diff --git a/.gitignore b/.gitignore
index 402e6c2..83a9588 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@ pkg/*
 coverage
 tmp/
 Gemfile.lock
+.vagrant
diff --git a/.rubocop.yml b/.rubocop.yml
index 27ed16e..89c4dbc 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -4,7 +4,8 @@ AllCops:
     - 'tmp/**/*'
     - Gemfile
   DisplayCopNames: true
-  TargetRubyVersion: 2.3
+  TargetRubyVersion: 3.4
+  NewCops: enable
 
 Style/GuardClause:
   Enabled: false
@@ -13,7 +14,7 @@ Metrics/AbcSize:
   Max: 38
 
 # Configuration parameters: AllowURI.
-Metrics/LineLength:
+Layout/LineLength:
   Max: 225
 
 # Configuration parameters: CountKeywordArgs.
@@ -31,19 +32,16 @@ Metrics/ClassLength:
   Max: 174
 
 Metrics/CyclomaticComplexity:
-  Max: 7
+  Max: 9
 
 # Configuration parameters: CountComments.
 Metrics/MethodLength:
   Max: 76
 
 Metrics/PerceivedComplexity:
-  Max: 8
+  Max: 9
 
 # Configuration parameters: EnforcedStyle, SupportedStyles.
-Style/MethodName:
+Naming/MethodName:
   Exclude:
     - lib/proxy_pac_rb/environment.rb
-
-Style/GuardClause:
-  Enabled: false
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 4fe0df7..ff067b3 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,27 +1,90 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2017-06-04 19:50:00 +0000 using RuboCop version 0.49.1.
+# on 2025-02-03 22:23:49 UTC using RuboCop version 1.71.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
-# Offense count: 82
-# Cop supports --auto-correct.
+# Offense count: 6
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: Include.
+# Include: **/*.gemspec
+Gemspec/AddRuntimeDependency:
+  Exclude:
+    - 'proxy_pac_rb.gemspec'
+
+# Offense count: 1
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: Severity, Include.
+# Include: **/*.gemspec
+Gemspec/DeprecatedAttributeAssignment:
+  Exclude:
+    - 'proxy_pac_rb.gemspec'
+
+# Offense count: 3
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: TreatCommentsAsGroupSeparators, ConsiderPunctuation, Include.
+# Include: **/*.gemspec
+Gemspec/OrderedDependencies:
+  Exclude:
+    - 'proxy_pac_rb.gemspec'
+
+# Offense count: 1
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: Severity, Include.
+# Include: **/*.gemspec
+Gemspec/RequireMFA:
+  Exclude:
+    - 'proxy_pac_rb.gemspec'
+
+# Offense count: 1
+# Configuration parameters: Severity, Include.
+# Include: **/*.gemspec
+Gemspec/RequiredRubyVersion:
+  Exclude:
+    - 'proxy_pac_rb.gemspec'
+
+# Offense count: 3
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: EnforcedStyleAlignWith, Severity.
+# SupportedStylesAlignWith: start_of_line, begin
+Layout/BeginEndAlignment:
+  Exclude:
+    - 'lib/proxy_pac_rb/rspec/helpers.rb'
+    - 'lib/proxy_pac_rb/rspec/matchers/proxy.rb'
+
+# Offense count: 1
+# This cop supports safe autocorrection (--autocorrect).
+Layout/ClosingHeredocIndentation:
+  Exclude:
+    - 'proxy_pac_rb.gemspec'
+
+# Offense count: 1
+# This cop supports safe autocorrection (--autocorrect).
+Layout/EmptyLineAfterGuardClause:
+  Exclude:
+    - 'lib/proxy_pac_rb/rspec/matchers/base_matcher.rb'
+
+# Offense count: 84
+# This cop supports safe autocorrection (--autocorrect).
 Layout/EmptyLineAfterMagicComment:
   Enabled: false
 
-# Offense count: 87
-# Configuration parameters: EnforcedStyle, SupportedStyles.
+# Offense count: 5
+# Configuration parameters: EnforcedStyle.
 # SupportedStyles: native, lf, crlf
 Layout/EndOfLine:
-  Enabled: false
+  Exclude:
+    - 'Vagrantfile'
+    - 'lib/proxy_pac_rb.rb'
+    - 'lib/proxy_pac_rb/environment.rb'
+    - 'lib/proxy_pac_rb/runtimes.rb'
+    - 'spec/rack/proxy_pac_linter_spec.rb'
 
