diff --git a/Gemfile b/Gemfile
index 56d286ac..099de8f3 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,10 +10,10 @@ gemspec
 # Git. Remember to move these dependencies to your gemspec before releasing
 # your gem to rubygems.org.
 
-gem "rails", ">= 5.2.4.6", "< 6.2"
+gem 'rails', '>= 5.2.4.6', '< 6.2'
 
 group :development, :test do
-  gem 'rubocop'
   gem 'pry'
   gem 'pry-nav'
+  gem 'rubocop'
 end
diff --git a/Rakefile b/Rakefile
index 435cbb33..a243ca4d 100644
--- a/Rakefile
+++ b/Rakefile
@@ -14,21 +14,19 @@ RDoc::Task.new(:rdoc) do |rdoc|
   rdoc.rdoc_files.include('lib/**/*.rb')
 end
 
-APP_RAKEFILE = File.expand_path("../spec/dummy/Rakefile", __FILE__)
+APP_RAKEFILE = File.expand_path('spec/dummy/Rakefile', __dir__)
 load 'rails/tasks/engine.rake'
 
-
 load 'rails/tasks/statistics.rake'
 
-
 Bundler::GemHelper.install_tasks
 
-Dir[File.join(File.dirname(__FILE__), 'tasks/**/*.rake')].each {|f| load f }
+Dir[File.join(File.dirname(__FILE__), 'tasks/**/*.rake')].each { |f| load f }
 
 require 'rspec/core'
 require 'rspec/core/rake_task'
 
-desc "Run all specs in spec directory (excluding plugin specs)"
-RSpec::Core::RakeTask.new(:spec => 'app:db:test:prepare')
+desc 'Run all specs in spec directory (excluding plugin specs)'
+RSpec::Core::RakeTask.new(spec: 'app:db:test:prepare')
 
-task :default => :spec
+task default: :spec
diff --git a/app/controllers/concerns/scim_rails/response.rb b/app/controllers/concerns/scim_rails/response.rb
index 00bbbe67..7dea99f8 100644
--- a/app/controllers/concerns/scim_rails/response.rb
+++ b/app/controllers/concerns/scim_rails/response.rb
@@ -2,7 +2,7 @@
 
 module ScimRails
   module Response
-    CONTENT_TYPE = "application/scim+json"
+    CONTENT_TYPE = 'application/scim+json'
 
     def json_response(object, status = :ok)
       render \
@@ -13,12 +13,12 @@ def json_response(object, status = :ok)
 
     def json_scim_response(object:, status: :ok, counts: nil)
       case params[:action]
-      when "index"
+      when 'index'
         render \
           json: list_response(object, counts),
           status: status,
           content_type: CONTENT_TYPE
-      when "show", "create", "put_update", "patch_update"
+      when 'show', 'create', 'put_update', 'patch_update'
         render \
           json: object_response(object),
           status: status,
@@ -28,67 +28,67 @@ def json_scim_response(object:, status: :ok, counts: nil)
 
     private
 
-    def list_response(object, counts)
-      object = object
-        .order(:id)
-        .offset(counts.offset)
-        .limit(counts.limit)
-      {
-        schemas: [
-          "urn:ietf:params:scim:api:messages:2.0:ListResponse"
-        ],
-        totalResults: counts.total,
-        startIndex: counts.start_index,
-        itemsPerPage: counts.limit,
-        Resources: list_objects(object)
-      }
-    end
+      def list_response(object, counts)
+        object = object
+                 .order(:id)
+                 .offset(counts.offset)
+                 .limit(counts.limit)
+        {
+          schemas: [
+            'urn:ietf:params:scim:api:messages:2.0:ListResponse'
+          ],
+          totalResults: counts.total,
+          startIndex: counts.start_index,
+          itemsPerPage: counts.limit,
+          Resources: list_objects(object),
+        }
+      end
 
-    def list_objects(objects)
-      objects.map do |object|
-        object_response(object)
+      def list_objects(objects)
+        objects.map do |object|
+          object_response(object)
+        end
       end
-    end
 
-    def object_response(object)
-      schema = case object
-               when ScimRails.config.scim_users_model
-                 ScimRails.config.user_schema
-               when ScimRails.config.scim_groups_model
-                 ScimRails.config.group_schema
-               else
-                 raise ScimRails::ExceptionHandler::InvalidQuery,
-                       "Unknown model: #{object}"
-               end
-      find_value(object, schema)
-    end
+      def object_response(object)
+        schema = case object
+                 when ScimRails.config.scim_users_model
+                   ScimRails.config.user_schema
+                 when ScimRails.config.scim_groups_model
+                   ScimRails.config.group_schema
+                 else
+                   raise ScimRails::ExceptionHandler::InvalidQuery,
+                         "Unknown model: #{object}"
+                 end
+        find_value(object, schema)
+      end
 
-    # `find_value` is a recursive method that takes a "user" and a
-    # "user schema" and replaces any symbols in the schema with the
-    # corresponding value from the user. Given a schema with symbols,
-    # `find_value` will search through the object for the symbols,
-    # send those symbols to the model, and replace the symbol with
-    # the return value.
+      # `find_value` is a recursive method that takes a "user" and a
+      # "user schema" and replaces any symbols in the schema with the
+      # corresponding value from the user. Given a schema with symbols,
+      # `find_value` will search through the object for the symbols,
+      # send those symbols to the model, and replace the symbol with
+      # the return value.
 
