diff --git a/.rubocop.yml b/.rubocop.yml
new file mode 100644
index 0000000..7de53eb
--- /dev/null
+++ b/.rubocop.yml
@@ -0,0 +1,102 @@
+AllCops:
+  DisabledByDefault: false
+  TargetRubyVersion: 2.3.0
+
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyleAlignWith, AutoCorrect, Severity.
+# SupportedStylesAlignWith: keyword, variable, start_of_line
+Layout/EndAlignment:
+  EnforcedStyleAlignWith: variable
+
+# Offense count: 2
+Lint/HandleExceptions:
+  Exclude:
+    - 'lib/capybara/poltergeist/client.rb'
+    - 'lib/capybara/poltergeist/driver.rb'
+
+# Offense count: 8
+Metrics/AbcSize:
+  Max: 36
+
+# Configuration parameters: CountComments, ExcludedMethods.
+Metrics/BlockLength:
+  Max: 1217
+
+# Configuration parameters: CountComments.
+Metrics/ClassLength:
+  Max: 383
+
+Metrics/CyclomaticComplexity:
+  Max: 12
+
+# Configuration parameters: CountComments.
+Metrics/MethodLength:
+  Max: 28
+
+# Configuration parameters: CountComments.
+Metrics/ModuleLength:
+  Max: 1219
+
+Metrics/PerceivedComplexity:
+  Max: 12
+
+# Configuration parameters: AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
+# URISchemes: http, https
+Metrics/LineLength:
+  Max: 172
+
+Naming/AccessorMethodName:
+  Exclude:
+    - 'lib/capybara/poltergeist/browser.rb'
+    - 'spec/**/*'
+
+Naming/MemoizedInstanceVariableName:
+  Exclude:
+    - 'lib/capybara/poltergeist/inspector.rb'
+
+Naming/UncommunicativeMethodParamName:
+  AllowedNames: io, id, to, by, on, in, at, x, y, ip
+
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: prefer_alias, prefer_alias_method
+Style/Alias:
+  Exclude:
+    - 'lib/capybara/poltergeist/driver.rb'
+    - 'lib/capybara/poltergeist/node.rb'
+
+# Cop supports --auto-correct.
+# Configuration parameters: AutoCorrect, EnforcedStyle.
+# SupportedStyles: nested, compact
+Style/ClassAndModuleChildren:
+  Enabled: false
+
+Style/Documentation:
+  Enabled: false
+
+Style/DoubleNegation:
+  Exclude:
+    - 'lib/capybara/poltergeist/browser.rb'
+    - 'lib/capybara/poltergeist/node.rb'
+
+# Cop supports --auto-correct.
+# Configuration parameters: Strict.
+Style/NumericLiterals:
+  MinDigits: 6
+
+# Cop supports --auto-correct.
+Style/RescueModifier:
+  Exclude:
+    - 'lib/capybara/poltergeist/driver.rb'
+    - 'spec/**/*'
+
+# Cop supports --auto-correct.
+# Configuration parameters: AllowAsExpressionSeparator.
+Style/Semicolon:
+  AllowAsExpressionSeparator: true
+
+# Cop supports --auto-correct.
+# Configuration parameters: .
+# SupportedStyles: use_perl_names, use_english_names
+Style/SpecialGlobalVars:
+  Enabled: false
diff --git a/Gemfile b/Gemfile
index d53dec2..682fca5 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 gemspec
@@ -5,7 +7,7 @@ gemspec
 gem 'puma'
 
 platforms :rbx do
-  gem 'rubysl'
-  gem 'racc'
   gem 'json'
+  gem 'racc'
+  gem 'rubysl'
 end
diff --git a/Guardfile b/Guardfile
index 8754c7a..1889096 100644
--- a/Guardfile
+++ b/Guardfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 guard 'coffeescript', input: 'lib/capybara/poltergeist/client',
                       output: 'lib/capybara/poltergeist/client/compiled',
                       bare: true
diff --git a/Rakefile b/Rakefile
index e630a4e..0c9c956 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'bundler/setup'
 require 'rspec/core/rake_task'
 
@@ -5,7 +7,7 @@ require 'capybara/poltergeist/version'
 require 'coffee-script'
 
 RSpec::Core::RakeTask.new('test')
-task default: [:compile, :test]
+task default: %i[compile test]
 
 task(:autocompile) { system 'guard' }
 
diff --git a/config.ru b/config.ru
index 51f963b..3b9a1f2 100644
--- a/config.ru
+++ b/config.ru
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'bundler/setup'
 require File.expand_path('spec/support/test_app')
 run TestApp
diff --git a/lib/capybara/poltergeist.rb b/lib/capybara/poltergeist.rb
index f4eb70b..723ff1f 100644
--- a/lib/capybara/poltergeist.rb
+++ b/lib/capybara/poltergeist.rb
@@ -1,10 +1,5 @@
 # frozen_string_literal: true
 
-if RUBY_VERSION < "1.9.2"
-  raise "This version of Capybara/Poltergeist does not support Ruby versions " \
-        "less than 1.9.2."
-end
-
 require 'capybara'
 
 module Capybara
diff --git a/lib/capybara/poltergeist/browser.rb b/lib/capybara/poltergeist/browser.rb
index 203b29c..30f40a0 100644
--- a/lib/capybara/poltergeist/browser.rb
+++ b/lib/capybara/poltergeist/browser.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-require "capybara/poltergeist/errors"
-require "capybara/poltergeist/command"
+require 'capybara/poltergeist/errors'
+require 'capybara/poltergeist/command'
 require 'json'
 require 'time'
 
@@ -15,8 +15,8 @@ module Capybara::Poltergeist
       'Poltergeist.NoSuchWindowError' => NoSuchWindowError,
       'Poltergeist.ScriptTimeoutError' => ScriptTimeoutError,
       'Poltergeist.UnsupportedFeature' => UnsupportedFeature,
-      'Poltergeist.KeyError' => KeyError,
-    }
+      'Poltergeist.KeyError' => KeyError
+    }.freeze
 
     attr_reader :server, :client, :logger
 
@@ -144,7 +144,7 @@ module Capybara::Poltergeist
       command 'execute', script, *args
     end
 
-    def within_frame(handle, &block)
+    def within_frame(handle)
       if handle.is_a?(Capybara::Node::Base)
         command 'push_frame', [handle.native.page_id, handle.native.id]
       else
@@ -192,10 +192,10 @@ module Capybara::Poltergeist
 
       handle = command 'window_handle', locator
       raise NoSuchWindowError unless handle
-      return handle
+      handle
     end
 
-    def within_window(locator, &block)
+    def within_window(locator)
       original = window_handle
       handle = find_window_handle(locator)
       switch_to_window(handle)
@@ -204,15 +204,15 @@ module Capybara::Poltergeist
       switch_to_window(original)
     end
 
-    def click(page_id, id, keys=[], offset={})
+    def click(page_id, id, keys = [], offset = {})
       command 'click', page_id, id, keys, offset
     end
 
-    def right_click(page_id, id, keys=[], offset={})
+    def right_click(page_id, id, keys = [], offset = {})
       command 'right_click', page_id, id, keys, offset
     end
 
-    def double_click(page_id, id, keys=[], offset={})
+    def double_click(page_id, id, keys = [], offset = {})
       command 'double_click', page_id, id, keys, offset
     end
 
@@ -313,7 +313,7 @@ module Capybara::Poltergeist
       command 'add_headers', headers
     end
 
-    def add_header(header, options={})
+    def add_header(header, options = {})
       command 'add_header', header, options
     end
 
@@ -326,10 +326,7 @@ module Capybara::Poltergeist
     end
 
     def set_cookie(cookie)
-      if cookie[:expires]
-        cookie[:expires] = cookie[:expires].to_i * 1000
-      end
-
+      cookie[:expires] = cookie[:expires].to_i * 1000 if cookie[:expires]
       command 'set_cookie', cookie
     end
 
@@ -389,11 +386,11 @@ module Capybara::Poltergeist
       response = server.send(cmd)
       log response
 
-      json = JSON.load(response)
+      json = JSON.parse(response)
 
       if json['error']
         klass = ERROR_MAPPINGS[json['error']['name']] || BrowserError
-        raise klass.new(json['error'])
+        raise klass, json['error']
       else
         json['response']
       end
@@ -443,14 +440,13 @@ module Capybara::Poltergeist
     private
 
     def log(message)
-      logger.puts message if logger
+      logger&.puts message
     end
 
     def check_render_options!(options)
-      if !!options[:full] && options.has_key?(:selector)
-        warn "Ignoring :selector in #render since :full => true was given at #{caller.first}"
-        options.delete(:selector)
-      end
+      return unless options[:full] && options.key?(:selector)
+      warn "Ignoring :selector in #render since :full => true was given at #{caller(1..1).first}"
+      options.delete(:selector)
     end
 
     KEY_ALIASES = {
@@ -463,7 +459,7 @@ module Capybara::Poltergeist
       divide:    'numpad/',
       subtract:  'numpad-',
       decimal:   'numpad.'
-    }
+    }.freeze
 
     def normalize_keys(keys)
       keys.map do |key_desc|
@@ -474,9 +470,9 @@ module Capybara::Poltergeist
           # [:Ctrl, :Left] => { modifier: "ctrl", key: 'Left' }
           # [:Ctrl, :Shift, :Left] => { modifier: "ctrl,shift", key: 'Left' }
           # [:Ctrl, :Left, :Left] => { modifier: "ctrl", key: [:Left, :Left] }
-          _keys = key_desc.chunk {|k| k.is_a?(Symbol) && %w(shift ctrl control alt meta command).include?(k.to_s.downcase) }
-          modifiers = if _keys.peek[0]
-            _keys.next[1].map do |k|
+          chunked_keys = key_desc.chunk { |k| k.is_a?(Symbol) && %w[shift ctrl control alt meta command].include?(k.to_s.downcase) }
+          modifiers = if chunked_keys.peek[0]
+            chunked_keys.next[1].map do |k|
               k = k.to_s.downcase
               k = 'ctrl' if k == 'control'
               k = 'meta' if k == 'command'
@@ -485,15 +481,15 @@ module Capybara::Poltergeist
           else
             ''
           end
-          letters = normalize_keys(_keys.next[1].map {|k| k.is_a?(String) ? k.upcase : k })
+          letters = normalize_keys(chunked_keys.next[1].map { |k| k.is_a?(String) ? k.upcase : k })
           { modifier: modifiers, keys: letters }
         when Symbol
           # Return a known sequence for PhantomJS
           key = KEY_ALIASES.fetch(key_desc, key_desc)
-          if match = key.to_s.match(/numpad(.)/)
+          if (match = key.to_s.match(/numpad(.)/))
             res = { keys: match[1], modifier: 'keypad' }
           elsif key !~ /^[A-Z]/
-            key = key.to_s.split('_').map{ |e| e.capitalize }.join
+            key = key.to_s.split('_').map(&:capitalize).join
           end
           res || { key: key }
         when String
diff --git a/lib/capybara/poltergeist/client.rb b/lib/capybara/poltergeist/client.rb
index c23d55e..e3b749a 100644
--- a/lib/capybara/poltergeist/client.rb
+++ b/lib/capybara/poltergeist/client.rb
@@ -1,13 +1,12 @@
 # frozen_string_literal: true
 
