DE-1714: Add rubocop gem

Gemfile

@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 # Specify your gem's dependencies in mailgun.gemspec
 gemspec
 
-gem 'mini_mime'
 gem 'json', '~> 2.1', platform: :mri_19
+gem 'mini_mime'

Rakefile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'bundler/gem_tasks'
 require 'rake'
 require 'rspec/core/rake_task'
@@ -9,21 +11,21 @@ end
 
 desc 'Run unit specs'
 RSpec::Core::RakeTask.new('spec:unit') do |t|
-  t.rspec_opts = %w(--colour --format documentation)
+  t.rspec_opts = %w[--colour --format documentation]
   t.pattern = 'spec/unit/*_spec.rb', 'spec/unit/*/*_spec.rb'
 end
 
 desc 'Run integration specs'
 # Before running integration tests, you need to specify
 # a valid API KEY in the spec/spec_helper.rb file.
 RSpec::Core::RakeTask.new('spec:integration') do |t|
-  t.rspec_opts = %w(--colour --format documentation)
+  t.rspec_opts = %w[--colour --format documentation]
   t.pattern = 'spec/integration/*_spec.rb'
 end
 
 desc 'Run all tests'
 RSpec::Core::RakeTask.new('spec:all') do |t|
-  t.rspec_opts = %w(--colour --format documentation)
+  t.rspec_opts = %w[--colour --format documentation]
   t.pattern = 'spec/**/*_spec.rb'
 end
 

lib/mailgun-ruby.rb

@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 require_relative 'mailgun'
 require_relative 'railgun' if defined?(Rails) && defined?(ActionMailer)

lib/mailgun.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # require ruby dependencies
 require 'json'
 require 'openssl'
@@ -16,7 +18,7 @@
 require 'mailgun/helpers/api_version_checker'
 
 # load zeitwerk
-Zeitwerk::Loader.for_gem.tap do |loader| # rubocop:disable Style/SymbolProc
+Zeitwerk::Loader.for_gem.tap do |loader|
   loader.ignore("#{__dir__}/mailgun-ruby.rb")
   loader.ignore("#{__dir__}/railgun.rb")
   loader.ignore("#{__dir__}/railgun")
@@ -41,7 +43,6 @@
 #
 # See the Github documentation for full examples.
 module Mailgun
-
   class << self
     attr_accessor :api_host,
                   :api_key,
@@ -56,7 +57,6 @@ def configure
       yield self
       true
     end
-    alias_method :config, :configure
+    alias config configure
   end
-
 end

lib/mailgun/address.rb

@@ -1,5 +1,6 @@
-module Mailgun
+# frozen_string_literal: true
 
+module Mailgun
   # Mailgun::Address is a simple interface to the Email Validation API.
   class Address
     def initialize(api_key = Mailgun.api_key, api_host = Mailgun.api_host)
@@ -10,12 +11,11 @@ def initialize(api_key = Mailgun.api_key, api_host = Mailgun.api_host)
     #
     # @param [String] address Email address to validate (max 512 chars.)
     def validate(address, mailbox_verification = false)
-      params = {address:  address}
+      params = { address: address }
       params[:mailbox_verification] = true if mailbox_verification
 
-      res = @client.get "address/validate", params
-      return res.to_h!
+      res = @client.get 'address/validate', params
+      res.to_h!
     end
   end
-
 end

lib/mailgun/chains.rb

@@ -1,8 +1,8 @@
-module Mailgun
+# frozen_string_literal: true
 
+module Mailgun
   # Public constants used throughout
   class Chains
-
     # maximum campaign ids per message
     MAX_CAMPAIGN_IDS = 3
 
@@ -11,6 +11,5 @@ class Chains
 
     # maximum recipients per message or batch
     MAX_RECIPIENTS = 1000
-
   end
 end

lib/mailgun/client.rb

@@ -1,32 +1,33 @@
+# frozen_string_literal: true
+
 module Mailgun
   # A Mailgun::Client object is used to communicate with the Mailgun API. It is a
   # wrapper around Faraday so you don't have to worry about the HTTP aspect
   # of communicating with our API.
   #
   # See the Github documentation for full examples.
   class Client
-    SUBACCOUNT_HEADER = 'X-Mailgun-On-Behalf-Of'.freeze
+    SUBACCOUNT_HEADER = 'X-Mailgun-On-Behalf-Of'
 
     def initialize(api_key = Mailgun.api_key,
                    api_host = Mailgun.api_host || 'api.mailgun.net',
-                   api_version = Mailgun.api_version  || 'v3',
+                   api_version = Mailgun.api_version || 'v3',
                    ssl = true,
-                   test_mode = !!Mailgun.test_mode,
+                   test_mode = !Mailgun.test_mode.nil?,
                    timeout = nil,
                    proxy_url = Mailgun.proxy_url)
-
       endpoint = endpoint_generator(api_host, api_version, ssl)
 
       request_options = {
         url: endpoint,
         proxy: proxy_url,
-        ssl: {verify: ssl},
+        ssl: { verify: ssl },
         headers: {
-                   'User-Agent' => "mailgun-sdk-ruby/#{Mailgun::VERSION}",
-                   'Accept' =>'*/*'
-                  }
+          'User-Agent' => "mailgun-sdk-ruby/#{Mailgun::VERSION}",
+          'Accept' => '*/*'
+        }
       }
-      request_options.merge!(request: {timeout: timeout}) if timeout
+      request_options.merge!(request: { timeout: timeout }) if timeout
 
       @http_client = build_http_client(api_key, request_options)
 
@@ -55,7 +56,7 @@ def set_api_key(api_key)
 