-    def find_value(object, schema)
-      case schema
-      when Hash
-        schema.each.with_object({}) do |(key, value), hash|
-          hash[key] = find_value(object, value)
+      def find_value(object, schema)
+        case schema
+        when Hash
+          schema.each.with_object({}) do |(key, value), hash|
+            hash[key] = find_value(object, value)
+          end
+        when Array, ActiveRecord::Associations::CollectionProxy
+          schema.map do |value|
+            find_value(object, value)
+          end
+        when ScimRails.config.scim_users_model
+          find_value(schema, ScimRails.config.user_abbreviated_schema)
+        when ScimRails.config.scim_groups_model
+          find_value(schema, ScimRails.config.group_abbreviated_schema)
+        when Symbol
+          find_value(object, object.public_send(schema))
+        else
+          schema
         end
-      when Array, ActiveRecord::Associations::CollectionProxy
-        schema.map do |value|
-          find_value(object, value)
-        end
-      when ScimRails.config.scim_users_model
-        find_value(schema, ScimRails.config.user_abbreviated_schema)
-      when ScimRails.config.scim_groups_model
-        find_value(schema, ScimRails.config.group_abbreviated_schema)
-      when Symbol
-        find_value(object, object.public_send(schema))
-      else
-        schema
       end
-    end
   end
 end
diff --git a/app/controllers/scim_rails/application_controller.rb b/app/controllers/scim_rails/application_controller.rb
index f9340d5c..7cde4a8f 100644
--- a/app/controllers/scim_rails/application_controller.rb
+++ b/app/controllers/scim_rails/application_controller.rb
@@ -10,63 +10,63 @@ class ApplicationController < ActionController::API
 
     private
 
-    def authorize_request
-      send(authentication_strategy) do |searchable_attribute, authentication_attribute|
-        authorization = AuthorizeApiRequest.new(
-          searchable_attribute: searchable_attribute,
-          authentication_attribute: authentication_attribute
-        )
-        @company = authorization.company
+      def authorize_request
+        send(authentication_strategy) do |searchable_attribute, authentication_attribute|
+          authorization = AuthorizeApiRequest.new(
+            searchable_attribute: searchable_attribute,
+            authentication_attribute: authentication_attribute
+          )
+          @company = authorization.company
+        end
+        raise ScimRails::ExceptionHandler::InvalidCredentials if @company.blank?
       end
-      raise ScimRails::ExceptionHandler::InvalidCredentials if @company.blank?
-    end
 
-    def authentication_strategy
-      if request.headers["Authorization"]&.include?("Bearer")
-        :authenticate_with_oauth_bearer
-      else
-        :authenticate_with_http_basic
+      def authentication_strategy
+        if request.headers['Authorization']&.include?('Bearer')
+          :authenticate_with_oauth_bearer
+        else
+          :authenticate_with_http_basic
+        end
       end
-    end
 
-    def authenticate_with_oauth_bearer
-      authentication_attribute = request.headers["Authorization"].split.last
-      payload = ScimRails::Encoder.decode(authentication_attribute).with_indifferent_access
-      searchable_attribute = payload[ScimRails.config.basic_auth_model_searchable_attribute]
+      def authenticate_with_oauth_bearer
+        authentication_attribute = request.headers['Authorization'].split.last
+        payload = ScimRails::Encoder.decode(authentication_attribute).with_indifferent_access
+        searchable_attribute = payload[ScimRails.config.basic_auth_model_searchable_attribute]
 
-      yield searchable_attribute, authentication_attribute
-    end
+        yield searchable_attribute, authentication_attribute
+      end
 
-    def find_value_for(attribute)
-      params.dig(*path_for(attribute))
-    end
+      def find_value_for(attribute)
+        params.dig(*path_for(attribute))
+      end
 
-    # `path_for` is a recursive method used to find the "path" for
-    # `.dig` to take when looking for a given attribute in the
-    # params.
-    #
-    # Example: `path_for(:name)` should return an array that looks
-    # like [:names, 0, :givenName]. `.dig` can then use that path
-    # against the params to translate the :name attribute to "John".
+      # `path_for` is a recursive method used to find the "path" for
+      # `.dig` to take when looking for a given attribute in the
+      # params.
+      #
+      # Example: `path_for(:name)` should return an array that looks
+      # like [:names, 0, :givenName]. `.dig` can then use that path
+      # against the params to translate the :name attribute to "John".
 
