Add RuboCop linting and use frozen_string_literal everywhere

.rubocop.yml

@@ -0,0 +1,5 @@
+Layout/LineLength:
+  Max: 120
+
+Style/StringLiterals:
+  EnforcedStyle: double_quotes

hubspot-mailer.gemspec

@@ -1,38 +1,40 @@
+# frozen_string_literal: true
+
 Gem::Specification.new do |s|
-  s.name        = "hubspot-mailer".freeze
+  s.name        = "hubspot-mailer"
   s.version     = "0.0.2"
-  s.licenses    = ['MIT']
-  s.date        = "2018-12-09".freeze
-  s.description = "Create beautiful transactional emails right within HubSpot using the email editor with all the benefits of smart content, personalization and templates - just like regular HubSpot emails. Create beautiful transactional emails right within HubSpot using the email editor with all the benefits of smart content, personalization and templates - just like regular HubSpot emails. Create beautiful transactional emails right within HubSpot using the email editor with all the benefits of smart content, personalization and templates - just like regular HubSpot emails.".freeze
-  s.summary     = "HubSpot Single Send API SDK for use with Ruby on Rails".freeze
-  s.authors     = ["heaven".freeze]
-  s.email       = ["[email protected]".freeze]
-  s.homepage    = "https://github.com/heaven/hubspot-mailer".freeze
+  s.licenses    = ["MIT"]
+  s.date        = "2018-12-09"
+  s.description = "Create beautiful transactional emails right within HubSpot using the email editor with all the benefits of smart content, personalization and templates - just like regular HubSpot emails. Create beautiful transactional emails right within HubSpot using the email editor with all the benefits of smart content, personalization and templates - just like regular HubSpot emails. Create beautiful transactional emails right within HubSpot using the email editor with all the benefits of smart content, personalization and templates - just like regular HubSpot emails."
+  s.summary     = "HubSpot Single Send API SDK for use with Ruby on Rails"
+  s.authors     = ["heaven"]
+  s.email       = ["[email protected]"]
+  s.homepage    = "https://github.com/heaven/hubspot-mailer"
   s.files       = [
     "lib/hubspot-mailer.rb",
     "lib/hubspot/mailer.rb",
     "lib/hubspot/mailer/delivery.rb",
     "lib/hubspot/mailer/exceptions.rb",
     "lib/hubspot/mailer/hubspot_preview_interceptor.rb",
-    "lib/hubspot/mailer/message.rb",
+    "lib/hubspot/mailer/message.rb"
   ]
   s.require_paths = ["lib"]
 
   if s.respond_to? :specification_version
     s.specification_version = 3
 
-    if Gem::Version.new(Gem::VERSION) >= Gem::Version.new('1.2.0')
-      s.add_runtime_dependency(%q<hubspot-ruby>.freeze, ["~> 0.4"])
-      s.add_runtime_dependency(%q<actionmailer>.freeze, ["~> 5.1"])
-      s.add_development_dependency(%q<bundler>.freeze, ["~> 1.0"])
+    if Gem::Version.new(Gem::VERSION) >= Gem::Version.new("1.2.0")
+      s.add_runtime_dependency("actionmailer", ["~> 5.1"])
+      s.add_runtime_dependency("hubspot-ruby", ["~> 0.4"])
+      s.add_development_dependency("bundler", ["~> 1.0"])
     else
-      s.add_dependency(%q<hubspot-ruby>.freeze, ["~> 0.4"])
-      s.add_dependency(%q<actionmailer>.freeze, ["~> 5.1"])
-      s.add_dependency(%q<bundler>.freeze, ["~> 1.0"])
+      s.add_dependency("actionmailer", ["~> 5.1"])
+      s.add_dependency("bundler", ["~> 1.0"])
+      s.add_dependency("hubspot-ruby", ["~> 0.4"])
     end
   else
-    s.add_dependency(%q<hubspot-ruby>.freeze, ["~> 0.4"])
-    s.add_dependency(%q<actionmailer>.freeze, ["~> 5.1"])
-    s.add_dependency(%q<bundler>.freeze, ["~> 1.0"])
+    s.add_dependency("actionmailer", ["~> 5.1"])
+    s.add_dependency("bundler", ["~> 1.0"])
+    s.add_dependency("hubspot-ruby", ["~> 0.4"])
   end
 end

lib/hubspot-mailer.rb

@@ -1,8 +1,9 @@
-require 'action_mailer'
-require 'hubspot-ruby'
-require 'hubspot/mailer/delivery'
-require 'hubspot/mailer/exceptions'
-require 'hubspot/mailer/hubspot_preview_interceptor'
-require 'hubspot/mailer/message'
-require 'hubspot/mailer'
+# frozen_string_literal: true
 
+require "action_mailer"
+require "hubspot-ruby"
+require "hubspot/mailer/delivery"
+require "hubspot/mailer/exceptions"
+require "hubspot/mailer/hubspot_preview_interceptor"
+require "hubspot/mailer/message"
+require "hubspot/mailer"

lib/hubspot/mailer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Hubspot
   class Mailer < ActionMailer::Base
     abstract!
@@ -15,7 +17,7 @@ class Mailer < ActionMailer::Base
 
     self.default_params = {}.freeze
 
-    SINGLE_SEND_PATH = '/email/public/v1/singleEmail/send'.freeze
+    SINGLE_SEND_PATH = "/email/public/v1/singleEmail/send"
 
     class << self
       # Wraps an email delivery inside of <tt>ActiveSupport::Notifications</tt> instrumentation.
@@ -82,19 +84,19 @@ def single_send_params(mail)
         end
 