 # Offense count: 27
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: auto_detection, squiggly, active_support, powerpack, unindent
-Layout/IndentHeredoc:
+# This cop supports safe autocorrection (--autocorrect).
+Layout/HeredocIndentation:
   Exclude:
     - 'lib/proxy_pac_rb/cli/init_proxy_pac.rb'
     - 'lib/proxy_pac_rb/proxy_pac_js.rb'
@@ -34,36 +97,266 @@ Layout/IndentHeredoc:
     - 'spec/rspec/readability_spec.rb'
     - 'spec/rspec/validitiy_spec.rb'
 
-# Offense count: 17
-# Configuration parameters: CountComments, ExcludedMethods.
+# Offense count: 1
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: EnforcedStyle, IndentationWidth.
+# SupportedStyles: aligned, indented
+Layout/LineEndStringConcatenationIndentation:
+  Exclude:
+    - 'lib/proxy_pac_rb/runtimes.rb'
+
+# Offense count: 1
+# This cop supports safe autocorrection (--autocorrect).
+Layout/RescueEnsureAlignment:
+  Exclude:
+    - 'lib/proxy_pac_rb/rspec/helpers.rb'
+
+# Offense count: 1
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: AllowInHeredoc.
+Layout/TrailingWhitespace:
+  Exclude:
+    - '.simplecov'
+
+# Offense count: 4
+# Configuration parameters: AllowedParentClasses.
+Lint/MissingSuper:
+  Exclude:
+    - 'lib/proxy_pac_rb/rspec/matchers/proxy.rb'
+    - 'lib/proxy_pac_rb/runtimes/miniracer.rb'
+    - 'lib/proxy_pac_rb/runtimes/rubyracer.rb'
+    - 'lib/proxy_pac_rb/runtimes/rubyrhino.rb'
+
+# Offense count: 2
+# This cop supports safe autocorrection (--autocorrect).
+Lint/RedundantCopDisableDirective:
+  Exclude:
+    - 'lib/proxy_pac_rb/environment.rb'
+    - 'lib/proxy_pac_rb/javascript.rb'
+
+# Offense count: 1
+# This cop supports unsafe autocorrection (--autocorrect-all).
+Lint/RedundantRequireStatement:
+  Exclude:
+    - 'lib/proxy_pac_rb.rb'
+
+# Offense count: 1
+# This cop supports safe autocorrection (--autocorrect).
+Lint/SendWithMixinArgument:
+  Exclude:
+    - 'Rakefile'
+
+# Offense count: 1
+# Configuration parameters: AllowComments, AllowNil.
+Lint/SuppressedException:
+  Exclude:
+    - 'lib/proxy_pac_rb/environment.rb'
+
+# Offense count: 1
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: strict, consistent
+Lint/SymbolConversion:
+  Exclude:
+    - 'lib/proxy_pac_rb/basic_configuration.rb'
+
+# Offense count: 18
+# Configuration parameters: CountComments, CountAsOne, AllowedMethods, AllowedPatterns.
+# AllowedMethods: refine
 Metrics/BlockLength:
   Max: 178
 