-    def path_for(attribute, object = controller_schema, path = [])
-      at_path = path.empty? ? object : object.dig(*path)
-      return path if at_path == attribute
+      def path_for(attribute, object = controller_schema, path = [])
+        at_path = path.empty? ? object : object.dig(*path)
+        return path if at_path == attribute
 
-      case at_path
-      when Hash
-        at_path.each do |key, _value|
-          found_path = path_for(attribute, object, [*path, key])
-          return found_path if found_path
-        end
-        nil
-      when Array
-        at_path.each_with_index do |_value, index|
-          found_path = path_for(attribute, object, [*path, index])
-          return found_path if found_path
+        case at_path
+        when Hash
+          at_path.each do |key, _value|
+            found_path = path_for(attribute, object, [*path, key])
+            return found_path if found_path
+          end
+          nil
+        when Array
+          at_path.each_with_index do |_value, index|
+            found_path = path_for(attribute, object, [*path, index])
+            return found_path if found_path
+          end
+          nil
         end
-        nil
       end
-    end
   end
 end
diff --git a/app/controllers/scim_rails/scim_groups_controller.rb b/app/controllers/scim_rails/scim_groups_controller.rb
index b9359f31..ce71c8f5 100644
--- a/app/controllers/scim_rails/scim_groups_controller.rb
+++ b/app/controllers/scim_rails/scim_groups_controller.rb
@@ -82,7 +82,7 @@ def destroy
         raise ScimRails::ExceptionHandler::InvalidConfiguration, e.message
       rescue ActiveRecord::RecordNotDestroyed => e
         raise ScimRails::ExceptionHandler::InvalidRequest, e.message
-      rescue => e
+      rescue StandardError => e
         raise ScimRails::ExceptionHandler::UnexpectedError, e.message
       end
 
diff --git a/app/controllers/scim_rails/scim_users_controller.rb b/app/controllers/scim_rails/scim_users_controller.rb
index 86c0b50e..6cac985c 100644
--- a/app/controllers/scim_rails/scim_users_controller.rb
+++ b/app/controllers/scim_rails/scim_users_controller.rb
@@ -82,7 +82,7 @@ def destroy
         raise ScimRails::ExceptionHandler::InvalidConfiguration, e.message
       rescue ActiveRecord::RecordNotDestroyed => e
         raise ScimRails::ExceptionHandler::InvalidRequest, e.message
-      rescue => e
+      rescue StandardError => e
         raise ScimRails::ExceptionHandler::UnexpectedError, e.message
       end
 
diff --git a/app/models/scim_rails/authorize_api_request.rb b/app/models/scim_rails/authorize_api_request.rb
index d9cde04e..68521f58 100644
--- a/app/models/scim_rails/authorize_api_request.rb
+++ b/app/models/scim_rails/authorize_api_request.rb
@@ -5,7 +5,9 @@ def initialize(searchable_attribute:, authentication_attribute:)
       @searchable_attribute = searchable_attribute
       @authentication_attribute = authentication_attribute
 
-      raise ScimRails::ExceptionHandler::InvalidCredentials if searchable_attribute.blank? || authentication_attribute.blank?
+      if searchable_attribute.blank? || authentication_attribute.blank?
+        raise ScimRails::ExceptionHandler::InvalidCredentials
+      end
 
       @search_parameter = { ScimRails.config.basic_auth_model_searchable_attribute => @searchable_attribute }
     end
@@ -18,23 +20,20 @@ def company
 
     private
 
-    attr_reader :authentication_attribute
-    attr_reader :search_parameter
-    attr_reader :searchable_attribute
-
-    def find_company
-      @company ||= ScimRails.config.basic_auth_model.find_by!(search_parameter)
-
-    rescue ActiveRecord::RecordNotFound
-      raise ScimRails::ExceptionHandler::InvalidCredentials
-    end
-
-    def authorize(authentication_model)
-      authorized = ActiveSupport::SecurityUtils.secure_compare(
-        authentication_model.public_send(ScimRails.config.basic_auth_model_authenticatable_attribute),
-        authentication_attribute
-      )
-      raise ScimRails::ExceptionHandler::InvalidCredentials unless authorized
-    end
+      attr_reader :authentication_attribute, :search_parameter, :searchable_attribute
+
+      def find_company
+        @company ||= ScimRails.config.basic_auth_model.find_by!(search_parameter)
+      rescue ActiveRecord::RecordNotFound
+        raise ScimRails::ExceptionHandler::InvalidCredentials
+      end
+
+      def authorize(authentication_model)
+        authorized = ActiveSupport::SecurityUtils.secure_compare(
+          authentication_model.public_send(ScimRails.config.basic_auth_model_authenticatable_attribute),
+          authentication_attribute
+        )
+        raise ScimRails::ExceptionHandler::InvalidCredentials unless authorized
+      end
   end
 end
diff --git a/app/models/scim_rails/scim_count.rb b/app/models/scim_rails/scim_count.rb
index f8c91754..73143a2c 100644
--- a/app/models/scim_rails/scim_count.rb
+++ b/app/models/scim_rails/scim_count.rb
@@ -10,17 +10,21 @@ class ScimCount
 
     def limit
       return 100 if @limit.blank?
+
       validate_numericality(@limit)
       input = @limit.to_i
       raise if input < 1
+
       input
     end
 
     def start_index
       return 1 if @start_index.blank?
+
       validate_numericality(@start_index)
       input = @start_index.to_i
       return 1 if input < 1
+
       input
     end
 
@@ -30,9 +34,9 @@ def offset
 
     private
 
-    def validate_numericality(input)
-      raise unless input.match?(/\A\d+\z/)
-    end
+      def validate_numericality(input)
+        raise unless input.match?(/\A\d+\z/)
+      end
 
   end
 end
diff --git a/app/models/scim_rails/scim_query_parser.rb b/app/models/scim_rails/scim_query_parser.rb
index 13059610..df593462 100644
--- a/app/models/scim_rails/scim_query_parser.rb
+++ b/app/models/scim_rails/scim_query_parser.rb
@@ -5,7 +5,7 @@ class ScimQueryParser
     attr_accessor :query_elements, :query_attributes
 
     def initialize(query_string, queryable_attributes)
-      self.query_elements = query_string.gsub(/\[(.+?)\]/, ".0").split
+      self.query_elements = query_string.gsub(/\[(.+?)\]/, '.0').split
       self.query_attributes = queryable_attributes
     end
 
@@ -13,8 +13,8 @@ def attribute
       attribute = query_elements[0]
       raise ScimRails::ExceptionHandler::InvalidQuery if attribute.blank?
 