-require "timeout"
-require "capybara/poltergeist/utility"
+require 'capybara/poltergeist/utility'
 require 'cliver'
 
 module Capybara::Poltergeist
   class Client
-    PHANTOMJS_SCRIPT  = File.expand_path('../client/compiled/main.js', __FILE__)
-    PHANTOMJS_VERSION = ['>= 1.8.1', '< 3.0']
+    PHANTOMJS_SCRIPT  = File.expand_path('client/compiled/main.js', __dir__)
+    PHANTOMJS_VERSION = ['>= 1.8.1', '< 3.0'].freeze
     PHANTOMJS_NAME    = 'phantomjs'
 
     KILL_TIMEOUT = 2 # seconds
@@ -32,11 +31,10 @@ module Capybara::Poltergeist
             start = Time.now
             while Process.wait(pid, Process::WNOHANG).nil?
               sleep 0.05
-              if (Time.now - start) > KILL_TIMEOUT
-                Process.kill('KILL', pid)
-                Process.wait(pid)
-                break
-              end
+              next unless (Time.now - start) > KILL_TIMEOUT
+              Process.kill('KILL', pid)
+              Process.wait(pid)
+              break
             end
           end
         rescue Errno::ESRCH, Errno::ECHILD
@@ -49,8 +47,8 @@ module Capybara::Poltergeist
 
     def initialize(server, options = {})
       @server            = server
-      @path              = Cliver::detect((options[:path] || PHANTOMJS_NAME), *['>=2.1.0', '< 3.0'])
-      @path            ||= Cliver::detect!((options[:path] || PHANTOMJS_NAME), *PHANTOMJS_VERSION).tap do
+      @path              = Cliver.detect((options[:path] || PHANTOMJS_NAME), '>=2.1.0', '< 3.0')
+      @path            ||= Cliver.detect!((options[:path] || PHANTOMJS_NAME), *PHANTOMJS_VERSION).tap do
         warn "You're running an old version of PhantomJS, update to >= 2.1.1 for a better experience."
       end
 
@@ -61,13 +59,13 @@ module Capybara::Poltergeist
 
     def start
       @read_io, @write_io = IO.pipe
-      @out_thread = Thread.new {
-        while !@read_io.eof? && data = @read_io.readpartial(1024)
+      @out_thread = Thread.new do
+        while !@read_io.eof? && (data = @read_io.readpartial(1024))
           @phantomjs_logger.write(data)
         end
-      }
+      end
 
-      process_options = {in: File::NULL}
+      process_options = { in: File::NULL }
       process_options[:pgroup] = true unless Capybara::Poltergeist.windows?
       process_options[:out] = @write_io if Capybara::Poltergeist.mri?
 
@@ -78,12 +76,11 @@ module Capybara::Poltergeist
     end
 
     def stop
-      if pid
-        kill_phantomjs
-        @out_thread.kill
-        close_io
-        ObjectSpace.undefine_finalizer(self)
-      end
+      return unless pid
+      kill_phantomjs
+      @out_thread.kill
+      close_io
+      ObjectSpace.undefine_finalizer(self)
     end
 
     def restart
diff --git a/lib/capybara/poltergeist/command.rb b/lib/capybara/poltergeist/command.rb
index 35a3ffd..ab46f2b 100644
--- a/lib/capybara/poltergeist/command.rb
+++ b/lib/capybara/poltergeist/command.rb
@@ -15,7 +15,7 @@ module Capybara::Poltergeist
     end
 
     def message
-      JSON.dump({ 'id' => @id, 'name' => @name, 'args' => @args })
+      JSON.dump('id' => @id, 'name' => @name, 'args' => @args)
     end
   end
 end
diff --git a/lib/capybara/poltergeist/driver.rb b/lib/capybara/poltergeist/driver.rb
index c1a1775..c9bd412 100644
--- a/lib/capybara/poltergeist/driver.rb
+++ b/lib/capybara/poltergeist/driver.rb
@@ -45,11 +45,10 @@ module Capybara::Poltergeist
 
     def client
       @client ||= Client.start(server,
-        :path              => options[:phantomjs],
-        :window_size       => options[:window_size],
-        :phantomjs_options => phantomjs_options,
-        :phantomjs_logger  => phantomjs_logger
-      )
+                               path:              options[:phantomjs],
+                               window_size:       options[:window_size],
+                               phantomjs_options: phantomjs_options,
+                               phantomjs_logger:  phantomjs_logger)
     end
 
     def phantomjs_options
@@ -58,9 +57,9 @@ module Capybara::Poltergeist
       # PhantomJS defaults to only using SSLv3, which since POODLE (Oct 2014)
       # many sites have dropped from their supported protocols (eg PayPal,
       # Braintree).
-      list += ["--ignore-ssl-errors=yes"] unless list.grep(/ignore-ssl-errors/).any?
-      list += ["--ssl-protocol=TLSv1"] unless list.grep(/ssl-protocol/).any?
-      list += ["--remote-debugger-port=#{inspector.port}", "--remote-debugger-autorun=yes"] if inspector
+      list += ['--ignore-ssl-errors=yes'] unless list.grep(/ignore-ssl-errors/).any?
+      list += ['--ssl-protocol=TLSv1'] unless list.grep(/ssl-protocol/).any?
+      list += ["--remote-debugger-port=#{inspector.port}", '--remote-debugger-autorun=yes'] if inspector
       list
     end
 
@@ -154,17 +153,17 @@ module Capybara::Poltergeist
     end
 
     def evaluate_script(script, *args)
-      result = browser.evaluate(script, *args.map { |arg| arg.is_a?(Capybara::Poltergeist::Node) ?  arg.native : arg})
+      result = browser.evaluate(script, *native_args(args))
       unwrap_script_result(result)
     end
 
     def evaluate_async_script(script, *args)
-      result = browser.evaluate_async(script, session_wait_time, *args.map { |arg| arg.is_a?(Capybara::Poltergeist::Node) ?  arg.native : arg})
+      result = browser.evaluate_async(script, session_wait_time, *native_args(args))
       unwrap_script_result(result)
     end
 
     def execute_script(script, *args)
-      browser.execute(script, *args.map { |arg| arg.is_a?(Capybara::Poltergeist::Node) ?  arg.native : arg})
+      browser.execute(script, *native_args(args))
       nil
     end
 
@@ -261,7 +260,7 @@ module Capybara::Poltergeist
       browser.clear_network_traffic
     end
 
-    def set_proxy(ip, port, type = "http", user = nil, password = nil)
+    def set_proxy(ip, port, type = 'http', user = nil, password = nil)
       browser.set_proxy(ip, port, type, user, password)
     end
 
@@ -296,7 +295,7 @@ module Capybara::Poltergeist
         if @started
           URI.parse(browser.current_url).host
         else
-          URI.parse(default_cookie_host).host || "127.0.0.1"
+          URI.parse(default_cookie_host).host || '127.0.0.1'
         end
       end
 
@@ -338,8 +337,8 @@ module Capybara::Poltergeist
         inspector.open(scheme)
         pause
       else
-        raise Error, "To use the remote debugging, you have to launch the driver " \
-                     "with `:inspector => true` configuration option"
+        raise Error, 'To use the remote debugging, you have to launch the driver ' \
+                     'with `:inspector => true` configuration option'
       end
     end
 
@@ -358,12 +357,13 @@ module Capybara::Poltergeist
       old_trap = trap('SIGCONT') { signal = true; STDERR.puts "\nSignal SIGCONT received" }
       keyboard = IO.select([read], nil, nil, 1) until keyboard || signal # wait for data on STDIN or signal SIGCONT received
 
-      begin
-        input = read.read_nonblock(80) # clear out the read buffer
-        puts unless input && input =~ /\n\z/
-      rescue EOFError, IO::WaitReadable # Ignore problems reading from STDIN.
-      end unless signal
-
+      unless signal
+        begin
+          input = read.read_nonblock(80) # clear out the read buffer
+          puts unless input&.end_with?("\n")
+        rescue EOFError, IO::WaitReadable # Ignore problems reading from STDIN.
+        end
+      end
     ensure
       trap('SIGCONT', old_trap) # Restore the previous signal handler, if there was one.
       STDERR.puts 'Continuing'
@@ -416,8 +416,12 @@ module Capybara::Poltergeist
 
     private
 
+    def native_args(args)
+      args.map { |arg| arg.is_a?(Capybara::Poltergeist::Node) ? arg.native : arg }
+    end
+
     def screen_size
-      options[:screen_size] || [1366,768]
+      options[:screen_size] || [1366, 768]
     end
 
     def find_modal(options)
diff --git a/lib/capybara/poltergeist/errors.rb b/lib/capybara/poltergeist/errors.rb
index 4dda584..bb4f73b 100644
--- a/lib/capybara/poltergeist/errors.rb
+++ b/lib/capybara/poltergeist/errors.rb
@@ -36,9 +36,9 @@ module Capybara
       end
 
       def message
-        "There was an error inside the PhantomJS portion of Poltergeist. " \
-          "If this is the error returned, and not the cause of a more detailed error response, " \
-          "this is probably a bug, so please report it. " \
+        'There was an error inside the PhantomJS portion of Poltergeist. ' \
+          'If this is the error returned, and not the cause of a more detailed error response, ' \
+          'this is probably a bug, so please report it. ' \
           "\n\n#{name}: #{error_parameters}"
       end
     end
@@ -49,10 +49,10 @@ module Capybara
       end
 
       def message
-        "One or more errors were raised in the Javascript code on the page. " \
+        'One or more errors were raised in the Javascript code on the page. ' \
           "If you don't care about these errors, you can ignore them by " \
-          "setting js_errors: false in your Poltergeist configuration (see " \
-          "documentation for details)." \
+          'setting js_errors: false in your Poltergeist configuration (see ' \
+          'documentation for details).' \
           "\n\n#{javascript_errors.map(&:to_s).join("\n")}"
       end
     end
@@ -93,7 +93,7 @@ module Capybara
       end
 
       def message
-        "The browser raised a syntax error while trying to evaluate " \
+        'The browser raised a syntax error while trying to evaluate ' \
           "#{method} selector #{selector.inspect}"
       end
     end
@@ -109,11 +109,11 @@ module Capybara
 
     class ObsoleteNode < NodeError
       def message
-        "The element you are trying to interact with is either not part of the DOM, or is " \
-          "not currently visible on the page (perhaps display: none is set). " \
+        'The element you are trying to interact with is either not part of the DOM, or is ' \
+          'not currently visible on the page (perhaps display: none is set). ' \
           "It's possible the element has been replaced by another element and you meant to interact with " \
           "the new element. If so you need to do a new 'find' in order to get a reference to the " \
-          "new element."
+          'new element.'
       end
     end
 