+# Offense count: 4
+# Configuration parameters: AllowedMethods, AllowedPatterns.
+Metrics/CyclomaticComplexity:
+  Max: 9
+
+# Offense count: 1
+# Configuration parameters: AllowedMethods, AllowedPatterns, Max.
+Metrics/PerceivedComplexity:
+  Exclude:
+    - 'lib/proxy_pac_rb/runtimes/miniracer.rb'
+
+# Offense count: 3
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: EnforcedStyle, BlockForwardingName.
+# SupportedStyles: anonymous, explicit
+Naming/BlockForwarding:
+  Exclude:
+    - 'lib/proxy_pac_rb/javascript.rb'
+    - 'lib/proxy_pac_rb/rspec.rb'
+
+# Offense count: 47
+# Configuration parameters: ForbiddenDelimiters.
+# ForbiddenDelimiters: (?i-mx:(^|\s)(EO[A-Z]{1}|END)(\s|$))
+Naming/HeredocDelimiterNaming:
+  Exclude:
+    - 'lib/proxy_pac_rb/cli/init_proxy_pac.rb'
+    - 'lib/proxy_pac_rb/proxy_pac_js.rb'
+    - 'spec/api/proxy_pac_compressor_spec.rb'
+    - 'spec/api/proxy_pac_dumper_spec.rb'
+    - 'spec/api/proxy_pac_file_spec.rb'
+    - 'spec/api/proxy_pac_linter_spec.rb'
+    - 'spec/api/proxy_pac_loader_spec.rb'
+    - 'spec/api/proxy_pac_parser_spec.rb'
+    - 'spec/parser_spec.rb'
+    - 'spec/rack/proxy_pac_compressor_spec.rb'
+    - 'spec/rack/proxy_pac_linter_spec.rb'
+    - 'spec/rspec/compare_proxy_pac_files_spec.rb'
+    - 'spec/rspec/parse_proxy_pac_spec.rb'
+    - 'spec/rspec/readability_spec.rb'
+    - 'spec/rspec/validitiy_spec.rb'
+
+# Offense count: 1
+# Configuration parameters: MinNameLength, AllowNamesEndingInNumbers, AllowedNames, ForbiddenNames.
+# AllowedNames: as, at, by, cc, db, id, if, in, io, ip, of, on, os, pp, to
+Naming/MethodParameterName:
+  Exclude:
+    - 'lib/proxy_pac_rb/proxy_pac_file.rb'
+
+# Offense count: 8
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: PreferredName.
+Naming/RescuedExceptionsVariableName:
+  Exclude:
+    - 'lib/proxy_pac_rb/cli/find_proxy.rb'
+    - 'lib/proxy_pac_rb/javascript_compiler.rb'
+    - 'lib/proxy_pac_rb/proxy_pac_linter.rb'
+    - 'lib/proxy_pac_rb/proxy_pac_loader.rb'
+    - 'lib/proxy_pac_rb/proxy_pac_parser.rb'
+    - 'lib/proxy_pac_rb/rack/proxy_pac_compressor.rb'
+    - 'lib/proxy_pac_rb/rspec/matchers/base_matcher.rb'
+
+# Offense count: 1
+# Configuration parameters: EnforcedStyle, CheckMethodNames, CheckSymbols, AllowedIdentifiers, AllowedPatterns.
+# SupportedStyles: snake_case, normalcase, non_integer
+# AllowedIdentifiers: capture3, iso8601, rfc1123_date, rfc822, rfc2822, rfc3339, x86_64
+Naming/VariableNumber:
+  Exclude:
+    - 'spec/api/proxy_pac_file_spec.rb'
+
+# Offense count: 14
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: AllowOnlyRestArgument, UseAnonymousForwarding, RedundantRestArgumentNames, RedundantKeywordRestArgumentNames, RedundantBlockArgumentNames.
+# RedundantRestArgumentNames: args, arguments
+# RedundantKeywordRestArgumentNames: kwargs, options, opts
+# RedundantBlockArgumentNames: blk, block, proc
+Style/ArgumentsForwarding:
+  Exclude:
+    - 'lib/proxy_pac_rb/basic_configuration.rb'
+    - 'lib/proxy_pac_rb/parser.rb'
+    - 'lib/proxy_pac_rb/rspec.rb'
+    - 'lib/proxy_pac_rb/runtimes/rubyracer.rb'
+    - 'lib/proxy_pac_rb/runtimes/rubyrhino.rb'
+
 # Offense count: 1
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
+# This cop supports unsafe autocorrection (--autocorrect-all).
+# Configuration parameters: MinBranchesCount.
+Style/CaseLikeIf:
+  Exclude:
+    - 'lib/proxy_pac_rb/runtimes/miniracer.rb'
+
+# Offense count: 7
+Style/DocumentDynamicEvalDefinition:
+  Exclude:
+    - 'lib/proxy_pac_rb/runtimes/miniracer.rb'
+    - 'lib/proxy_pac_rb/runtimes/rubyracer.rb'
+    - 'lib/proxy_pac_rb/runtimes/rubyrhino.rb'
+
+# Offense count: 1
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: AutoCorrect, EnforcedStyle.
 # SupportedStyles: compact, expanded
 Style/EmptyMethod:
   Exclude:
     - 'lib/proxy_pac_rb/runtime.rb'
 