-      dig_keys = attribute.split(".").map do |step|
-        step == "0" ? 0 : step.to_sym
+      dig_keys = attribute.split('.').map do |step|
+        step == '0' ? 0 : step.to_sym
       end
 
       mapped_attribute = query_attributes.dig(*dig_keys)
@@ -28,22 +28,22 @@ def operator
     end
 
     def parameter
-      parameter = query_elements[2..-1].join(" ")
+      parameter = query_elements[2..-1].join(' ')
       return if parameter.blank?
 
-      parameter.gsub(/"/, "")
+      parameter.gsub(/"/, '')
     end
 
     private
 
-    def sql_comparison_operator(element)
-      case element
-      when "eq"
-        "="
-      else
-        # TODO: implement additional query filters
-        raise ScimRails::ExceptionHandler::InvalidQuery
+      def sql_comparison_operator(element)
+        case element
+        when 'eq'
+          '='
+        else
+          # TODO: implement additional query filters
+          raise ScimRails::ExceptionHandler::InvalidQuery
+        end
       end
-    end
   end
 end
diff --git a/lib/generators/scim_rails/templates/initializer.rb b/lib/generators/scim_rails/templates/initializer.rb
index 0e74b2fb..73f1738a 100644
--- a/lib/generators/scim_rails/templates/initializer.rb
+++ b/lib/generators/scim_rails/templates/initializer.rb
@@ -2,7 +2,7 @@
 
 ScimRails.configure do |config|
   # Model used for authenticating and scoping users.
-  config.basic_auth_model = "Company"
+  config.basic_auth_model = 'Company'
 
   # Attribute used to search for a given record. This
   # attribute should be unique as it will return the
@@ -14,7 +14,7 @@
   config.basic_auth_model_authenticatable_attribute = :api_token
 
   # Model used for user records.
-  config.scim_users_model = "User"
+  config.scim_users_model = 'User'
 
   # Method used for retrieving user records from the
   # authenticatable model.
@@ -25,7 +25,7 @@
   config.scim_user_prevent_update_on_create = false
 
   # Model used for group records.
-  config.scim_groups_model = "Group"
+  config.scim_groups_model = 'Group'
   # Method used for retrieving user records from the
   # authenticatable model.
   config.scim_groups_scope = :groups
@@ -56,16 +56,16 @@
     userName: :email,
     givenName: :first_name,
     familyName: :last_name,
-    email: :email
+    email: :email,
   }
 
   # Array of attributes that can be modified on the
   # user model. If the attribute is not in this array
   # the attribute cannot be modified by this Gem.
-  config.mutable_user_attributes = [
-    :first_name,
-    :last_name,
-    :email
+  config.mutable_user_attributes = %i[
+    first_name
+    last_name
+    email
   ]
 
   # Hash of mutable attributes. This object is the map
@@ -76,13 +76,13 @@
   config.mutable_user_attributes_schema = {
     name: {
       givenName: :first_name,
-      familyName: :last_name
+      familyName: :last_name,
     },
     emails: [
       {
-        value: :email
+        value: :email,
       }
-    ]
+    ],
   }
 
   # Hash of SCIM structure for a user schema. This object
@@ -93,31 +93,31 @@
   # through as is, symbols will be passed to the user
   # object to return a value.
   config.user_schema = {
-    schemas: ["urn:ietf:params:scim:schemas:core:2.0:User"],
+    schemas: ['urn:ietf:params:scim:schemas:core:2.0:User'],
     id: :id,
     userName: :email,
     name: {
       givenName: :first_name,
-      familyName: :last_name
+      familyName: :last_name,
     },
     emails: [
       {
-        value: :email
+        value: :email,
       }
     ],
-    active: :active?
+    active: :active?,
   }
 
   # Schema for users used in "abbreviated" lists such as in
   # the `members` field of a Group.
   config.user_abbreviated_schema = {
     value: :id,
-    display: :email
+    display: :email,
   }
 
   # Allow filtering Groups based on these parameters
   config.queryable_group_attributes = {
-    displayName: :name
+    displayName: :name,
   }
 
   # List of attributes on a Group that can be updated through SCIM
@@ -131,7 +131,7 @@
   # include all attributes listed in
   # config.mutable_group_attributes.
   config.mutable_group_attributes_schema = {
-    displayName: :name
+    displayName: :name,
   }
 