@@ -127,7 +127,7 @@ module Capybara
       end
 
       def version
-        response['args'][1].values_at(*%w(major minor patch)).join '.'
+        response['args'][1].values_at('major', 'minor', 'patch').join '.'
       end
 
       def message
@@ -151,14 +151,14 @@ module Capybara
       def message
         "Firing a #{name} at co-ordinates [#{position.join(', ')}] failed. Poltergeist detected " \
           "another element with CSS selector '#{selector}' at this position. " \
-          "It may be overlapping the element you are trying to interact with. " \
+          'It may be overlapping the element you are trying to interact with. ' \
           "If you don't care about overlapping elements, try using node.trigger('#{name}')."
       end
     end
 
     class KeyError < ::ArgumentError
       def initialize(response)
-        super(response["args"].first)
+        super(response['args'].first)
       end
     end
 
@@ -169,20 +169,19 @@ module Capybara
 
       def message
         "Timed out waiting for response to #{@message}. It's possible that this happened " \
-          "because something took a very long time (for example a page load was slow). " \
-          "If so, setting the Poltergeist :timeout option to a higher value will help " \
-          "(see the docs for details). If increasing the timeout does not help, this is " \
-          "probably a bug in Poltergeist - please report it to the issue tracker."
+          'because something took a very long time (for example a page load was slow). ' \
+          'If so, setting the Poltergeist :timeout option to a higher value will help ' \
+          '(see the docs for details). If increasing the timeout does not help, this is ' \
+          'probably a bug in Poltergeist - please report it to the issue tracker.'
       end
     end
 
     class ScriptTimeoutError < Error
       def message
-        "Timed out waiting for evaluated script to resturn a value"
+        'Timed out waiting for evaluated script to resturn a value'
       end
     end
 
-
     class DeadClient < Error
       def initialize(message)
         @message = message
@@ -195,10 +194,10 @@ module Capybara
 
     class PhantomJSTooOld < Error
       def self.===(other)
-        if Cliver::Dependency::VersionMismatch === other
-          warn "#{name} exception has been deprecated in favor of using the " +
-               "cliver gem for command-line dependency detection. Please " +
-               "handle Cliver::Dependency::VersionMismatch instead."
+        if other.is_a? Cliver::Dependency::VersionMismatch
+          warn "#{name} exception has been deprecated in favor of using the " \
+               'cliver gem for command-line dependency detection. Please ' \
+               'handle Cliver::Dependency::VersionMismatch instead.'
           true
         else
           super
@@ -208,10 +207,10 @@ module Capybara
 
     class PhantomJSFailed < Error
       def self.===(other)
-        if Cliver::Dependency::NotMet === other
-          warn "#{name} exception has been deprecated in favor of using the " +
-               "cliver gem for command-line dependency detection. Please " +
-               "handle Cliver::Dependency::NotMet instead."
+        if other.is_a? Cliver::Dependency::NotMet
+          warn "#{name} exception has been deprecated in favor of using the " \
+               'cliver gem for command-line dependency detection. Please ' \
+               'handle Cliver::Dependency::NotMet instead.'
           true
         else
           super
diff --git a/lib/capybara/poltergeist/inspector.rb b/lib/capybara/poltergeist/inspector.rb
index 7896f11..5e15034 100644
--- a/lib/capybara/poltergeist/inspector.rb
+++ b/lib/capybara/poltergeist/inspector.rb
@@ -2,7 +2,7 @@
 
 module Capybara::Poltergeist
   class Inspector
-    BROWSERS     = %w(chromium chromium-browser google-chrome open)
+    BROWSERS     = %w[chromium chromium-browser google-chrome open].freeze
     DEFAULT_PORT = 9664
 
     def self.detect_browser
@@ -30,19 +30,19 @@ module Capybara::Poltergeist
       else
         raise Error, "Could not find a browser executable to open #{url(scheme)}. " \
                      "You can specify one manually using e.g. `:inspector => 'chromium'` " \
-                     "as a configuration option for Poltergeist."
+                     'as a configuration option for Poltergeist.'
       end
     end
 
     def self.browser_binary_exists?(browser)
       exts = ENV['PATHEXT'] ? ENV['PATHEXT'].split(';') : ['']
       ENV['PATH'].split(File::PATH_SEPARATOR).each do |path|
-        exts.each { |ext|
+        exts.each do |ext|
           exe = "#{path}#{File::SEPARATOR}#{browser}#{ext}"
           return exe if File.executable? exe
-        }
+        end
       end
-      return nil
+      nil
     end
   end
 end
diff --git a/lib/capybara/poltergeist/network_traffic/response.rb b/lib/capybara/poltergeist/network_traffic/response.rb
index 33b8c04..875fa61 100644
--- a/lib/capybara/poltergeist/network_traffic/response.rb
+++ b/lib/capybara/poltergeist/network_traffic/response.rb
@@ -39,4 +39,3 @@ module Capybara::Poltergeist::NetworkTraffic
     end
   end
 end
-
diff --git a/lib/capybara/poltergeist/node.rb b/lib/capybara/poltergeist/node.rb
index eb9405b..b1c2381 100644
--- a/lib/capybara/poltergeist/node.rb
+++ b/lib/capybara/poltergeist/node.rb
@@ -53,8 +53,8 @@ module Capybara::Poltergeist
         filter_text command(:visible_text)
       else
         command(:visible_text).to_s
-                              .gsub(/\A[[:space:]&&[^\u00a0]]+/, "")
-                              .gsub(/[[:space:]&&[^\u00a0]]+\z/, "")
+                              .gsub(/\A[[:space:]&&[^\u00a0]]+/, '')
+                              .gsub(/[[:space:]&&[^\u00a0]]+\z/, '')
                               .gsub(/\n+/, "\n")
                               .tr("\u00a0", ' ')
       end
@@ -67,10 +67,9 @@ module Capybara::Poltergeist
     def [](name)
       # Although the attribute matters, the property is consistent. Return that in
       # preference to the attribute for links and images.
-      if (tag_name == 'img' and name == 'src') or (tag_name == 'a' and name == 'href' )
-         #if attribute exists get the property
-         value = command(:attribute, name) && command(:property, name)
-         return value
+      if ((tag_name == 'img') && (name == 'src')) || ((tag_name == 'a') && (name == 'href'))
+        # if attribute exists get the property
+        return command(:attribute, name) && command(:property, name)
       end
 
       value = property(name)
@@ -115,8 +114,8 @@ module Capybara::Poltergeist
     end
 
     def unselect_option
-      command(:select, false) or
-      raise(Capybara::UnselectNotAllowed, "Cannot unselect option from single select box.")
+      command(:select, false) ||
+        raise(Capybara::UnselectNotAllowed, 'Cannot unselect option from single select box.')
     end
 
     def tag_name
@@ -139,15 +138,15 @@ module Capybara::Poltergeist
       command :disabled?
     end
 
-    def click(keys=[], offset={})
+    def click(keys = [], offset = {})
       command :click, keys, offset
     end
 
-    def right_click(keys=[], offset={})
+    def right_click(keys = [], offset = {})
       command :right_click, keys, offset
     end
 
-    def double_click(keys=[], offset={})
+    def double_click(keys = [], offset = {})
       command :double_click, keys, offset
     end
 
@@ -187,19 +186,19 @@ module Capybara::Poltergeist
 
     # @api private
     def as_json(*)
-      { ELEMENT: {page_id: @page_id, id: @id} }
+      { ELEMENT: { page_id: @page_id, id: @id } }
     end
 
     private
 
-    def filter_text(text, visible = true)
+    def filter_text(text)
       if Capybara::VERSION.to_f < 3
         Capybara::Helpers.normalize_whitespace(text.to_s)
       else
         text.gsub(/[\u200b\u200e\u200f]/, '')
             .gsub(/[\ \n\f\t\v\u2028\u2029]+/, ' ')
-            .gsub(/\A[[:space:]&&[^\u00a0]]+/, "")
-            .gsub(/[[:space:]&&[^\u00a0]]+\z/, "")
+            .gsub(/\A[[:space:]&&[^\u00a0]]+/, '')
+            .gsub(/[[:space:]&&[^\u00a0]]+\z/, '')
             .tr("\u00a0", ' ')
       end
     end
diff --git a/lib/capybara/poltergeist/server.rb b/lib/capybara/poltergeist/server.rb
index a60fa57..9cc021d 100644
--- a/lib/capybara/poltergeist/server.rb
+++ b/lib/capybara/poltergeist/server.rb
@@ -42,7 +42,7 @@ module Capybara::Poltergeist
         command.args.push(timeout) # set the client set visit timeout parameter
         receive_timeout = timeout + 5 # Add a couple of seconds to let the client timeout first
       end
-      @socket.send(command.id, command.message, receive_timeout) or raise DeadClient.new(command.message)
+      @socket.send(command.id, command.message, receive_timeout) || raise(DeadClient, command.message)
     end
   end
 end
diff --git a/lib/capybara/poltergeist/utility.rb b/lib/capybara/poltergeist/utility.rb
index 02f5ef1..3885f21 100644
--- a/lib/capybara/poltergeist/utility.rb
+++ b/lib/capybara/poltergeist/utility.rb
@@ -4,11 +4,11 @@ module Capybara
   module Poltergeist
     class << self
       def windows?
-        RbConfig::CONFIG["host_os"] =~ /mingw|mswin|cygwin/
+        RbConfig::CONFIG['host_os'] =~ /mingw|mswin|cygwin/
       end
 
       def mri?
-        defined?(RUBY_ENGINE) && RUBY_ENGINE == "ruby"
+        defined?(RUBY_ENGINE) && RUBY_ENGINE == 'ruby'
       end
     end
   end
diff --git a/lib/capybara/poltergeist/version.rb b/lib/capybara/poltergeist/version.rb
index c57dc1c..1de6f38 100644
--- a/lib/capybara/poltergeist/version.rb
+++ b/lib/capybara/poltergeist/version.rb
@@ -2,6 +2,6 @@
 
 module Capybara
   module Poltergeist
-    VERSION = "1.18.1"
+    VERSION = '1.18.1'
   end
 end
diff --git a/lib/capybara/poltergeist/web_socket_server.rb b/lib/capybara/poltergeist/web_socket_server.rb
index ff107e2..c862253 100644
--- a/lib/capybara/poltergeist/web_socket_server.rb
+++ b/lib/capybara/poltergeist/web_socket_server.rb
@@ -38,12 +38,9 @@ module Capybara::Poltergeist
           @host = server.addr[2]
         end
       rescue Errno::EADDRINUSE
-        if (Time.now - time) < BIND_TIMEOUT
-          sleep(0.01)
-          retry
-        else
-          raise
-        end
+        raise if (Time.now - time) >= BIND_TIMEOUT
+        sleep(0.01)
+        retry
       end
     end
 
