' }
@@ -24,23 +25,23 @@ def app
         handler DummyHandler, { foo: 'I am evil', DO_NOT_RESPECT_DNT_HEADER: true }
       end
 
-      run lambda {|env|
+      run lambda { |env|
         request = Rack::Request.new(env)
         case request.path
-          when '/' then
-            [200, {'Content-Type' => 'application/html'}, ['<head>Hello world</head>']]
-          when '/body' then
-            [200, {'Content-Type' => 'application/html'}, ['<body>bob here</body>']]
-          when '/body-head' then
-            [200, {'Content-Type' => 'application/html'}, ['<head></head><body></body>']]
-          when '/test.xml' then
-            [200, {'Content-Type' => 'application/xml'}, ['Xml here']]
-          when '/redirect' then
-            [302, {'Content-Type' => 'application/html', 'Location' => '/'}, ['<body>redirection</body>']]
-          when '/moved' then
-            [301, {'Content-Type' => 'application/html', 'Location' => '/redirect'}, ['<body>redirection</body>']]
-          else
-            [404, 'Nothing here']
+        when '/' then
+          [200, { 'Content-Type' => 'application/html' }, ['<head>Hello world</head>']]
+        when '/body' then
+          [200, { 'Content-Type' => 'application/html' }, ['<body>bob here</body>']]
+        when '/body-head' then
+          [200, { 'Content-Type' => 'application/html' }, ['<head></head><body></body>']]
+        when '/test.xml' then
+          [200, { 'Content-Type' => 'application/xml' }, ['Xml here']]
+        when '/redirect' then
+          [302, { 'Content-Type' => 'application/html', 'Location' => '/' }, ['<body>redirection</body>']]
+        when '/moved' then
+          [301, { 'Content-Type' => 'application/html', 'Location' => '/redirect' }, ['<body>redirection</body>']]
+        else
+          [404, 'Nothing here']
         end
       }
     end
@@ -56,16 +57,16 @@ def app
     it 'will pass options to the Handler' do
       get '/'
       expect(last_response.body).to include("console.log('head');")
-      expect(last_response.body).to_not include("console.log('body');")
+      expect(last_response.body).not_to include("console.log('body');")
     end
 
     it 'injects custom variables that was directly assigned' do
-      get '/', {}, {'tracker' => { 'dummy' => 'foo bar'}}
+      get '/', session: { 'tracker' => { 'dummy' => 'foo bar' } }
       expect(last_response.body).to include("alert('foo bar');")
     end
 
     it 'injects custom variables that lives in the session' do
-      get '/', {}, {'rack.session' => {'tracker' => { 'dummy' => 'bar foo'}}}
+      get '/', session: { 'rack.session' => { 'tracker' => { 'dummy' => 'bar foo' } } }
       expect(last_response.body).to include("alert('bar foo');")
     end
   end
@@ -74,7 +75,7 @@ def app
     it 'will not inject the body handler code' do
       get '/body'
       expect(last_response.body).to include("console.log('body');")
-      expect(last_response.body).to_not include("console.log('head');")
+      expect(last_response.body).not_to include("console.log('head');")
     end
   end
 
@@ -88,13 +89,13 @@ def app
 
   describe 'when a redirect' do
     it 'will keep the tracker attributes and show them on the new location' do
-      get '/redirect', {}, { 'tracker' => { 'dummy' => 'Keep this!' } }
+      get '/redirect', session: { 'tracker' => { 'dummy' => 'Keep this!' } }
       follow_redirect!
       expect(last_response.body).to include("alert('Keep this!');")
     end
 
     it 'will keep the tracker attributes over multiple redirects' do
-      get '/moved', {}, { 'tracker' => { 'dummy' => 'Keep this twice!' } }
+      get '/moved', session: { 'tracker' => { 'dummy' => 'Keep this twice!' } }
       follow_redirect!
       expect(last_response.body).to include("alert('Keep this twice!');")
     end
@@ -104,21 +105,21 @@ def app
     it 'will not inject the handler code' do
       get '/test.xml'
 
-      expect(last_response.body).to_not include("alert('this is a dummy class');")
+      expect(last_response.body).not_to include("alert('this is a dummy class');")
     end
   end
 
   describe 'do not track' do
     context 'DNT header set to 1' do
       it 'will not inject any tracker' do
-        get '/', {}, {'HTTP_DNT' => 1 }
+        get '/', session: { 'HTTP_DNT' => 1 }
 
         # the DummyHandler respects the DNT
-        expect(last_response.body).to_not include("console.log('head');")
+        expect(last_response.body).not_to include("console.log('head');")
       end
 
       it 'will allow the DO_NOT_RESPECT_DNT_HEADER overwrite' do
-        get '/', {}, {'HTTP_DNT' => 1 }
+        get '/', session: { 'HTTP_DNT' => 1 }
 
         # the EvilHandler respects the DNT
         expect(last_response.body).to include("console.log('I am evil');")
@@ -127,7 +128,7 @@ def app
 
     context 'DNT header set to 0' do
       it 'injects all trackers' do
-        get '/', {}, {'HTTP_DNT' => 0 }
+        get '/', session: { 'HTTP_DNT' => 0 }
         expect(last_response.body).to include("console.log('head');")
         expect(last_response.body).to include("console.log('I am evil');")
       end
@@ -140,6 +141,5 @@ def app
         expect(last_response.body).to include("console.log('I am evil');")
       end
     end
-
   end
 end