   # The User relation's IDs field name on the Group model.
@@ -143,15 +143,15 @@
   config.group_member_relation_schema = { value: :user_ids }
 
   config.group_schema = {
-    schemas: ["urn:ietf:params:scim:schemas:core:2.0:Group"],
+    schemas: ['urn:ietf:params:scim:schemas:core:2.0:Group'],
     id: :id,
     displayName: :name,
-    members: :users
+    members: :users,
   }
 
   config.group_abbreviated_schema = {
     value: :id,
-    display: :name
+    display: :name,
   }
 
   # Set group_destroy_method to a method on the Group model
diff --git a/lib/scim_rails.rb b/lib/scim_rails.rb
index e12b30b3..a8f0835b 100644
--- a/lib/scim_rails.rb
+++ b/lib/scim_rails.rb
@@ -1,6 +1,6 @@
-require "scim_rails/engine"
-require "scim_rails/config"
-require "scim_rails/encoder"
+require 'scim_rails/engine'
+require 'scim_rails/config'
+require 'scim_rails/encoder'
 
 module ScimRails
 end
diff --git a/lib/scim_rails/encoder.rb b/lib/scim_rails/encoder.rb
index b5a264fd..4b4a8ef6 100644
--- a/lib/scim_rails/encoder.rb
+++ b/lib/scim_rails/encoder.rb
@@ -1,4 +1,4 @@
-require "jwt"
+require 'jwt'
 
 module ScimRails
   module Encoder
@@ -8,16 +8,18 @@ def encode(company)
       payload = {
         iat: Time.current.to_i,
         ScimRails.config.basic_auth_model_searchable_attribute =>
-          company.public_send(ScimRails.config.basic_auth_model_searchable_attribute)
+          company.public_send(ScimRails.config.basic_auth_model_searchable_attribute),
       }
 
-      JWT.encode(payload, ScimRails.config.signing_secret, ScimRails.config.signing_algorithm)
+      JWT.encode(payload, ScimRails.config.signing_secret,
+                 ScimRails.config.signing_algorithm)
     end
 
     def decode(token)
       verify = ScimRails.config.signing_algorithm != ScimRails::Config::ALGO_NONE
 
-      JWT.decode(token, ScimRails.config.signing_secret, verify, algorithm: ScimRails.config.signing_algorithm).first
+      JWT.decode(token, ScimRails.config.signing_secret, verify,
+                 algorithm: ScimRails.config.signing_algorithm).first
     rescue JWT::VerificationError, JWT::DecodeError
       raise ScimRails::ExceptionHandler::InvalidCredentials
     end
diff --git a/lib/scim_rails/engine.rb b/lib/scim_rails/engine.rb
index 6ed3f6ae..44ef8325 100644
--- a/lib/scim_rails/engine.rb
+++ b/lib/scim_rails/engine.rb
@@ -3,8 +3,8 @@ class Engine < ::Rails::Engine
     isolate_namespace ScimRails
 
     config.generators do |g|
-      g.test_framework :rspec, :fixture => false
-      g.fixture_replacement :factory_bot, :dir => "spec/factories"
+      g.test_framework :rspec, fixture: false
+      g.fixture_replacement :factory_bot, dir: 'spec/factories'
       g.assets false
       g.helper false
     end
diff --git a/scimaenaga.gemspec b/scimaenaga.gemspec
index 9279c89a..2664a99d 100644
--- a/scimaenaga.gemspec
+++ b/scimaenaga.gemspec
@@ -1,29 +1,32 @@
-$:.push File.expand_path("../lib", __FILE__)
+$:.push File.expand_path('lib', __dir__)
 
 # Maintain your gem's version:
-require "scim_rails/version"
+require 'scim_rails/version'
 
 # Describe your gem and declare its dependencies:
 Gem::Specification.new do |s|
-  s.name = "scimaenaga"
+  s.name = 'scimaenaga'
   s.version = ScimRails::VERSION
   s.authors = ['Studist Corporation']
-  s.homepage = "https://github.com/StudistCorporation/scimaenaga"
-  s.summary = "SCIM Adapter for Rails."
-  s.description = "SCIM Adapter for Rails."
-  s.license = "MIT"
+  s.homepage = 'https://github.com/StudistCorporation/scimaenaga'
+  s.summary = 'SCIM Adapter for Rails.'
+  s.description = 'SCIM Adapter for Rails.'
+  s.license = 'MIT'
 
-  s.files = Dir["{app,config,db,lib}/**/*", "MIT-LICENSE", "Rakefile", "README.md"]
+  s.files = Dir['{app,config,db,lib}/**/*', 'MIT-LICENSE', 'Rakefile', 'README.md']
 
-  s.required_ruby_version = ">= 2.5.9", "< 3.1"
-  s.add_dependency "rails", ">= 5.2.4.6", "< 6.2"
-  s.add_runtime_dependency "jwt", ">= 1.5"
-  s.test_files = Dir["spec/**/*"]
+  s.required_ruby_version = '>= 2.5.9', '< 3.1'
+  s.add_dependency 'rails', '>= 5.2.4.6', '< 6.2'
+  s.add_runtime_dependency 'jwt', '>= 1.5'
+  s.test_files = Dir['spec/**/*']
 