@@ -58,9 +55,9 @@ module Capybara::Poltergeist
       @messages = {}
 
       @driver = ::WebSocket::Driver.server(self)
-      @driver.on(:connect) { |event| @driver.start }
+      @driver.on(:connect) { |_event| @driver.start }
       @driver.on(:message) do |event|
-        command_id = JSON.load(event.data)['command_id']
+        command_id = JSON.parse(event.data)['command_id']
         @messages[command_id] = event.data
       end
     end
@@ -71,15 +68,15 @@ module Capybara::Poltergeist
 
     # Block until the next message is available from the Web Socket.
     # Raises Errno::EWOULDBLOCK if timeout is reached.
-    def receive(cmd_id, receive_timeout=nil)
+    def receive(cmd_id, receive_timeout = nil)
       receive_timeout ||= timeout
       start = Time.now
 
-      until @messages.has_key?(cmd_id)
+      until @messages.key?(cmd_id)
         raise Errno::EWOULDBLOCK if (Time.now - start) >= receive_timeout
         if @receive_mutex.try_lock
           begin
-            IO.select([socket], [], [], receive_timeout) or raise Errno::EWOULDBLOCK
+            IO.select([socket], [], [], receive_timeout) || raise(Errno::EWOULDBLOCK)
             data = socket.recv(RECV_SIZE)
             break if data.empty?
             driver.parse(data)
@@ -94,12 +91,12 @@ module Capybara::Poltergeist
     end
 
     # Send a message and block until there is a response
-    def send(cmd_id, message, accept_timeout=nil)
+    def send(cmd_id, message, accept_timeout = nil)
       accept unless connected?
       driver.text(message)
       receive(cmd_id, accept_timeout)
     rescue Errno::EWOULDBLOCK
-      raise TimeoutError.new(message)
+      raise TimeoutError, message
     end
 
     # Closing sockets separately as `close_read`, `close_write`
diff --git a/poltergeist.gemspec b/poltergeist.gemspec
index 78f5342..cc33684 100644
--- a/poltergeist.gemspec
+++ b/poltergeist.gemspec
@@ -1,4 +1,6 @@
-lib = File.expand_path('../lib/', __FILE__)
+# frozen_string_literal: true
+
+lib = File.expand_path('lib', __dir__)
 $:.unshift lib unless $:.include?(lib)
 
 require 'capybara/poltergeist/version'
@@ -16,23 +18,23 @@ Gem::Specification.new do |s|
                     'PhantomJS.'
   s.license       = 'MIT'
   s.require_paths = ['lib']
-  s.files         = Dir.glob('{lib}/**/*') + %w(LICENSE README.md)
+  s.files         = Dir.glob('{lib}/**/*') + %w[LICENSE README.md]
 
   s.required_ruby_version = '>= 2.3.0'
 
   s.add_runtime_dependency 'capybara',         '>= 2.1', '< 4'
-  s.add_runtime_dependency 'websocket-driver', '>= 0.2.0'
   s.add_runtime_dependency 'cliver',           '~> 0.3.1'
+  s.add_runtime_dependency 'websocket-driver', '>= 0.2.0'
 
+  s.add_development_dependency 'coffee-script', '~> 2.2'
+  s.add_development_dependency 'coffee-script-source', '~>1.12.2'
+  s.add_development_dependency 'erubi' # required by rbx
+  s.add_development_dependency 'guard-coffeescript', '~> 2.0.0'
+  s.add_development_dependency 'image_size',         '~> 1.0'
   s.add_development_dependency 'launchy',            '~> 2.0'
+  s.add_development_dependency 'listen', '~> 3.0.6' # listen is required by guard and listen 3.1.0 requires ruby 2.2+
+  s.add_development_dependency 'pdf-reader', '< 3.0', '>= 1.3.3'
+  s.add_development_dependency 'rake'
   s.add_development_dependency 'rspec',              '~> 3.7'
   s.add_development_dependency 'sinatra',            '<= 3.0'
-  s.add_development_dependency 'rake'
-  s.add_development_dependency 'image_size',         '~> 1.0'
-  s.add_development_dependency 'pdf-reader',         '< 3.0', '>= 1.3.3'
-  s.add_development_dependency 'coffee-script',      '~> 2.2'
-  s.add_development_dependency 'guard-coffeescript', '~> 2.0.0'
-  s.add_development_dependency 'coffee-script-source', '~>1.12.2'
-  s.add_development_dependency 'listen', '~> 3.0.6'  # listen is required by guard and listen 3.1.0 requires ruby 2.2+
-  s.add_development_dependency 'erubi'  # required by rbx
 end
diff --git a/spec/integration/driver_spec.rb b/spec/integration/driver_spec.rb
index 75c89d2..c3340aa 100644
--- a/spec/integration/driver_spec.rb
+++ b/spec/integration/driver_spec.rb
@@ -39,7 +39,7 @@ module Capybara::Poltergeist
 
         expect(File.exist?(file)).to be true
       ensure
-        driver.quit if driver
+        driver&.quit
       end
     end
 
@@ -63,20 +63,20 @@ module Capybara::Poltergeist
       end
 
       it 'is threadsafe in how it captures console.log' do
-        pending("JRuby and Rubinius do not support the :out parameter to Process.spawn, so there is no threadsafe way to redirect output") unless Capybara::Poltergeist.mri?
+        pending('JRuby and Rubinius do not support the :out parameter to Process.spawn, so there is no threadsafe way to redirect output') unless Capybara::Poltergeist.mri?
 
         # Write something to STDOUT right before Process.spawn is called
-        allow(Process).to receive(:spawn).and_wrap_original do |m,*args|
-          STDOUT.puts "1"
-          $stdout.puts "2"
+        allow(Process).to receive(:spawn).and_wrap_original do |m, *args|
+          STDOUT.puts '1'
+          $stdout.puts '2'
           m.call(*args)
         end
 
-        expect {
+        expect do
           session.visit('/poltergeist/console_log')
-        }.to output("1\n2\n").to_stdout_from_any_process
+        end.to output("1\n2\n").to_stdout_from_any_process
 
-        expect(logger.string).not_to match /\d/
+        expect(logger.string).not_to match(/\d/)
       end
     end
 
@@ -118,7 +118,7 @@ module Capybara::Poltergeist
         @session.visit('/')
         @session.current_window.maximize
         expect(@session.current_window.size).to eq([1600, 1200])
-     ensure
+      ensure
         @driver.options.delete(:screen_size)
       end
     end
@@ -142,12 +142,12 @@ module Capybara::Poltergeist
           )
         end
         driver = Capybara::Session.new(:poltergeist_with_custom_window_size, TestApp).driver
-        driver.visit(session_url '/')
+        driver.visit(session_url('/'))
         expect(
           driver.evaluate_script('[window.innerWidth, window.innerHeight]')
         ).to eq([800, 600])
       ensure
-        driver.quit if driver
+        driver&.quit
       end
     end
 
@@ -187,13 +187,13 @@ module Capybara::Poltergeist
         create_screenshot file, selector: '#penultimate'
 
         File.open(file, 'rb') do |f|
-          size = @driver.evaluate_script <<-EOS
+          size = @driver.evaluate_script <<-JS
             function() {
               var ele  = document.getElementById('penultimate');
               var rect = ele.getBoundingClientRect();
               return [rect.width, rect.height];
             }();
-          EOS
+          JS
           expect(ImageSize.new(f.read).size).to eq(size)
         end
       end
@@ -214,7 +214,7 @@ module Capybara::Poltergeist
       it 'resets element positions after' do
         @session.visit('poltergeist/long_page')
         el = @session.find(:css, '#middleish')
-        #make the page scroll an element into view
+        # make the page scroll an element into view
         el.click
         position_script = 'document.querySelector("#middleish").getBoundingClientRect()'
         offset = @session.evaluate_script(position_script)
@@ -251,7 +251,7 @@ module Capybara::Poltergeist
 
       it 'supports rendering the page to file without extension when format is specified' do
         begin
-          file = POLTERGEIST_ROOT + "/spec/tmp/screenshot"
+          file = POLTERGEIST_ROOT + '/spec/tmp/screenshot'
           FileUtils.rm_f file
           @session.visit('/')
 
@@ -286,8 +286,8 @@ module Capybara::Poltergeist
         it 'changes image dimensions' do
           @session.visit('/poltergeist/zoom_test')
 
-          black_pixels_count = ->(file) {
-            File.read(file).to_s[/{.*}/m][1...-1].split(/\W/).map{|n| n.hex.to_s(2).count('1')}.reduce(:+)
+          black_pixels_count = lambda { |file|
+            File.read(file).to_s[/{.*}/m][1...-1].split(/\W/).map { |n| n.hex.to_s(2).count('1') }.reduce(:+)
           }
           @driver.save_screenshot(file)
           before = black_pixels_count[file]
@@ -296,7 +296,7 @@ module Capybara::Poltergeist
           @driver.save_screenshot(file)
           after = black_pixels_count[file]
 
-          expect(after.to_f/before.to_f).to eq(zoom_factor**2)
+          expect(after.to_f / before.to_f).to eq(zoom_factor**2)
         end
       end
 
@@ -408,8 +408,8 @@ module Capybara::Poltergeist
       it 'sets headers on the initial request' do
         @driver.headers = { 'PermanentA' => 'a' }
         @driver.add_headers('PermanentB' => 'b')
-        @driver.add_header('Referer', 'http://google.com', :permanent => false)
-        @driver.add_header('TempA', 'a', :permanent => false)
+        @driver.add_header('Referer', 'http://google.com', permanent: false)
+        @driver.add_header('TempA', 'a', permanent: false)
 
         @session.visit('/poltergeist/headers_with_ajax')
         initial_request = @session.find(:css, '#initial_request').text
@@ -427,14 +427,14 @@ module Capybara::Poltergeist
       end
 
       it 'keeps added headers on redirects by default' do
-        @driver.add_header('X-Custom-Header', '1', :permanent => false)
+        @driver.add_header('X-Custom-Header', '1', permanent: false)
         @session.visit('/poltergeist/redirect_to_headers')
         expect(@driver.body).to include('X_CUSTOM_HEADER: 1')
       end
 
       it 'does not keep added headers on redirect when ' \
          'permanent is no_redirect' do
-        @driver.add_header('X-Custom-Header', '1', :permanent => :no_redirect)
+        @driver.add_header('X-Custom-Header', '1', permanent: :no_redirect)
 