+# Offense count: 32
+# This cop supports safe autocorrection (--autocorrect).
+Style/Encoding:
+  Enabled: false
+
+# Offense count: 2
+# This cop supports safe autocorrection (--autocorrect).
+Style/EvalWithLocation:
+  Exclude:
+    - 'lib/proxy_pac_rb/runtimes/rubyracer.rb'
+    - 'lib/proxy_pac_rb/runtimes/rubyrhino.rb'
+
+# Offense count: 11
+# This cop supports safe autocorrection (--autocorrect).
+Style/ExpandPathArguments:
+  Exclude:
+    - 'bin/pprb'
+    - 'lib/proxy_pac_rb/cli/init_proxy_pac.rb'
+    - 'lib/proxy_pac_rb/main.rb'
+    - 'proxy_pac_rb.gemspec'
+    - 'script/config.ru'
+    - 'script/console'
+    - 'spec/spec_helper.rb'
+    - 'templates/test_framework/rspec/spec_helper.rb'
+
+# Offense count: 2
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: AllowedVars.
+Style/FetchEnvVar:
+  Exclude:
+    - 'lib/proxy_pac_rb/runtimes.rb'
+
+# Offense count: 22
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: MaxUnannotatedPlaceholdersAllowed, AllowedMethods, AllowedPatterns.
+# SupportedStyles: annotated, template, unannotated
+Style/FormatStringToken:
+  EnforcedStyle: unannotated
+
 # Offense count: 1
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-# SupportedStyles: when_needed, always, never
+# This cop supports unsafe autocorrection (--autocorrect-all).
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: always, always_true, never
 Style/FrozenStringLiteralComment:
   Exclude:
-    - 'Vagrantfile'
+    - '**/*.arb'
+    - '.simplecov'
+
+# Offense count: 1
+# This cop supports unsafe autocorrection (--autocorrect-all).
+Style/HashExcept:
+  Exclude:
+    - 'lib/proxy_pac_rb/rspec.rb'
 
 # Offense count: 1
-# Cop supports --auto-correct.
+# This cop supports safe autocorrection (--autocorrect).
+Style/IfUnlessModifier:
+  Exclude:
+    - 'lib/proxy_pac_rb/encoding.rb'
+
+# Offense count: 1
+# This cop supports unsafe autocorrection (--autocorrect-all).
 # Configuration parameters: InverseMethods, InverseBlocks.
 Style/InverseMethods:
   Exclude:
     - 'lib/proxy_pac_rb/rspec.rb'
 
+# Offense count: 2
+# This cop supports unsafe autocorrection (--autocorrect-all).
+Style/MapIntoArray:
+  Exclude:
+    - 'lib/proxy_pac_rb/rack/proxy_pac_compressor.rb'
+    - 'lib/proxy_pac_rb/rack/proxy_pac_linter.rb'
+
+# Offense count: 1
+Style/MissingRespondToMissing:
+  Exclude:
+    - 'lib/proxy_pac_rb/javascript.rb'
+
+# Offense count: 1
+Style/MixinUsage:
+  Exclude:
+    - 'spec/spec_helper.rb'
+
 # Offense count: 7
-# Cop supports --auto-correct.
+# This cop supports safe autocorrection (--autocorrect).
 # Configuration parameters: PreferredDelimiters.
 Style/PercentLiteralDelimiters:
   Exclude:
@@ -74,18 +367,73 @@ Style/PercentLiteralDelimiters:
     - 'spec/environment_spec.rb'
     - 'templates/test_framework/rspec/support/aruba.rb'
 