-  s.add_development_dependency "bundler", "~> 2.0"
-  s.add_development_dependency "factory_bot_rails"
-  s.add_development_dependency "pry"
-  s.add_development_dependency "rake", "~> 13.0"
-  s.add_development_dependency "rspec-rails", "~> 5.0"
-  s.add_development_dependency "sqlite3", "~> 1.3", "< 1.5"
+  s.add_development_dependency 'bundler', '~> 2.0'
+  s.add_development_dependency 'factory_bot_rails'
+  s.add_development_dependency 'pry'
+  s.add_development_dependency 'rake', '~> 13.0'
+  s.add_development_dependency 'rspec-rails', '~> 5.0'
+  s.add_development_dependency 'sqlite3', '~> 1.3', '< 1.5'
+  s.metadata = {
+    'rubygems_mfa_required' => 'true',
+  }
 end
diff --git a/spec/controllers/scim_rails/scim_groups_controller_spec.rb b/spec/controllers/scim_rails/scim_groups_controller_spec.rb
index f11ec456..72d1dd5d 100644
--- a/spec/controllers/scim_rails/scim_groups_controller_spec.rb
+++ b/spec/controllers/scim_rails/scim_groups_controller_spec.rb
@@ -417,8 +417,8 @@
             Operations: [{
               op: 'Replace',
               path: 'displayName',
-              value: 'changed'
-            }]
+              value: 'changed',
+            }],
           }, as: :json
         end.to change { group.reload.name }.to('changed')
 
@@ -572,7 +572,7 @@
       context 'whenr target Group is not found' do
         it 'return 404 not found' do
           expect do
-            delete :destroy, params: { id: 999999 }, as: :json
+            delete :destroy, params: { id: 999_999 }, as: :json
           end.not_to change { company.groups.reload.count }.from(1)
 
           expect(response.status).to eq 404
diff --git a/spec/controllers/scim_rails/scim_groups_request_spec.rb b/spec/controllers/scim_rails/scim_groups_request_spec.rb
index be40bee1..6d9c58d1 100644
--- a/spec/controllers/scim_rails/scim_groups_request_spec.rb
+++ b/spec/controllers/scim_rails/scim_groups_request_spec.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "spec_helper"
+require 'spec_helper'
 
 RSpec.describe ScimRails::ScimGroupsController, type: :request do
   let(:company) { create(:company) }
@@ -9,34 +9,34 @@
   end
   let(:authorization) { "Basic #{credentials}" }
 
-  def post_request(content_type = "application/scim+json")
-    post "/scim/v2/Groups",
+  def post_request(content_type = 'application/scim+json')
+    post '/scim/v2/Groups',
          params: {
-           displayName: "Dummy Group",
-           members: []
+           displayName: 'Dummy Group',
+           members: [],
          }.to_json,
          headers: {
            Authorization: authorization,
-           'Content-Type': content_type
+           'Content-Type': content_type,
          }
   end
 
-  describe "Content-Type" do
-    it "accepts scim+json" do
+  describe 'Content-Type' do
+    it 'accepts scim+json' do
       expect(company.groups.count).to eq 0
 
-      post_request("application/scim+json")
+      post_request('application/scim+json')
 
       expect(request.params).to include :displayName
       expect(response.status).to eq 201
-      expect(response.media_type).to eq "application/scim+json"
+      expect(response.media_type).to eq 'application/scim+json'
       expect(company.groups.count).to eq 1
     end
 
-    it "can not parse unfamiliar content types" do
+    it 'can not parse unfamiliar content types' do
       expect(company.groups.count).to eq 0
 
-      post_request("text/csv")
+      post_request('text/csv')
 
       expect(request.params).not_to include :displayName
       expect(response.status).to eq 422
@@ -44,21 +44,21 @@ def post_request(content_type = "application/scim+json")
     end
   end
 
-  context "OAuth Bearer Authorization" do
-    context "with valid token" do
+  context 'OAuth Bearer Authorization' do
+    context 'with valid token' do
       let(:authorization) { "Bearer #{company.api_token}" }
 
-      it "supports OAuth bearer authorization and succeeds" do
+      it 'supports OAuth bearer authorization and succeeds' do
         expect { post_request }.to change(company.groups, :count).from(0).to(1)
 
         expect(response.status).to eq 201
       end
     end
 
-    context "with invalid token" do
+    context 'with invalid token' do
       let(:authorization) { "Bearer #{SecureRandom.hex}" }
 
-      it "The request fails" do
+      it 'The request fails' do
         expect { post_request }.not_to change(company.groups, :count)
 
         expect(response.status).to eq 401
diff --git a/spec/controllers/scim_rails/scim_users_controller_spec.rb b/spec/controllers/scim_rails/scim_users_controller_spec.rb
index 96235c61..b7af6a4a 100644
--- a/spec/controllers/scim_rails/scim_users_controller_spec.rb
+++ b/spec/controllers/scim_rails/scim_users_controller_spec.rb
@@ -755,23 +755,23 @@
   describe 'destroy' do
     let(:company) { create(:company) }
 
-    context "when unauthorized" do
-      it "returns scim+json content type" do
+    context 'when unauthorized' do
+      it 'returns scim+json content type' do
         delete :destroy, params: { id: 1 }, as: :json
 
-        expect(response.media_type).to eq "application/scim+json"
+        expect(response.media_type).to eq 'application/scim+json'
       end
 