         @session.visit('/poltergeist/redirect_to_headers')
         expect(@driver.body).not_to include('X_CUSTOM_HEADER: 1')
@@ -476,7 +476,7 @@ module Capybara::Poltergeist
 
         it 'keeps temporary headers local to the current window' do
           @session.open_new_window
-          @driver.add_header('X-Custom-Header', '1', :permanent => false)
+          @driver.add_header('X-Custom-Header', '1', permanent: false)
 
           @session.switch_to_window @session.windows.last
           @session.visit('/poltergeist/headers')
@@ -489,7 +489,7 @@ module Capybara::Poltergeist
 
         it 'does not mix temporary headers with permanent ones when propagating to other windows' do
           @session.open_new_window
-          @driver.add_header('X-Custom-Header', '1', :permanent => false)
+          @driver.add_header('X-Custom-Header', '1', permanent: false)
           @driver.add_header('Host', 'foo.com')
 
           @session.switch_to_window @session.windows.last
@@ -505,7 +505,7 @@ module Capybara::Poltergeist
 
         it 'does not propagate temporary headers to new windows' do
           @session.visit '/'
-          @driver.add_header('X-Custom-Header', '1', :permanent => false)
+          @driver.add_header('X-Custom-Header', '1', permanent: false)
           @session.open_new_window
 
           @session.switch_to_window @session.windows.last
@@ -562,8 +562,8 @@ module Capybara::Poltergeist
         @extended_driver = Capybara::Poltergeist::Driver.new(
           @session.app,
           logger: TestSessions.logger,
-          inspector: ENV['DEBUG'] != nil,
-          extensions: %W% #{File.expand_path '../../support/geolocation.js', __FILE__ } %
+          inspector: !ENV['DEBUG'].nil?,
+          extensions: %W[#{File.expand_path '../support/geolocation.js', __dir__}]
         )
       end
 
@@ -573,8 +573,9 @@ module Capybara::Poltergeist
 
       it 'supports extending the phantomjs world' do
         @extended_driver.visit session_url('/poltergeist/requiring_custom_extension')
-        expect(@extended_driver.body).
-          to include(%Q%Location: <span id="location">1,-1</span>%)
+        expect(
+          @extended_driver.body
+        ).to include(%(Location: <span id="location">1,-1</span>))
         expect(
           @extended_driver.evaluate_script("document.getElementById('location').innerHTML")
         ).to eq('1,-1')
@@ -588,8 +589,8 @@ module Capybara::Poltergeist
           @failing_driver = Capybara::Poltergeist::Driver.new(
             @session.app,
             logger: TestSessions.logger,
-            inspector: ENV['DEBUG'] != nil,
-            extensions: %W% #{File.expand_path '../../support/non_existent.js', __FILE__} %
+            inspector: !ENV['DEBUG'].nil?,
+            extensions: %W[#{File.expand_path '../support/non_existent.js', __dir__}]
           )
           expect { @failing_driver.visit '/' }.to raise_error(Capybara::Poltergeist::BrowserError, /Unable to load extension: .*non_existent\.js/)
         ensure
@@ -600,9 +601,9 @@ module Capybara::Poltergeist
 
     context 'javascript errors' do
       it 'propagates a Javascript error inside Poltergeist to a ruby exception' do
-        expect {
+        expect do
           @driver.browser.command 'browser_error'
-        }.to raise_error(BrowserError) { |e|
+        end.to raise_error(BrowserError) { |e|
           expect(e.message).to include('Error: zomg')
           # PhantomJS 2.1 refers to files as being in code subdirectory
           expect(e.message).to include('compiled/browser.js').or include('code/browser.js')
@@ -610,25 +611,25 @@ module Capybara::Poltergeist
       end
 
       it 'propagates an asynchronous Javascript error on the page to a ruby exception' do
-        expect {
+        expect do
           @driver.execute_script 'setTimeout(function() { omg }, 0)'
           sleep 0.01
           @driver.execute_script ''
-        }.to raise_error(JavascriptError, /ReferenceError.*omg/)
+        end.to raise_error(JavascriptError, /ReferenceError.*omg/)
       end
 
       it 'propagates a synchronous Javascript error on the page to a ruby exception' do
-        expect {
+        expect do
           @driver.execute_script 'omg'
-        }.to raise_error(JavascriptError, /ReferenceError.*omg/)
+        end.to raise_error(JavascriptError, /ReferenceError.*omg/)
       end
 
       it 'does not re-raise a Javascript error if it is rescued' do
-        expect {
+        expect do
           @driver.execute_script 'setTimeout(function() { omg }, 0)'
           sleep 0.01
           @driver.execute_script ''
-        }.to raise_error(JavascriptError)
+        end.to raise_error(JavascriptError)
 
         # should not raise again
         expect(@driver.evaluate_script('1+1')).to eq(2)
@@ -646,7 +647,7 @@ module Capybara::Poltergeist
           sleep 0.1
           expect(driver.body).to include('hello')
         ensure
-          driver.quit if driver
+          driver&.quit
         end
       end
 
@@ -659,7 +660,7 @@ module Capybara::Poltergeist
           sleep 0.1
           expect(driver.body).to include('hello')
         ensure
-          driver.quit if driver
+          driver&.quit
         end
       end
 
@@ -670,7 +671,7 @@ module Capybara::Poltergeist
             driver.visit session_url('/poltergeist/headers')
             expect(driver.body).to include('USER_AGENT: PageSettingsOverride')
           ensure
-            driver.quit if driver
+            driver&.quit
           end
         end
 
@@ -679,12 +680,11 @@ module Capybara::Poltergeist
             # If PJS resource timeout is less than drivers timeout it should ignore resources not loading in time
             driver = Capybara::Poltergeist::Driver.new(@session.app, page_settings: { resourceTimeout: 1000 }, logger: TestSessions.logger)
             driver.timeout = 3
-            start = Time.now
-            expect{
+            expect do
               driver.visit session_url('/poltergeist/visit_timeout')
-            }.not_to raise_error
+            end.not_to raise_error
           ensure
-            driver.quit if driver
+            driver&.quit
           end
         end
       end
@@ -703,18 +703,18 @@ module Capybara::Poltergeist
 
       it 'has a descriptive message when DNS incorrect' do
         url = "http://nope:#{@port}/"
-        expect {
+        expect do
           @session.visit(url)
-        }.to raise_error(StatusFailError, "Request to '#{url}' failed to reach server, check DNS and/or server status")
+        end.to raise_error(StatusFailError, "Request to '#{url}' failed to reach server, check DNS and/or server status")
       end
 
       it 'reports open resource requests' do
         old_timeout = @session.driver.timeout
         begin
           @session.driver.timeout = 2
-          expect{
+          expect do
             @session.visit('/poltergeist/visit_timeout')
-          }.to raise_error(StatusFailError, /resources still waiting http:\/\/.*\/poltergeist\/really_slow/)
+          end.to raise_error(StatusFailError, %r{resources still waiting http://.*/poltergeist/really_slow})
         ensure
           @session.driver.timeout = old_timeout
         end
@@ -724,9 +724,9 @@ module Capybara::Poltergeist
         old_timeout = @session.driver.timeout
         begin
           @session.driver.timeout = 2
-          expect{
+          expect do
             @session.visit('/poltergeist/really_slow')
-          }.to raise_error(StatusFailError) {|error|
+          end.to raise_error(StatusFailError) { |error|
             expect(error.message).not_to include('resources still waiting')
           }
         ensure
@@ -814,14 +814,13 @@ module Capybara::Poltergeist
       end
     end
 
-    context "memory cache clearing" do
-
+    context 'memory cache clearing' do
       before do
         @driver.restart
       end
 
-      it "can clear memory cache when supported (phantomjs >=2.0.0)" do
-        skip "clear_memory_cache is not supported by tested PhantomJS" unless phantom_version_is? ">= 2.0.0", @driver
+      it 'can clear memory cache when supported (phantomjs >=2.0.0)' do
+        skip 'clear_memory_cache is not supported by tested PhantomJS' unless phantom_version_is? '>= 2.0.0', @driver
 
         @driver.clear_memory_cache
 
@@ -841,15 +840,15 @@ module Capybara::Poltergeist
         expect(another_request.response_parts.last.status).to eq(200)
       end
 
-      it "raises error when it is unsupported (phantomjs <2.0.0)" do
-        skip "clear_memory_cache is supported by tested PhantomJS" if phantom_version_is? ">= 2.0.0", @driver
+      it 'raises error when it is unsupported (phantomjs <2.0.0)' do
+        skip 'clear_memory_cache is supported by tested PhantomJS' if phantom_version_is? '>= 2.0.0', @driver
 
         @session.visit('/poltergeist/cacheable')
         first_request = @driver.network_traffic.last
         expect(@driver.network_traffic.length).to eq(1)
         expect(first_request.response_parts.last.status).to eq(200)
 
-        expect{@driver.clear_memory_cache}.to raise_error(Capybara::Poltergeist::UnsupportedFeature)
+        expect { @driver.clear_memory_cache }.to raise_error(Capybara::Poltergeist::UnsupportedFeature)
 
         @session.visit('/poltergeist/cacheable')
         expect(@driver.network_traffic.length).to eq(2)
@@ -996,14 +995,14 @@ module Capybara::Poltergeist
         # If var is unspecified, skip test
         host = ENV['POLTERGEIST_TEST_HOST']
 
-        skip "POLTERGEIST_TEST_HOST not set" if host.nil?
+        skip 'POLTERGEIST_TEST_HOST not set' if host.nil?
 
         driver = Capybara::Poltergeist::Driver.new(@driver.app, host: host, port: 12345)
         driver.visit session_url('/')
 
         expect { TCPServer.new(host, 12345) }.to raise_error(Errno::EADDRINUSE)
       ensure
-        driver.quit if driver
+        driver&.quit
       end
     end
 
@@ -1014,7 +1013,7 @@ module Capybara::Poltergeist
         window.open('/poltergeist/simple', 'popup')
       JS
 
-      expect(@driver.window_handles).to eq(['0', '1'])
+      expect(@driver.window_handles).to eq(%w[0 1])
 
       popup2 = @session.window_opened_by do
         @session.execute_script <<-JS
@@ -1022,24 +1021,24 @@ module Capybara::Poltergeist
         JS
       end
 
-      expect(@driver.window_handles).to eq(['0', '1', '2'])
+      expect(@driver.window_handles).to eq(%w[0 1 2])
 
       @session.within_window(popup2) do
         expect(@session.html).to include('Test')
         @session.execute_script('window.close()')
       end
 