+# Offense count: 5
+# This cop supports safe autocorrection (--autocorrect).
+Style/RedundantBegin:
+  Exclude:
+    - 'lib/proxy_pac_rb/cli/find_proxy.rb'
+    - 'lib/proxy_pac_rb/environment.rb'
+    - 'lib/proxy_pac_rb/runtimes/rubyracer.rb'
+
+# Offense count: 7
+# This cop supports safe autocorrection (--autocorrect).
+Style/RedundantConstantBase:
+  Exclude:
+    - 'proxy_pac_rb.gemspec'
+    - 'script/console'
+    - 'spec/spec_helper.rb'
+    - 'templates/test_framework/rspec/spec_helper.rb'
+
+# Offense count: 4
+# This cop supports safe autocorrection (--autocorrect).
+Style/RedundantStringEscape:
+  Exclude:
+    - 'spec/api/proxy_pac_compressor_spec.rb'
+    - 'spec/rack/proxy_pac_compressor_spec.rb'
+
+# Offense count: 6
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: implicit, explicit
+Style/RescueStandardError:
+  Exclude:
+    - 'lib/proxy_pac_rb/proxy_pac_linter.rb'
+    - 'lib/proxy_pac_rb/proxy_pac_loader.rb'
+    - 'lib/proxy_pac_rb/proxy_pac_parser.rb'
+    - 'lib/proxy_pac_rb/rack/proxy_pac_compressor.rb'
+    - 'lib/proxy_pac_rb/rspec/helpers.rb'
+    - 'lib/proxy_pac_rb/runtimes/rubyracer.rb'
+
+# Offense count: 11
+# This cop supports safe autocorrection (--autocorrect).
+Style/StderrPuts:
+  Exclude:
+    - 'lib/proxy_pac_rb/cli/compress_proxy_pac.rb'
+    - 'lib/proxy_pac_rb/cli/find_proxy.rb'
+    - 'lib/proxy_pac_rb/cli/lint_proxy_pac.rb'
+    - 'lib/proxy_pac_rb/cli/show.rb'
+    - 'lib/proxy_pac_rb/cli_validator.rb'
+    - 'lib/proxy_pac_rb/parser.rb'
+
+# Offense count: 6
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: EnforcedStyle, ConsistentQuotesInMultiline.
+# SupportedStyles: single_quotes, double_quotes
+Style/StringLiterals:
+  Exclude:
+    - '.simplecov'
+
 # Offense count: 2
-# Cop supports --auto-correct.
-# Configuration parameters: MinSize, SupportedStyles.
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: MinSize.
 # SupportedStyles: percent, brackets
 Style/SymbolArray:
   EnforcedStyle: brackets
 
-# Offense count: 4
-# Cop supports --auto-correct.
-Style/YodaCondition:
+# Offense count: 1
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: EnforcedStyleForMultiline.
+# SupportedStylesForMultiline: comma, consistent_comma, no_comma
+Style/TrailingCommaInHashLiteral:
   Exclude:
-    - 'lib/proxy_pac_rb/proxy_pac_file.rb'
-    - 'lib/proxy_pac_rb/rack/proxy_pac_compressor.rb'
-    - 'lib/proxy_pac_rb/rack/proxy_pac_linter.rb'
-    - 'lib/proxy_pac_rb/rspec/helpers.rb'
+    - 'lib/proxy_pac_rb/proxy_pac_compressor.rb'
diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000..47b322c
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+3.4.1
diff --git a/Gemfile b/Gemfile
index ed7218c..807996d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -13,15 +13,15 @@ group :debug do
 end
 
 group :development, :test do
-  gem 'middleman', '~> 4.1', require: false
-  gem 'aruba', '~>0.14.2', require: false
+  gem 'middleman', require: false
+  gem 'aruba', require: false
   gem 'awesome_print', require: 'ap'
-  gem 'bundler', '~> 1.3', require: false
+  gem 'bundler', require: false
   gem 'command_exec', require: false
   gem 'coveralls', require: false
   gem 'cucumber', require: false
   gem 'erubis'
-  gem 'fedux_org-stdlib', '~>0.11.17', require: false
+  gem 'fedux_org-stdlib', require: false
   gem 'filegen'
   gem 'foreman', require: false
   gem 'fuubar', require: false
@@ -49,11 +49,18 @@ group :profile do
 end
 
 group :runtimes do
-  group :therubyracer do
-    gem 'therubyracer', require: 'v8'
+  # mini_racer & therubyracer can't sit in the same gemfile
+  # uncomment the needed one and comment the other
+  #
+  group :mini_racer do
+    gem 'mini_racer', require: 'mini_racer'
   end
 
+  # group :therubyracer do
+  #   gem 'therubyracer', require: 'v8'
+  # end
+
   group :therubyrhino do
-    gem 'therubyrhino', require: 'rhino'
+    gem 'therubyrhino', require: 'rhino', platform: :jruby
   end
 end
diff --git a/README.md b/README.md
index 25e2c1f..ed100ba 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,9 @@
 [![Downloads](http://img.shields.io/gem/dt/proxy_pac_rb.svg?style=flat)](http://rubygems.org/gems/proxy_pac_rb)
 