-      it "fails with no credentials" do
+      it 'fails with no credentials' do
         delete :destroy, params: { id: 1 }, as: :json
 
         expect(response.status).to eq 401
       end
 
-      it "fails with invalid credentials" do
-        request.env["HTTP_AUTHORIZATION"] =
+      it 'fails with invalid credentials' do
+        request.env['HTTP_AUTHORIZATION'] =
           ActionController::HttpAuthentication::Basic
-          .encode_credentials("unauthorized", "123456")
+          .encode_credentials('unauthorized', '123456')
 
         delete :destroy, params: { id: 1 }, as: :json
 
@@ -787,7 +787,6 @@
       end
 
       context 'when User destroy method is configured' do
-
         it 'is sucessful with valid credentials' do
           delete :destroy, params: { id: 1 }, as: :json
 
@@ -840,7 +839,7 @@
       context 'when target User is not found' do
         it 'return 404 not found' do
           expect do
-            delete :destroy, params: { id: 999999 }, as: :json
+            delete :destroy, params: { id: 999_999 }, as: :json
           end.not_to change { company.users.reload.count }.from(1)
 
           expect(response.status).to eq 404
diff --git a/spec/controllers/scim_rails/scim_users_request_spec.rb b/spec/controllers/scim_rails/scim_users_request_spec.rb
index 41a75c2e..7757866c 100644
--- a/spec/controllers/scim_rails/scim_users_request_spec.rb
+++ b/spec/controllers/scim_rails/scim_users_request_spec.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "spec_helper"
+require 'spec_helper'
 
 RSpec.describe ScimRails::ScimUsersController, type: :request do
   let(:company) { create(:company) }
@@ -9,43 +9,43 @@
   end
   let(:authorization) { "Basic #{credentials}" }
 
-  def post_request(content_type = "application/scim+json")
+  def post_request(content_type = 'application/scim+json')
     # params need to be transformed into a string to test if they are being parsed by Rack
 
-    post "/scim/v2/Users",
+    post '/scim/v2/Users',
          params: {
            name: {
-             givenName: "New",
-             familyName: "User"
+             givenName: 'New',
+             familyName: 'User',
            },
            emails: [
              {
-               value: "new@example.com"
+               value: 'new@example.com',
              }
-           ]
+           ],
          }.to_json,
          headers: {
            Authorization: authorization,
-           'Content-Type': content_type
+           'Content-Type': content_type,
          }
   end
 
-  describe "Content-Type" do
-    it "accepts scim+json" do
+  describe 'Content-Type' do
+    it 'accepts scim+json' do
       expect(company.users.count).to eq 0
 
-      post_request("application/scim+json")
+      post_request('application/scim+json')
 
       expect(request.params).to include :name
       expect(response.status).to eq 201
-      expect(response.media_type).to eq "application/scim+json"
+      expect(response.media_type).to eq 'application/scim+json'
       expect(company.users.count).to eq 1
     end
 
-    it "can not parse unfamiliar content types" do
+    it 'can not parse unfamiliar content types' do
       expect(company.users.count).to eq 0
 
-      post_request("text/csv")
+      post_request('text/csv')
 
       expect(request.params).not_to include :name
       expect(response.status).to eq 422
@@ -53,21 +53,21 @@ def post_request(content_type = "application/scim+json")
     end
   end
 
-  context "OAuth Bearer Authorization" do
-    context "with valid token" do
+  context 'OAuth Bearer Authorization' do
+    context 'with valid token' do
       let(:authorization) { "Bearer #{company.api_token}" }
 
-      it "supports OAuth bearer authorization and succeeds" do
+      it 'supports OAuth bearer authorization and succeeds' do
         expect { post_request }.to change(company.users, :count).from(0).to(1)
 
         expect(response.status).to eq 201
       end
     end
 
-    context "with invalid token" do
+    context 'with invalid token' do
       let(:authorization) { "Bearer #{SecureRandom.hex}" }
 
-      it "The request fails" do
+      it 'The request fails' do
         expect { post_request }.not_to change(company.users, :count)
 
         expect(response.status).to eq 401
diff --git a/spec/dummy/config/application.rb b/spec/dummy/config/application.rb
index 5a768aa3..ab87e5bb 100644
--- a/spec/dummy/config/application.rb
+++ b/spec/dummy/config/application.rb
@@ -3,7 +3,7 @@
 require 'rails/all'
 
 Bundler.require(*Rails.groups)
-require "scim_rails"
+require 'scim_rails'
 
 module Dummy
   class Application < Rails::Application
@@ -12,4 +12,3 @@ class Application < Rails::Application
     # -- all .rb files in that directory are automatically loaded.
   end
 end
-
diff --git a/spec/dummy/config/routes.rb b/spec/dummy/config/routes.rb
index cfcdb756..71a1c171 100644
--- a/spec/dummy/config/routes.rb
+++ b/spec/dummy/config/routes.rb
@@ -1,3 +1,3 @@
 Rails.application.routes.draw do
-  mount ScimRails::Engine => "/"
+  mount ScimRails::Engine => '/'
 end
diff --git a/spec/factories/company.rb b/spec/factories/company.rb
index 0097c4c7..1d778596 100644
--- a/spec/factories/company.rb
+++ b/spec/factories/company.rb
@@ -1,7 +1,7 @@
 FactoryBot.define do
   factory :company do
-    name { "Test Company" }
-    subdomain { "test" }
+    name { 'Test Company' }
+    subdomain { 'test' }
 