-      sleep 0.1;
+      sleep 0.1
 
-      expect(@driver.window_handles).to eq(['0', '1'])
+      expect(@driver.window_handles).to eq(%w[0 1])
     end
 
     context 'a new window inherits settings' do
       it 'inherits size' do
         @session.visit '/'
-        @session.current_window.resize_to(1200,800)
+        @session.current_window.resize_to(1200, 800)
         new_tab = @session.open_new_window
-        expect(new_tab.size).to eq [1200,800]
+        expect(new_tab.size).to eq [1200, 800]
       end
 
       it 'inherits url_blacklist' do
@@ -1067,14 +1066,13 @@ module Capybara::Poltergeist
             expect(@session).to have_content('We should see this.')
           end
           @session.within_frame 'unwantedframe' do
-            #make sure non whitelisted urls are blocked
+            # make sure non whitelisted urls are blocked
             expect(@session).not_to have_content("We shouldn't see this.")
           end
         end
       end
     end
 
-
     it 'resizes windows' do
       @session.visit '/'
 
@@ -1090,11 +1088,11 @@ module Capybara::Poltergeist
         JS
       end
 
-      popup1.resize_to(100,200)
-      popup2.resize_to(200,100)
+      popup1.resize_to(100, 200)
+      popup2.resize_to(200, 100)
 
-      expect(popup1.size).to eq([100,200])
-      expect(popup2.size).to eq([200,100])
+      expect(popup1.size).to eq([100, 200])
+      expect(popup2.size).to eq([200, 100])
     end
 
     it 'clears local storage between tests' do
@@ -1282,7 +1280,7 @@ module Capybara::Poltergeist
         end
 
         session.within_frame 'unwantedframe' do
-          #make sure non whitelisted urls are blocked
+          # make sure non whitelisted urls are blocked
           expect(session).not_to have_content("We shouldn't see this.")
         end
 
@@ -1294,13 +1292,12 @@ module Capybara::Poltergeist
           expect(session).to have_content('We should see this.')
         end
         session.within_frame 'unwantedframe' do
-          #make sure non whitelisted urls are blocked
+          # make sure non whitelisted urls are blocked
           expect(session).not_to have_content("We shouldn't see this.")
         end
       end
     end
 
-
     context 'has ability to send keys' do
       before { @session.visit('/poltergeist/send_keys') }
 
@@ -1389,7 +1386,7 @@ module Capybara::Poltergeist
       it 'sends sequences with modifiers and symbols' do
         input = @session.find(:css, '#empty_input')
 
-        input.native.send_keys('t', 'r', 'i', 'n', 'g', [:Ctrl, :Left], 's')
+        input.native.send_keys('t', 'r', 'i', 'n', 'g', %i[Ctrl Left], 's')
 
         expect(input.value).to eq('string')
       end
@@ -1397,7 +1394,7 @@ module Capybara::Poltergeist
       it 'sends sequences with multiple modifiers and symbols' do
         input = @session.find(:css, '#empty_input')
 
-        input.native.send_keys('t', 'r', 'i', 'n', 'g', [:Ctrl, :Shift, :Left], 's')
+        input.native.send_keys('t', 'r', 'i', 'n', 'g', %i[Ctrl Shift Left], 's')
 
         expect(input.value).to eq('s')
       end
@@ -1413,7 +1410,7 @@ module Capybara::Poltergeist
       it 'sends modifiers with multiple keys' do
         input = @session.find(:css, '#empty_input')
 
-        input.native.send_keys('poltre', [:Shift, :Left, :Left], 'ergeist')
+        input.native.send_keys('poltre', %i[Shift Left Left], 'ergeist')
 
         expect(input.value).to eq('poltergeist')
       end
@@ -1431,38 +1428,38 @@ module Capybara::Poltergeist
 
         input.send_keys([:shift, '.'], [:shift, 't'])
 
-        expect(@session.find(:css, '#key-events-output')).to have_text("keydown:16 keydown:190 keydown:16 keydown:84")
+        expect(@session.find(:css, '#key-events-output')).to have_text('keydown:16 keydown:190 keydown:16 keydown:84')
       end
 
       it 'suuports snake_case sepcified keys (Capybara standard)' do
         input = @session.find(:css, '#empty_input')
         input.send_keys(:PageUp, :page_up)
-        expect(@session.find(:css, '#key-events-output')).to have_text("keydown:33", count: 2)
+        expect(@session.find(:css, '#key-events-output')).to have_text('keydown:33', count: 2)
       end
 
       it 'supports :control alias for :Ctrl' do
         input = @session.find(:css, '#empty_input')
         input.send_keys([:Ctrl, 'a'], [:control, 'a'])
-        expect(@session.find(:css, '#key-events-output')).to have_text("keydown:17 keydown:65", count: 2)
+        expect(@session.find(:css, '#key-events-output')).to have_text('keydown:17 keydown:65', count: 2)
       end
 
       it 'supports :command alias for :Meta' do
         input = @session.find(:css, '#empty_input')
         input.send_keys([:Meta, 'z'], [:command, 'z'])
-        expect(@session.find(:css, '#key-events-output')).to have_text("keydown:91 keydown:90", count: 2)
+        expect(@session.find(:css, '#key-events-output')).to have_text('keydown:91 keydown:90', count: 2)
       end
 
       it 'supports Capybara specified numpad keys' do
         input = @session.find(:css, '#empty_input')
         input.send_keys(:numpad2, :numpad8, :divide, :decimal)
-        expect(@session.find(:css, '#key-events-output')).to have_text("keydown:98 keydown:104 keydown:111 keydown:110")
+        expect(@session.find(:css, '#key-events-output')).to have_text('keydown:98 keydown:104 keydown:111 keydown:110')
       end
 
       it 'raises error for unknown keys' do
         input = @session.find(:css, '#empty_input')
-        expect {
+        expect do
           input.send_keys('abc', :blah)
-        }.to raise_error Capybara::Poltergeist::KeyError, 'Unknown key: Blah'
+        end.to raise_error Capybara::Poltergeist::KeyError, 'Unknown key: Blah'
       end
     end
 
@@ -1487,10 +1484,10 @@ module Capybara::Poltergeist
         expect(input.text).to eq('replacement text')
       end
 
-      it "sets a content editable childs content" do
+      it 'sets a content editable childs content' do
         @session.visit('/with_js')
-        @session.find(:css,'#existing_content_editable_child').set('WYSIWYG')
-        expect(@session.find(:css,'#existing_content_editable_child').text).to eq('WYSIWYG')
+        @session.find(:css, '#existing_content_editable_child').set('WYSIWYG')
+        expect(@session.find(:css, '#existing_content_editable_child').text).to eq('WYSIWYG')
       end
     end
 
@@ -1512,22 +1509,22 @@ module Capybara::Poltergeist
       end
     end
 
-    context 'evaluate_script'do
+    context 'evaluate_script' do
       it 'can return an element' do
         @session.visit('/poltergeist/send_keys')
         element = @session.driver.evaluate_script('document.getElementById("empty_input")')
         expect(element).to eq(@session.find(:id, 'empty_input').native)
       end
 
-      it 'can return structures with elements'  do
+      it 'can return structures with elements' do
         @session.visit('/poltergeist/send_keys')
         result = @session.driver.evaluate_script('{ a: document.getElementById("empty_input"), b: { c: document.querySelectorAll("#empty_textarea, #filled_textarea") } }')
-        expect(result).to eq({
+        expect(result).to eq(
           'a' => @session.driver.find_css('#empty_input').first,
           'b' => {
             'c' => @session.driver.find_css('#empty_textarea, #filled_textarea')
           }
-        })
+        )
       end
     end
 
@@ -1537,15 +1534,15 @@ module Capybara::Poltergeist
           expect(@session.driver.evaluate_async_script('arguments[0](null)')).to be_nil
           expect(@session.driver.evaluate_async_script('arguments[0](false)')).to be false
           expect(@session.driver.evaluate_async_script('arguments[0](true)')).to be true
-          expect(@session.driver.evaluate_async_script("arguments[0]({foo: 'bar'})")).to eq({'foo' => 'bar'})
+          expect(@session.driver.evaluate_async_script("arguments[0]({foo: 'bar'})")).to eq('foo' => 'bar')
         end
       end
 
       it 'will timeout' do
         @session.using_wait_time(1) do
-          expect {
+          expect do
             @session.driver.evaluate_async_script('var callback=arguments[0]; setTimeout(function(){callback(true)}, 4000)')
-          }.to raise_error Capybara::Poltergeist::ScriptTimeoutError
+          end.to raise_error Capybara::Poltergeist::ScriptTimeoutError
         end
       end
     end
diff --git a/spec/integration/session_spec.rb b/spec/integration/session_spec.rb
index fde19d4..13511dc 100644
--- a/spec/integration/session_spec.rb
+++ b/spec/integration/session_spec.rb
@@ -1,4 +1,3 @@
-# coding: utf-8
 # frozen_string_literal: true
 
 require 'spec_helper'
@@ -57,11 +56,11 @@ describe Capybara::Session do
       context 'when someone (*cough* prototype *cough*) messes with Array#toJSON' do
         before do
           @session.visit('/poltergeist/index')
-          array_munge = <<-EOS
+          array_munge = <<-JS
           Array.prototype.toJSON = function() {
             return "ohai";
           }
-          EOS
+          JS
           @session.execute_script array_munge
         end
 
@@ -193,7 +192,7 @@ describe Capybara::Session do
 
       it 'accepts negatives in a number field' do
         element = @session.find(:css, '#change_me_number')
-        element.set -100
+        element.set(-100)
         expect(element.value).to eq('-100')
       end
 
@@ -290,13 +289,13 @@ describe Capybara::Session do
       end
 
       it 'gets innerHTML' do
-        expect(@session.find(:css,'.some_other_class')['innerHTML']).to eq '<p>foobar</p>'
+        expect(@session.find(:css, '.some_other_class')['innerHTML']).to eq '<p>foobar</p>'
       end
 
       it 'gets attribute' do
         link = @session.find(:link, 'Loop')
         expect(link['data-random']).to eq '42'
-        expect(link['onclick']).to eq "return false;"
+        expect(link['onclick']).to eq 'return false;'
       end
 
       it 'gets boolean attributes as booleans' do
@@ -355,7 +354,7 @@ describe Capybara::Session do
       expect(@session.evaluate_script('null')).to be_nil
       expect(@session.evaluate_script('false')).to be false
       expect(@session.evaluate_script('true')).to be true
-      expect(@session.evaluate_script("{foo: 'bar'}")).to eq({'foo' => 'bar'})
+      expect(@session.evaluate_script("{foo: 'bar'}")).to eq('foo' => 'bar')
     end
 
     it 'can evaluate a statement ending with a semicolon' do
@@ -382,8 +381,8 @@ describe Capybara::Session do
         @session.driver.resize(200, 200)
         log = @session.find(:css, '#log')
 