 
-`proxy_pac_rb` is a gem to compress, lint and parse [proxy auto-config](http://en.wikipedia.org/wiki/Proxy_auto-config) files. It comes with a cli program, some rack middlewares and can be used from within ruby scripts as well. `proxy_pac_rb` uses a JavaScript runtime to evaulate a proxy auto-config file the same way a browser does to determine what proxy (if any at all) should a program use to connect to a server. You must install on of the supported JavaScript runtimes: [therubyracer](https://rubygems.org/gems/therubyracer) or [therubyrhino](https://rubygems.org/gems/therubyrhino/).
+`proxy_pac_rb` is a gem to compress, lint and parse [proxy auto-config](http://en.wikipedia.org/wiki/Proxy_auto-config
+) files. It comes with a cli program, some rack middlewares and can be used from within ruby scripts as well
+. `proxy_pac_rb` uses a JavaScript runtime to evaulate a proxy auto-config file the same way a browser does to determine what proxy (if any at all) should a program use to connect to a server. You must install on of the supported JavaScript runtimes: [miniracer](https://github.com/rubyjs/mini_racer), [therubyracer](https://rubygems.org/gems/therubyracer) or [therubyrhino](https://rubygems.org/gems/therubyrhino/).
 
 Big thanks to [sstephenson](https://github.com/sstephenson)'s [execjs](https://github.com/sstephenson/execjs) for the
 runtime wrapper code and to
@@ -35,6 +37,7 @@ After installing the `proxy_pac_rb` gem you must install a JavaScript runtime. C
 
 * [therubyracer](https://rubygems.org/gems/therubyracer) Google V8 embedded within Ruby
 * [therubyrhino](https://rubygems.org/gems/therubyrhino/) Mozilla Rhino embedded within JRuby
+* [miniracer](https://github.com/rubyjs/mini_racer) Minimal, modern embedded V8 for Ruby
 
 ## Usage
 
diff --git a/Vagrantfile b/Vagrantfile
new file mode 100644
index 0000000..f707086
--- /dev/null
+++ b/Vagrantfile
@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+# -*- mode: ruby -*-
+# vi: set ft=ruby :
+
+RUBY_V = File.read('./.ruby-version').chomp
+Vagrant.configure('2') do |config|
+  config.vm.box = 'bento/debian-12'
+  config.vm.network 'forwarded_port', guest: 3000, host: 3033, host_ip: 'localhost'
+  # change to 'virtualbox' if you use it in place of vmware
+  config.vm.provider 'vmware_desktop' do |vb|
+    vb.memory = '1024'
+    vb.gui = false
+  end
+  config.vm.provision 'shell', inline: <<-SHELL
+    # for nodejs repository
+    # see https://github.com/nodesource/distributions#debian-and-ubuntu-based-distributions
+    sudo apt-get install -y ca-certificates curl gnupg
+    NODE_MAJOR=22
+    curl -fsSL https://deb.nodesource.com/setup_$NODE_MAJOR.x -o nodesource_setup.sh
+    sudo -E bash nodesource_setup.sh
+    # update the apt repositories
+    sudo apt-get update
+    # update the system
+    sudo apt-get -y dist-upgrade
+    # install ruby prerequisite
+    sudo apt-get install -y git-core curl zlib1g-dev build-essential libssl-dev libreadline-dev \
+                            libyaml-dev libsqlite3-dev sqlite3 libxml2-dev libxslt1-dev \
+                            libcurl4-openssl-dev libffi-dev \
+                            nodejs yarn
+    # cleanup
+    sudo apt-get autoremove -y
+    sudo apt-get clean -y
+  SHELL
+
+  config.vm.provision :shell, privileged: false, inline: <<~SCRIPT
+    if [ ! -d ~/.rbenv ]; then
+      git clone https://github.com/rbenv/rbenv.git ~/.rbenv
+      echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
+      echo 'eval "$(rbenv init -)"' >> ~/.bashrc
+    fi
+    git -C /home/vagrant/.rbenv pull
+
+    if [ ! -d ~/.rbenv/plugins/ruby-build ]; then
+      git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build
+      echo 'export PATH="$HOME/.rbenv/plugins/ruby-build/bin:$PATH"' >> ~/.bashrc
+    fi
+    git -C /home/vagrant/.rbenv/plugins/ruby-build pull
+    export PATH="$HOME/.rbenv/bin:$PATH"
+    export PATH="$HOME/.rbenv/plugins/ruby-build/bin:$PATH"
+
+    eval "$(rbenv init -)"
+    if [ ! -e .rbenv/versions/#{RUBY_V} ]; then
+      rbenv install #{RUBY_V}
+      rbenv global #{RUBY_V}
+      gem update --system --no-doc
+      rbenv rehash
+    fi
+    cd /vagrant
+    # if [ ! -e /home/vagrant/.rbenv/shims/bundle ]; then
+      gem update --system --no-doc
+      rbenv rehash
+    # fi
+    bundle install
+  SCRIPT
+end
diff --git a/lib/proxy_pac_rb.rb b/lib/proxy_pac_rb.rb
index 7920d02..ffa31d5 100644
--- a/lib/proxy_pac_rb.rb
+++ b/lib/proxy_pac_rb.rb
@@ -28,6 +28,7 @@
 require 'proxy_pac_rb/runtime'
 require 'proxy_pac_rb/runtimes/rubyracer'
 require 'proxy_pac_rb/runtimes/rubyrhino'
+require 'proxy_pac_rb/runtimes/miniracer'
 require 'proxy_pac_rb/runtimes'
 require 'proxy_pac_rb/parser'
 require 'proxy_pac_rb/javascript'
diff --git a/lib/proxy_pac_rb/rspec/matchers/base_matcher.rb b/lib/proxy_pac_rb/rspec/matchers/base_matcher.rb
index 15412fd..07a88e8 100644
--- a/lib/proxy_pac_rb/rspec/matchers/base_matcher.rb
+++ b/lib/proxy_pac_rb/rspec/matchers/base_matcher.rb
@@ -166,14 +166,14 @@ def failure_message_when_negated
         end
 