     # Add subaccount id to headers
     def set_subaccount(subaccount_id)
-      @http_client.headers = @http_client.headers.merge!({ SUBACCOUNT_HEADER => subaccount_id })
+      @http_client.headers.merge!({ SUBACCOUNT_HEADER => subaccount_id })
     end
 
     # Reset subaccount for primary usage
@@ -71,9 +72,7 @@ def test_mode?
     end
 
     # @return [String] client api version
-    def api_version
-      @api_version
-    end
+    attr_reader :api_version
 
     # Provides a store of all the emails sent in test mode so you can check them.
     #
@@ -91,12 +90,12 @@ def self.deliveries
     def send_message(working_domain, data)
       perform_data_validation(working_domain, data)
 
-      if test_mode? then
+      if test_mode?
         Mailgun::Client.deliveries << data.dup
         return Response.from_hash(
           {
-            :body => "{\"id\": \"test-mode-mail-#{SecureRandom.uuid}@localhost\", \"message\": \"Queued. Thank you.\"}",
-            :status => 200,
+            body: "{\"id\": \"test-mode-mail-#{SecureRandom.uuid}@localhost\", \"message\": \"Queued. Thank you.\"}",
+            status: 200
           }
         )
       end
@@ -106,7 +105,7 @@ def send_message(working_domain, data)
         # Remove nil values from the data hash
         # Submitting nils to the API will likely cause an error.
         #  See also: https://github.com/mailgun/mailgun-ruby/issues/32
-        data = data.select { |k, v| v != nil }
+        data = data.reject { |_k, v| v.nil? }
 
         if data.key?(:message)
           if data[:message].is_a?(String)
@@ -119,7 +118,7 @@ def send_message(working_domain, data)
       when MessageBuilder
         post("#{working_domain}/messages", data.message)
       else
-        fail ParameterError.new('Unknown data type for data parameter.', data)
+        raise ParameterError.new('Unknown data type for data parameter.', data)
       end
     end
 
@@ -134,8 +133,8 @@ def send_message(working_domain, data)
     def post(resource_path, data, headers = {})
       response = @http_client.post(resource_path, data, headers)
       Response.new(response)
-    rescue => err
-      raise communication_error err
+    rescue StandardError => e
+      raise communication_error e
     end
 
     # Generic Mailgun GET Handler
@@ -151,8 +150,8 @@ def get(resource_path, params = {}, accept = '*/*')
       response = @http_client.get(resource_path, params, headers)
 
       Response.new(response)
-    rescue => err
-      raise communication_error(err)
+    rescue StandardError => e
+      raise communication_error(e)
     end
 
     # Generic Mailgun PUT Handler
@@ -165,8 +164,8 @@ def get(resource_path, params = {}, accept = '*/*')
     def put(resource_path, data, headers = {})
       response = @http_client.put(resource_path, data, headers)
       Response.new(response)
-    rescue => err
-      raise communication_error err
+    rescue StandardError => e
+      raise communication_error e
     end
 
     # Generic Mailgun DELETE Handler
@@ -188,8 +187,8 @@ def delete(resource_path, params = nil, body_params = false)
           @http_client.delete(resource_path)
         end
       Response.new(response)
-    rescue => err
-      raise communication_error err
+    rescue StandardError => e
+      raise communication_error e
     end
 
     # Constructs a Suppressions client for the given domain.
@@ -221,7 +220,7 @@ def convert_string_to_file(string)
     # @param [Boolean] ssl True, SSL. False, No SSL.
     # @return [string] concatenated URL string
     def endpoint_generator(api_host, api_version, ssl)
-      ssl ? scheme = 'https' : scheme = 'http'
+      scheme = ssl ? 'https' : 'http'
       if api_version
         "#{scheme}://#{api_host}/#{api_version}"
       else
@@ -235,28 +234,33 @@ def endpoint_generator(api_host, api_version, ssl)
     def communication_error(e)
       if e.respond_to?(:response) && e.response
         return case e.response_status
-        when Unauthorized::CODE
-          Unauthorized.new(e.message, e.response)
-        when BadRequest::CODE
-          BadRequest.new(e.message, e.response)
-        else
-          CommunicationError.new(e.message, e.response)
-        end
+               when Unauthorized::CODE
+                 Unauthorized.new(e.message, e.response)
+               when BadRequest::CODE
+                 BadRequest.new(e.message, e.response)
+               else
+                 CommunicationError.new(e.message, e.response)
+               end
       end
       CommunicationError.new(e.message)
     end
 
     def perform_data_validation(working_domain, data)
       message = data.respond_to?(:message) ? data.message : data
-      fail ParameterError.new('Missing working domain', working_domain) unless working_domain
-      fail ParameterError.new(
-        'Missing `to` recipient, message should contain at least 1 recipient',
-        working_domain
-      ) if message.fetch('to', []).empty? && message.fetch(:to, []).empty?
-      fail ParameterError.new(
+      raise ParameterError.new('Missing working domain', working_domain) unless working_domain
+
+      if message.fetch('to', []).empty? && message.fetch(:to, []).empty?
+        raise ParameterError.new(
+          'Missing `to` recipient, message should contain at least 1 recipient',
+          working_domain
+        )
+      end
+      return unless message.fetch('from', []).empty? && message.fetch(:from, []).empty?
+
+      raise ParameterError.new(
         'Missing a `from` sender, message should contain at least 1 `from` sender',
         working_domain
-      ) if message.fetch('from', []).empty? && message.fetch(:from, []).empty?
+      )
     end
 
     def build_http_client(api_key, request_options)