-        instructions = %w(one four one two three)
-        instructions.each do |instruction, i|
+        instructions = %w[one four one two three]
+        instructions.each do |instruction|
           @session.find(:css, "##{instruction}").click
           expect(log.text).to eq(instruction)
         end
@@ -411,18 +410,18 @@ describe Capybara::Session do
         end
 
         it 'detects if an element is obscured when clicking' do
-          expect {
+          expect do
             @session.find(:css, '#one').click
-          }.to raise_error(Capybara::Poltergeist::MouseEventFailed) { |error|
+          end.to raise_error(Capybara::Poltergeist::MouseEventFailed) { |error|
             expect(error.selector).to eq('html body div#two.box')
             expect(error.message).to include('[200, 200]')
           }
         end
 
         it 'clicks in the centre of an element' do
-          expect {
+          expect do
             @session.find(:css, '#one').click
-          }.to raise_error(Capybara::Poltergeist::MouseEventFailed) { |error|
+          end.to raise_error(Capybara::Poltergeist::MouseEventFailed) { |error|
             expect(error.position).to eq([200, 200])
           }
         end
@@ -430,9 +429,9 @@ describe Capybara::Session do
         it 'clicks in the centre of an element within the viewport, if part is outside the viewport' do
           @session.driver.resize(200, 200)
 
-          expect {
+          expect do
             @session.find(:css, '#one').click
-          }.to raise_error(Capybara::Poltergeist::MouseEventFailed) { |error|
+          end.to raise_error(Capybara::Poltergeist::MouseEventFailed) { |error|
             expect(error.position.first).to eq(150)
           }
         end
@@ -449,16 +448,16 @@ describe Capybara::Session do
         end
 
         it 'detects if an element is obscured when clicking' do
-          expect {
+          expect do
             @session.find(:css, '#one').click
-          }.to raise_error(Capybara::Poltergeist::MouseEventFailed) { |error|
+          end.to raise_error(Capybara::Poltergeist::MouseEventFailed) { |error|
             expect(error.selector).to eq('html body svg#svg.box')
             expect(error.message).to include('[200, 200]')
           }
         end
       end
 
-      context "with image maps" do
+      context 'with image maps' do
         before do
           @session.visit('/poltergeist/image_map')
         end
@@ -471,12 +470,12 @@ describe Capybara::Session do
         end
 
         it "doesn't click if the associated img is hidden" do
-          expect {
+          expect do
             @session.find(:css, 'map[name=testmap2] area[shape=circle]').click
-          }.to raise_error(Capybara::ElementNotFound)
-          expect {
+          end.to raise_error(Capybara::ElementNotFound)
+          expect do
             @session.find(:css, 'map[name=testmap2] area[shape=circle]', visible: false).click
-          }.to raise_error(Capybara::Poltergeist::MouseEventFailed)
+          end.to raise_error(Capybara::Poltergeist::MouseEventFailed)
         end
       end
     end
@@ -490,8 +489,8 @@ describe Capybara::Session do
         @session.driver.resize(200, 200)
         log = @session.find(:css, '#log')
 
-        instructions = %w(one four one two three)
-        instructions.each do |instruction, i|
+        instructions = %w[one four one two three]
+        instructions.each do |instruction|
           @session.find(:css, "##{instruction}").base.double_click
           expect(log.text).to eq(instruction)
         end
@@ -531,7 +530,7 @@ describe Capybara::Session do
           return a;
         })()
       JS
-      expect(@session.evaluate_script(code)).to eq({"a"=>"(cyclic structure)", "b"=>{}, "c"=>{"a"=>"(cyclic structure)"}})
+      expect(@session.evaluate_script(code)).to eq('a' => '(cyclic structure)', 'b' => {}, 'c' => { 'a' => '(cyclic structure)' })
     end
 
     if Capybara::VERSION.to_f < 3.0
@@ -548,12 +547,12 @@ describe Capybara::Session do
 
     it 'handles hash changes' do
       @session.visit '/#omg'
-      expect(@session.current_url).to match(/\/#omg$/)
+      expect(@session.current_url).to match(%r{/#omg$})
       @session.execute_script <<-JS
         window.onhashchange = function() { window.last_hashchange = window.location.hash }
       JS
       @session.visit '/#foo'
-      expect(@session.current_url).to match(/\/#foo$/)
+      expect(@session.current_url).to match(%r{/#foo$})
       expect(@session.evaluate_script('window.last_hashchange')).to eq('#foo')
     end
 
@@ -571,12 +570,12 @@ describe Capybara::Session do
       end
 
       it 'supports url in parameter' do
-        @session.visit "/poltergeist/arbitrary_path/200/foo%20asd?a=http://example.com/asd%20asd"
+        @session.visit '/poltergeist/arbitrary_path/200/foo%20asd?a=http://example.com/asd%20asd'
         expect(request_uri).to eq('/poltergeist/arbitrary_path/200/foo%20asd?a=http://example.com/asd%20asd')
       end
 
       it 'supports restricted characters " []:/+&="' do
-        @session.visit "/poltergeist/arbitrary_path/200/foo?a=%20%5B%5D%3A%2F%2B%26%3D"
+        @session.visit '/poltergeist/arbitrary_path/200/foo?a=%20%5B%5D%3A%2F%2B%26%3D'
         expect(request_uri).to eq('/poltergeist/arbitrary_path/200/foo?a=%20%5B%5D%3A%2F%2B%26%3D')
       end
 
@@ -596,7 +595,7 @@ describe Capybara::Session do
         droppable = @session.find(:css, '#drag_to #droppable')
 
         draggable.drag_to(droppable)
-        expect( droppable ).to have_content( "Dropped" )
+        expect(droppable).to have_content('Dropped')
       end
 
       it 'supports drag_by on native element' do
@@ -610,10 +609,9 @@ describe Capybara::Session do
         top_after = @session.evaluate_script('$("#drag_by .draggable").position().top')
         left_after = @session.evaluate_script('$("#drag_by .draggable").position().left')
 
-        expect( top_after ).to eq( top_before + 15 )
-        expect( left_after ).to eq( left_before + 15 )
+        expect(top_after).to eq(top_before + 15)
+        expect(left_after).to eq(left_before + 15)
       end
-
     end
 
     context 'window switching support' do
@@ -721,7 +719,7 @@ describe Capybara::Session do
         expect(@session.driver.frame_url).to end_with('/poltergeist/frames')
       end
 
-      context "with src == about:blank" do
+      context 'with src == about:blank' do
         it "doesn't hang if no document created" do
           @session.visit '/'
           @session.execute_script <<-JS
@@ -749,9 +747,9 @@ describe Capybara::Session do
         end
       end
 
-      context "with no src attribute" do
+      context 'with no src attribute' do
         it "doesn't hang if the srcdoc attribute is used" do
-          skip "srcdoc attribute not supported by tested PhantomJS version" unless phantom_version_is? ">= 2.0.0", @session.driver
+          skip 'srcdoc attribute not supported by tested PhantomJS version' unless phantom_version_is? '>= 2.0.0', @session.driver
           @session.visit '/'
           @session.execute_script <<-JS
             document.body.innerHTML += '<iframe srcdoc="<p>Hello Frame</p>" name="frame">'
@@ -833,11 +831,11 @@ describe Capybara::Session do
       it 'does not wait forever for the frame to load' do
         @session.visit '/'
 
-        expect {
-          @session.within_frame('omg') { }
-        }.to raise_error { |e|
+        expect do
+          @session.within_frame('omg') {}
+        end.to(raise_error do |e|
           expect(e).to be_a(Capybara::Poltergeist::FrameNotFound).or be_a(Capybara::ElementNotFound)
-        }
+        end)
       end
     end
 
@@ -851,7 +849,7 @@ describe Capybara::Session do
       @session.visit('/')
       @session.find(:css, 'a').click
 
-      position = JSON.load(TestSessions.logger.messages.last)['response']['position']
+      position = JSON.parse(TestSessions.logger.messages.last)['response']['position']
       expect(position['x']).to_not be_nil
       expect(position['y']).to_not be_nil
     end
@@ -910,21 +908,21 @@ describe Capybara::Session do
       end
 
       it 'gets property innerHTML' do
-        expect(@session.find(:css,'.some_other_class').native.property('innerHTML')).to eq '<p>foobar</p>'
+        expect(@session.find(:css, '.some_other_class').native.property('innerHTML')).to eq '<p>foobar</p>'
       end
 
       it 'gets property outerHTML' do
-        expect(@session.find(:css,'.some_other_class').native.property('outerHTML')).to eq '<div class="some_other_class"><p>foobar</p></div>'
+        expect(@session.find(:css, '.some_other_class').native.property('outerHTML')).to eq '<div class="some_other_class"><p>foobar</p></div>'
       end
 
       it 'gets non existent property' do
-        expect(@session.find(:css,'.some_other_class').native.property('does_not_exist')).to eq nil
+        expect(@session.find(:css, '.some_other_class').native.property('does_not_exist')).to eq nil
       end
     end
 
     it 'allows access to element attributes' do
       @session.visit '/poltergeist/attributes_properties'
-      expect(@session.find(:css,'#my_link').native.attributes).to eq(
+      expect(@session.find(:css, '#my_link').native.attributes).to eq(
         'href' => '#', 'id' => 'my_link', 'class' => 'some_class', 'data' => 'rah!'
       )
     end
@@ -932,7 +930,7 @@ describe Capybara::Session do
     it 'knows about its parents' do
       @session.visit '/poltergeist/simple'
       parents = @session.find(:css, '#nav').native.parents
-      expect(parents.map(&:tag_name)).to eq ['li','ul','body','html']
+      expect(parents.map(&:tag_name)).to eq %w[li ul body html]
     end
 
     context 'SVG tests' do
@@ -948,33 +946,33 @@ describe Capybara::Session do
     context 'modals' do
       it 'matches on partial strings' do
         @session.visit '/poltergeist/with_js'
-        expect {
+        expect do
           @session.accept_confirm '[reg.exp] (chara©+er$)' do
             @session.click_link('Open for match')
           end
-        }.not_to raise_error
+        end.not_to raise_error
         expect(@session).to have_xpath("//a[@id='open-match' and @confirmed='true']")
       end
 
       it 'matches on regular expressions' do
         @session.visit '/poltergeist/with_js'
-        expect {
+        expect do
           @session.accept_confirm(/^.t.ext.*\[\w{3}\.\w{3}\]/i) do
             @session.click_link('Open for match')
           end
-        }.not_to raise_error
+        end.not_to raise_error
         expect(@session).to have_xpath("//a[@id='open-match' and @confirmed='true']")
       end
 
       it 'works with nested modals' do
         @session.visit '/poltergeist/with_js'
-        expect {
+        expect do
           @session.dismiss_confirm 'Are you really sure?' do
             @session.accept_confirm 'Are you sure?' do
               @session.click_link('Open check twice')
             end
           end
-        }.not_to raise_error
+        end.not_to raise_error
         expect(@session).to have_xpath("//a[@id='open-twice' and @confirmed='false']")
       end
 