         # @private
-        # rubocop:disable Style/PredicateName
+        # rubocop:disable Naming/PredicateName
         def self.has_default_failure_messages?(matcher)
           matcher.method(:failure_message).owner == self &&
             matcher.method(:failure_message_when_negated).owner == self
         rescue NameError
           false
         end
-        # rubocop:enable Style/PredicateName
+        # rubocop:enable Naming/PredicateName
       end
 
       include DefaultFailureMessages
diff --git a/lib/proxy_pac_rb/runtimes.rb b/lib/proxy_pac_rb/runtimes.rb
index 77ba0b4..cbe252b 100644
--- a/lib/proxy_pac_rb/runtimes.rb
+++ b/lib/proxy_pac_rb/runtimes.rb
@@ -2,6 +2,7 @@
 module ProxyPacRb
   # JavaScript Runtimes
   module Runtimes
+    MiniRacer = MiniRacerRuntime.new
     RubyRacer = RubyRacerRuntime.new
     RubyRhino = RubyRhinoRuntime.new
 
@@ -33,6 +34,7 @@ def names
 
       def runtimes
         @runtimes ||= [
+          MiniRacer,
           RubyRacer,
           RubyRhino
         ]
diff --git a/lib/proxy_pac_rb/runtimes/miniracer.rb b/lib/proxy_pac_rb/runtimes/miniracer.rb
new file mode 100644
index 0000000..3900208
--- /dev/null
+++ b/lib/proxy_pac_rb/runtimes/miniracer.rb
@@ -0,0 +1,104 @@
+# frozen_string_literal: true
+module ProxyPacRb
+  # Mini Racer Runtime
+  # little adaptation from execjs gem.
+  # All credits go to execjs gem author
+  class MiniRacerRuntime < Runtime
+    # Context
+    class Context < Runtime::Context
+      def initialize(_runtime, source = '', _environment = nil)
+        source = encode(source)
+
+        self.context = ::MiniRacer::Context.new
+        translate { context.eval(source) }
+      end
+
+      def include(environment)
+        environment.available_methods.each do |name|
+          context.attach(name.to_s, environment.method(name))
+        end
+      end
+
+      def exec(source, options = {})
+        source = encode(source)
+
+        # rubocop:disable Security/Eval, Style/EvalWithLocation
+        eval "(function(){#{source}})()", options if /\S/ =~ source
+        # rubocop:enable Security/Eval, Style/EvalWithLocation
+      end
+
+      def eval(source, _options = {})
+        source = encode(source)
+
+        return nil unless /\S/ =~ source
+
+        translate { context.eval("(#{source})") }
+      end
+
+      def call(properties, *args)
+        translate { context.eval("#{properties}.apply(this, #{::JSON.generate(args)})") }
+      end
+
+      private
+
+      def strip_functions!(value)
+        if Array === value
+          value.map! do |v|
+            if MiniRacer::JavaScriptFunction === value
+              nil
+            else
+              strip_functions!(v)
+            end
+          end
+        elsif Hash === value
+          value.each do |k, v|
+            if MiniRacer::JavaScriptFunction === v
+              value.delete k
+            else
+              value[k] = strip_functions!(v)
+            end
+          end
+          value
+        elsif MiniRacer::JavaScriptFunction === value
+          nil
+        else
+          value
+        end
+      end
+
+      def translate
+        strip_functions! yield
+      rescue MiniRacer::RuntimeError => e
+        ex = ProgramError.new e.message
+        if backtrace = e.backtrace # rubocop:disable Lint/AssignmentInCondition
+          backtrace = backtrace.map do |line|
+            if line =~ /JavaScript at/