     after(:build) do |company|
       company.api_token = ScimRails::Encoder.encode(company)
diff --git a/spec/lib/scim_rails/encoder_spec.rb b/spec/lib/scim_rails/encoder_spec.rb
index 3a2b3fbb..fd1046ae 100644
--- a/spec/lib/scim_rails/encoder_spec.rb
+++ b/spec/lib/scim_rails/encoder_spec.rb
@@ -1,61 +1,63 @@
-require "spec_helper"
+require 'spec_helper'
 
 describe ScimRails::Encoder do
-  let(:company) { Company.new(subdomain: "test") }
+  let(:company) { Company.new(subdomain: 'test') }
 
-  describe "::encode" do
-    context "with signing configuration" do
-      it "generates a signed token with the company attribute" do
+  describe '::encode' do
+    context 'with signing configuration' do
+      it 'generates a signed token with the company attribute' do
         token   = ScimRails::Encoder.encode(company)
         payload = ScimRails::Encoder.decode(token)
 
-        expect(token).to match /[a-z|A-Z|0-9.]{16,}\.[a-z|A-Z|0-9.]{16,}/
-        expect(payload).to contain_exactly(["iat", Integer], ["subdomain", "test"])
+        expect(token).to match(/[a-z|A-Z0-9.]{16,}\.[a-z|A-Z0-9.]{16,}/)
+        expect(payload).to contain_exactly(['iat', Integer], %w[subdomain test])
       end
     end
 
-    context "without signing configuration" do
+    context 'without signing configuration' do
       before do
         allow(ScimRails.config).to receive(:signing_secret).and_return(nil)
         allow(ScimRails.config).to receive(:signing_algorithm).and_return(ScimRails::Config::ALGO_NONE)
       end
 
-      it "generates an unsigned token with the company attribute" do
+      it 'generates an unsigned token with the company attribute' do
         token   = ScimRails::Encoder.encode(company)
         payload = ScimRails::Encoder.decode(token)
 
-        expect(token).to match /[a-z|A-Z|0-9.]{16,}/
-        expect(payload).to contain_exactly(["iat", Integer], ["subdomain", "test"])
+        expect(token).to match(/[a-z|A-Z0-9.]{16,}/)
+        expect(payload).to contain_exactly(['iat', Integer], %w[subdomain test])
       end
     end
   end
 
-  describe "::decode" do
+  describe '::decode' do
     let(:token) { ScimRails::Encoder.encode(company) }
 
-    it "raises InvalidCredentials error for an invalid token" do
-      token = "f487bf84bfub4f74fj4894fnh483f4h4u8f"
-      expect { ScimRails::Encoder.decode(token) }.to raise_error ScimRails::ExceptionHandler::InvalidCredentials
+    it 'raises InvalidCredentials error for an invalid token' do
+      token = 'f487bf84bfub4f74fj4894fnh483f4h4u8f'
+      expect do
+        ScimRails::Encoder.decode(token)
+      end.to raise_error ScimRails::ExceptionHandler::InvalidCredentials
     end
 
-    context "with signing configuration" do
-      it "decodes a signed token, returning the company attributes" do
+    context 'with signing configuration' do
+      it 'decodes a signed token, returning the company attributes' do
         payload = ScimRails::Encoder.decode(token)
 
-        expect(payload).to contain_exactly(["iat", Integer], ["subdomain", "test"])
+        expect(payload).to contain_exactly(['iat', Integer], %w[subdomain test])
       end
     end
 
-    context "without signing configuration" do
+    context 'without signing configuration' do
       before do
         allow(ScimRails.config).to receive(:signing_secret).and_return(nil)
         allow(ScimRails.config).to receive(:signing_algorithm).and_return(ScimRails::Config::ALGO_NONE)
       end
 
-      it "decodes an unsigned token, returning the company attributes" do
+      it 'decodes an unsigned token, returning the company attributes' do
         payload = ScimRails::Encoder.decode(token)
 
-        expect(payload).to contain_exactly(["iat", Integer], ["subdomain", "test"])
+        expect(payload).to contain_exactly(['iat', Integer], %w[subdomain test])
       end
     end
   end
diff --git a/spec/models/scim_query_parser_spec.rb b/spec/models/scim_query_parser_spec.rb
index 5fe3ca0c..8a62d39f 100644
--- a/spec/models/scim_query_parser_spec.rb
+++ b/spec/models/scim_query_parser_spec.rb
@@ -3,18 +3,17 @@
 require 'spec_helper'
 
 describe ScimRails::ScimQueryParser do
-
   let(:query_string) { 'userName eq "taro"' }
-  let(:queryable_attributes) {
+  let(:queryable_attributes) do
     {
       userName: :name,
       emails: [
         {
-          value: :email
+          value: :email,
         }
-      ]
+      ],
     }
-  }
+  end
   let(:parser) { described_class.new(query_string, queryable_attributes) }
 
   describe '#attribute' do