@@ -988,39 +986,39 @@ describe Capybara::Session do
         end
 
         @session.within_window(popup) do
-          expect {
+          expect do
             @session.accept_confirm do
               @session.click_link('Open for match')
             end
             expect(@session).to have_xpath("//a[@id='open-match' and @confirmed='true']")
-          }.not_to raise_error
+          end.not_to raise_error
         end
         popup.close
       end
     end
 
-    it "can go back when history state has been pushed" do
+    it 'can go back when history state has been pushed' do
       @session.visit('/')
       @session.execute_script('window.history.pushState({foo: "bar"}, "title", "bar2.html");')
       expect(@session).to have_current_path('/bar2.html')
-      expect{@session.go_back}.not_to raise_error
+      expect { @session.go_back }.not_to raise_error
       expect(@session).to have_current_path('/')
     end
 
-    it "can go forward when history state is used" do
+    it 'can go forward when history state is used' do
       @session.visit('/')
       @session.execute_script('window.history.pushState({foo: "bar"}, "title", "bar2.html");')
       expect(@session).to have_current_path('/bar2.html')
-      #don't use #go_back here to isolate the test
+      # don't use #go_back here to isolate the test
       @session.execute_script('window.history.go(-1);')
       expect(@session).to have_current_path('/')
-      expect{@session.go_forward}.not_to raise_error
+      expect { @session.go_forward }.not_to raise_error
       expect(@session).to have_current_path('/bar2.html')
     end
 
-    context "in threadsafe mode" do
+    context 'in threadsafe mode' do
       before do
-        skip "No threadsafe mode in this version" unless Capybara.respond_to?(:threadsafe)
+        skip 'No threadsafe mode in this version' unless Capybara.respond_to?(:threadsafe)
         Capybara::SpecHelper.reset_threadsafe(true, @session) if Capybara.respond_to?(:threadsafe)
       end
 
@@ -1028,7 +1026,7 @@ describe Capybara::Session do
         Capybara::SpecHelper.reset_threadsafe(false, @session) if Capybara.respond_to?(:threadsafe)
       end
 
-      it "uses per session wait setting" do
+      it 'uses per session wait setting' do
         Capybara.default_max_wait_time = 1
         @session.config.default_max_wait_time = 2
         expect(@session.driver.send(:session_wait_time)).to eq 2
@@ -1041,7 +1039,7 @@ describe Capybara::Session do
 
       context 'with pty' do
         before do
-          Tempfile.open(%w(test rb)) do |file|
+          Tempfile.open(%w[test rb]) do |file|
             file.print(script)
             file.flush
 
@@ -1049,14 +1047,14 @@ describe Capybara::Session do
               PTY.spawn("bundle exec ruby #{file.path}") do |read, write, pid|
                 sleep 0.1 until read.readline.chomp == 'Please type enter'
                 write.puts
-                sleep 0.1 until status = PTY.check(pid)
+                sleep 0.1 until (status = PTY.check(pid))
                 @status = status
               end
             end
           end
         end
 
-        let(:script) {
+        let(:script) do
           <<-RUBY
             require 'capybara/poltergeist'
 
@@ -1068,7 +1066,7 @@ describe Capybara::Session do
             sleep 1
             browser.current_url
           RUBY
-        }
+        end
 
         it do
           expect(@status).to be_success
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index a2f4cdc..0e56646 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-POLTERGEIST_ROOT = File.expand_path('../..', __FILE__)
+POLTERGEIST_ROOT = File.expand_path('..', __dir__)
 $:.unshift(POLTERGEIST_ROOT + '/lib')
 
 require 'bundler/setup'
@@ -40,7 +40,7 @@ module Poltergeist
     class << self
       def set_capybara_wait_time(t)
         Capybara.default_max_wait_time = t
-      rescue
+      rescue StandardError
         Capybara.default_wait_time = t
       end
     end
@@ -64,7 +64,7 @@ RSpec.configure do |config|
 
   Capybara::SpecHelper.configure(config)
 
-  config.filter_run_excluding :full_description => lambda { |description, metadata|
+  config.filter_run_excluding full_description: lambda { |description, _metadata|
     [
       # test is marked pending in Capybara but Poltergeist passes - disable here - have our own test in driver spec
       /Capybara::Session Poltergeist node #set should allow me to change the contents of a contenteditable elements child/,
@@ -77,8 +77,8 @@ RSpec.configure do |config|
     Poltergeist::SpecHelper.set_capybara_wait_time(0)
   end
 
-  [:js, :modals, :windows].each do |cond|
-    config.before(:each, :requires => cond) do
+  %i[js modals windows].each do |cond|
+    config.before(:each, requires: cond) do
       Poltergeist::SpecHelper.set_capybara_wait_time(1)
     end
   end
@@ -87,4 +87,3 @@ end
 def phantom_version_is?(ver_spec, driver)
   Cliver.detect(driver.options[:phantomjs] || Capybara::Poltergeist::Client::PHANTOMJS_NAME, ver_spec)
 end
-
diff --git a/spec/support/test_app.rb b/spec/support/test_app.rb
index 98b0eab..9911b27 100644
--- a/spec/support/test_app.rb
+++ b/spec/support/test_app.rb
@@ -4,10 +4,10 @@ require 'capybara/spec/test_app'
 
 class TestApp
   configure do
-    set :protection, :except => :frame_options
+    set :protection, except: :frame_options
   end
-  POLTERGEIST_VIEWS  = File.dirname(__FILE__) + "/views"
-  POLTERGEIST_PUBLIC = File.dirname(__FILE__) + "/public"
+  POLTERGEIST_VIEWS  = File.dirname(__FILE__) + '/views'
+  POLTERGEIST_PUBLIC = File.dirname(__FILE__) + '/public'
 
   helpers do
     def requires_credentials(login, password)
@@ -17,8 +17,8 @@ class TestApp
     end
 
     def authorized?(login, password)
-      @auth ||=  Rack::Auth::Basic::Request.new(request.env)
-      @auth.provided? and @auth.basic? and @auth.credentials and @auth.credentials == [login, password]
+      @auth ||= Rack::Auth::Basic::Request.new(request.env)
+      @auth.provided? && @auth.basic? && @auth.credentials && (@auth.credentials == [login, password])
     end
   end
 
@@ -57,12 +57,12 @@ class TestApp
 
   get '/poltergeist/slow' do
     sleep 0.2
-    "slow page"
+    'slow page'
   end
 
   get '/poltergeist/really_slow' do
     sleep 3
-    "really slow page"
+    'really slow page'
   end
 
   get '/poltergeist/basic_auth' do
@@ -77,7 +77,7 @@ class TestApp
 
   get '/poltergeist/cacheable' do
     cache_control :public, max_age: 60
-    etag "deadbeef"
+    etag 'deadbeef'
     'Cacheable request'
   end
 
diff --git a/spec/unit/browser_spec.rb b/spec/unit/browser_spec.rb
index d95d35a..83bbfdc 100644
--- a/spec/unit/browser_spec.rb
+++ b/spec/unit/browser_spec.rb
@@ -19,7 +19,7 @@ module Capybara::Poltergeist
         subject.command('where is', 'the love?')
 
         expect(logger.string).to include('"name":"where is","args":["the love?"]')
-        expect(logger.string).to include("#{response}")
+        expect(logger.string).to include(response)
       end
     end
   end
diff --git a/spec/unit/client_spec.rb b/spec/unit/client_spec.rb
index 4ba6a18..a1e4395 100644
--- a/spec/unit/client_spec.rb
+++ b/spec/unit/client_spec.rb
@@ -4,7 +4,7 @@ require 'spec_helper'
 
 module Capybara::Poltergeist
   describe Client do
-    let(:server) { double(port: 6000, host: "127.0.0.1") }
+    let(:server) { double(port: 6000, host: '127.0.0.1') }
     let(:client_params) { {} }
     subject { Client.new(server, client_params) }
 
diff --git a/spec/unit/driver_spec.rb b/spec/unit/driver_spec.rb
index 1089c54..698b1df 100644
--- a/spec/unit/driver_spec.rb
+++ b/spec/unit/driver_spec.rb
@@ -23,22 +23,22 @@ module Capybara::Poltergeist
     end
 
     context 'with a phantomjs_options option' do
-      subject { Driver.new(nil, phantomjs_options: %w{--hello})}
+      subject { Driver.new(nil, phantomjs_options: %w[--hello]) }
 
-      it "is a combination of ssl settings and the provided options" do
-        expect(subject.phantomjs_options).to eq(%w{--hello --ignore-ssl-errors=yes --ssl-protocol=TLSv1})
+      it 'is a combination of ssl settings and the provided options' do
+        expect(subject.phantomjs_options).to eq(%w[--hello --ignore-ssl-errors=yes --ssl-protocol=TLSv1])
       end
     end
 
     context 'with phantomjs_options containing ssl-protocol settings' do
-      subject { Driver.new(nil, phantomjs_options: %w{--ssl-protocol=any --ignore-ssl-errors=no})}
+      subject { Driver.new(nil, phantomjs_options: %w[--ssl-protocol=any --ignore-ssl-errors=no]) }
 
-      it "uses the provided ssl-protocol" do
+      it 'uses the provided ssl-protocol' do
         expect(subject.phantomjs_options).to include('--ssl-protocol=any')
         expect(subject.phantomjs_options).not_to include('--ssl-protocol=TLSv1')
       end
 
-      it "uses the provided ssl-errors" do
+      it 'uses the provided ssl-errors' do
         expect(subject.phantomjs_options).to include('--ignore-ssl-errors=no')
         expect(subject.phantomjs_options).not_to include('--ignore-ssl-errors=yes')
       end
@@ -78,11 +78,11 @@ module Capybara::Poltergeist
       end
 
       it 'can pause indefinitely' do
-        expect {
-          Timeout::timeout(3) do
+        expect do
+          Timeout.timeout(3) do
             subject.pause
           end
-        }.to raise_error(Timeout::Error)
+        end.to raise_error(Timeout::Error)
       end
 
       it 'can pause and resume with keyboard input' do
@@ -91,7 +91,7 @@ module Capybara::Poltergeist
           write_io.write "\n"
 
           begin
-            Timeout::timeout(3) do
+            Timeout.timeout(3) do
               subject.pause
             end
           ensure
@@ -102,11 +102,10 @@ module Capybara::Poltergeist
 
       it 'can pause and resume with signal' do
         Thread.new { sleep(2); Process.kill('CONT', Process.pid); }
-        Timeout::timeout(4) do
+        Timeout.timeout(4) do
           subject.pause
         end
       end
-
     end
 
     context 'with a :timeout option' do