+              line.sub('JavaScript at ', '')
+                  .sub('<anonymous>', '(proxypac)')
+                  .strip
+            else
+              line
+            end
+          end
+          ex.set_backtrace backtrace
+        end
+        raise ex
+      rescue MiniRacer::ParseError => e
+        ex = RuntimeError.new e.message
+        ex.set_backtrace(['(proxypac):1'] + e.backtrace)
+        raise ex
+      end
+    end
+
+    def name
+      'mini_racer (V8)'
+    end
+
+    def available?
+      require 'mini_racer'
+      true
+    rescue LoadError
+      false
+    end
+  end
+end
diff --git a/proxy_pac_rb.gemspec b/proxy_pac_rb.gemspec
index e9187f0..ce3490d 100644
--- a/proxy_pac_rb.gemspec
+++ b/proxy_pac_rb.gemspec
@@ -11,7 +11,7 @@ Gem::Specification.new do |spec|
   spec.homepage    = 'https://github.com/dg-vrnetze/proxy_pac_rb'
   spec.summary     = 'Compress, lint and parse proxy auto-config files from commandline, rack-compatible applications and custom ruby code.'
   spec.description = <<-DESC
-"proxy_pac_rb" is a gem to compress, lint and parse proxy auto-config files. It comes with a cli program, some rack middlewares and can be used from within ruby scripts as well. "proxy_pac_rb" uses a JavaScript runtime to evaulate a proxy auto-config file the same way a browser does to determine what proxy (if any at all) should a program use to connect to a server. You must install on of the supported JavaScript runtimes: therubyracer or therubyrhino
+"proxy_pac_rb" is a gem to compress, lint and parse proxy auto-config files. It comes with a cli program, some rack middlewares and can be used from within ruby scripts as well. "proxy_pac_rb" uses a JavaScript runtime to evaulate a proxy auto-config file the same way a browser does to determine what proxy (if any at all) should a program use to connect to a server. You must install on of the supported JavaScript runtimes: miniracer, therubyracer or therubyrhino
 DESC
 
   spec.license       = 'MIT'
@@ -21,12 +21,12 @@ DESC
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ['lib']
 
-  spec.add_runtime_dependency 'addressable', '~>2.3'
-  spec.add_runtime_dependency 'activesupport', '>=4.1', '<5.2'
+  spec.add_runtime_dependency 'addressable'
+  spec.add_runtime_dependency 'activesupport', '>=4.1'
   spec.add_runtime_dependency 'uglifier', '>= 2.7.1'
-  spec.add_runtime_dependency 'excon', '~> 0.45.3'
-  spec.add_runtime_dependency 'contracts', '~> 0.9'
-  spec.add_runtime_dependency 'thor', '~> 0.19'
+  spec.add_runtime_dependency 'excon'
+  spec.add_runtime_dependency 'contracts'
+  spec.add_runtime_dependency 'thor'
 
-  spec.required_ruby_version = '~> 2.3'
+  spec.required_ruby_version = '>= 2.3'
 end
diff --git a/spec/rack/proxy_pac_compressor_spec.rb b/spec/rack/proxy_pac_compressor_spec.rb
index 3c054d7..45bcbc2 100644
--- a/spec/rack/proxy_pac_compressor_spec.rb
+++ b/spec/rack/proxy_pac_compressor_spec.rb
@@ -37,7 +37,7 @@
   end
 
   context 'when invalid proxy pac is given' do
-    let(:compressed_content) { %{Unexpected token: string (§$ )} }
+    let(:compressed_content) { %{Unexpected token: string (!$ )} }
 
     let(:app) do
       a = Class.new(Sinatra::Base) do
@@ -48,7 +48,7 @@
         get '/' do
           <<~EOS.chomp
           function FindProxyForURL(url, host) {
-            return $"§$ "DIRECT";
+            return $"!$ "DIRECT";
           }
           EOS
         end