         # Copy subject from header to custom property
-        if mail.subject.present? and not mail.custom_properties.try(:[], :subject)
+        if mail.subject.present? && !mail.custom_properties.try(:[], :subject)
           mail.custom_properties ||= {}
           mail.custom_properties[:subject] = mail.subject
         end
 
         if mail.contact_properties.present?
           data[:contactProperties] =
-            Hubspot::Utils.hash_to_properties(mail.contact_properties, :key_name => :name)
+            Hubspot::Utils.hash_to_properties(mail.contact_properties, key_name: :name)
         end
 
         if mail.custom_properties.present?
           data[:customProperties] =
-            Hubspot::Utils.hash_to_properties(mail.custom_properties, :key_name => :name)
+            Hubspot::Utils.hash_to_properties(mail.custom_properties, key_name: :name)
         end
 
         data
@@ -104,20 +106,21 @@ def parse_response(response)
         status_code = response["sendResult"]
 
         case status_code
-          when "SENT", "QUEUED"
-            response["eventId"]
-          when "INVALID_TO_ADDRESS"
-            raise RecipientAddressError.new(response), "The TO address is invalid: #{status_code}"
-          when "INVALID_FROM_ADDRESS"
-            raise SenderAddressError.new(response), "The FROM address is invalid: #{status_code}"
-          when "BLOCKED_DOMAIN", "PORTAL_SUSPENDED"
-            raise SendingError.new(response), "Message can't be sent: #{status_code}"
-          when "PREVIOUSLY_BOUNCED", "PREVIOUS_SPAM"
-            raise DeliveryError.new(response), "Message can't be delivered: #{status_code}"
-          when "MISSING_CONTENT"
-            raise InvalidTemplateError.new(response), "The emailId is invalid, or the emailId is an email that is not set up for Single Send: #{status_code}"
-          else
-            raise UnknownResponseError.new(response), "Unrecognized status code: #{status_code}"
+        when "SENT", "QUEUED"
+          response["eventId"]
+        when "INVALID_TO_ADDRESS"
+          raise RecipientAddressError.new(response), "The TO address is invalid: #{status_code}"
+        when "INVALID_FROM_ADDRESS"
+          raise SenderAddressError.new(response), "The FROM address is invalid: #{status_code}"
+        when "BLOCKED_DOMAIN", "PORTAL_SUSPENDED"
+          raise SendingError.new(response), "Message can't be sent: #{status_code}"
+        when "PREVIOUSLY_BOUNCED", "PREVIOUS_SPAM"
+          raise DeliveryError.new(response), "Message can't be delivered: #{status_code}"
+        when "MISSING_CONTENT"
+          raise InvalidTemplateError.new(response),
+                "The emailId is invalid, or the emailId is an email that is not set up for Single Send: #{status_code}"
+        else
+          raise UnknownResponseError.new(response), "Unrecognized status code: #{status_code}"
         end
       end
     end
@@ -173,7 +176,8 @@ def assign_attributes_to_message(message, headers)
 
     def assign_headers_to_message(message, headers)
       headers.except(:parts_order, :content_type, :body, :template_name,
-        :template_path, :delivery_method, :delivery_method_options).each { |k, v| message[k] = v }
+                     :template_path, :delivery_method, :delivery_method_options)
+             .each { |k, v| message[k] = v }
     end
   end
 end

lib/hubspot/mailer/delivery.rb

@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 module Hubspot
   class Mailer < ActionMailer::Base
     class Delivery
       attr_accessor :settings
 
-      DEFAULTS = {}
+      DEFAULTS = {}.freeze
 
       def initialize(values)
         self.settings = DEFAULTS.merge(values)

lib/hubspot/mailer/exceptions.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Hubspot
   class Mailer < ActionMailer::Base
     class MissingTemplateError < StandardError; end

lib/hubspot/mailer/hubspot_preview_interceptor.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Hubspot
   class Mailer < ActionMailer::Base
     class HubspotPreviewInterceptor
@@ -21,7 +23,8 @@ def transform!
 
       def build_preview
         if message.message.is_a?(Hubspot::Mailer::Message)
-          html_part = "<b>Email ID (template)</b>: #{message.email_id}<br/><br/>"
+          html_part = String.new
+          html_part << "<b>Email ID (template)</b>: #{message.email_id}<br/><br/>"
 
           html_part << list_properties("Contact Properties (use via {{contact.propertyname}})", message.contact_properties)
           html_part << list_properties("Custom Properties (use via {{custom.property_name}})", message.custom_properties)
@@ -33,7 +36,7 @@ def build_preview
       end
 
       def list_properties(label, list)
-        buffer = ""
+        buffer = String.new
         return buffer unless list.present?
 
         buffer << "<b>#{label}</b>:<ul>"

lib/hubspot/mailer/message.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Hubspot
   class Mailer < ActionMailer::Base
     class Message < Mail::Message