Add ActionMailer support

.rubocop.yml

@@ -13,6 +13,9 @@ Naming/MethodParameterName:
 RSpec/MultipleExpectations:
   Max: 4
 
+RSpec/NestedGroups:
+  Max: 4
+
 Style/Documentation:
   Enabled: false
 

CHANGELOG.md

@@ -5,3 +5,8 @@
 ## [1.0.1] - 2022-06-20
 
 - Update packed files list
+
+
+## [1.1.0] - 2022-07-22
+
+- Add ActionMailer support

Gemfile

@@ -4,6 +4,8 @@ source 'https://rubygems.org'
 
 gemspec
 
+gem 'mail'
+gem 'net-smtp'
 gem 'rake', '~> 13.0'
 gem 'rspec', '~> 3.0'
 gem 'rspec-its'

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    mailtrap (1.0.1)
+    mailtrap (1.1.0)
 
 GEM
   remote: https://rubygems.org/
@@ -13,6 +13,10 @@ GEM
       rexml
     diff-lcs (1.5.0)
     hashdiff (1.0.1)
+    mail (2.7.1)
+      mini_mime (>= 0.1.1)
+    mini_mime (1.1.2)
+    net-smtp (0.1.0)
     parallel (1.22.1)
     parser (3.1.2.0)
       ast (~> 2.4.1)
@@ -62,7 +66,9 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  mail
   mailtrap!
+  net-smtp
   rake (~> 13.0)
   rspec (~> 3.0)
   rspec-its

README.md

@@ -87,6 +87,27 @@ client = Mailtrap::Sending::Client.new(api_key: 'your-api-key')
 client.send(mail)
 ```
 
+### ActionMailer
+
+This gem also adds ActionMailer delivery method. To configure it, add following to your ActionMailer configuration (in Rails projects located in `config/$ENVIRONMENT.rb`):
+```ruby
+config.action_mailer.delivery_method = :mailtrap
+config.action_mailer.mailtrap_settings = {
+  api_key: ENV.fetch('MAILTRAP_API_KEY')
+}
+```
+And continue to use ActionMailer as usual.
+
+To add `category` and `custom_variables`, add them to the mail generation:
+```ruby
+mail(
+  to: '[email protected]',
+  subject: 'You are awesome!',
+  category: 'Test category',
+  custom_variables: { test_variable: 'abc' }
+)
+```
+
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.

lib/mailtrap.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require_relative 'mailtrap/action_mailer' if defined? ActionMailer
 require_relative 'mailtrap/sending'
 require_relative 'mailtrap/version'
 

lib/mailtrap/action_mailer.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+require_relative 'action_mailer/delivery_method'
+require_relative 'action_mailer/railtie' if defined? Rails
+
+module Mailtrap
+  module ActionMailer; end
+end

lib/mailtrap/action_mailer/delivery_method.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+module Mailtrap
+  module ActionMailer
+    class DeliveryMethod
+      attr_accessor :settings
+
+      def initialize(settings)
+        self.settings = settings
+      end
+
+      def deliver!(message)
+        mail = Mailtrap::Sending::Convert.from_message(message)
+
+        client.send(mail)
+      end
+
+      private
+
+      def client
+        @client ||= Mailtrap::Sending::Client.new(**settings.slice(:api_key, :api_host, :api_port))
+      end
+    end
+  end
+end

lib/mailtrap/action_mailer/railtie.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module Mailtrap
+  module ActionMailer
+    class Railtie < Rails::Railtie
+      initializer 'mailtrap_action_mailer.add_delivery_method', before: 'action_mailer.set_configs' do
+        ActiveSupport.on_load(:action_mailer) do
+          ::ActionMailer::Base.add_delivery_method(:mailtrap, Mailtrap::ActionMailer::DeliveryMethod)
+        end
+      end
+    end
+  end
+end

lib/mailtrap/sending.rb

@@ -2,6 +2,7 @@
 
 require_relative 'sending/attachment'
 require_relative 'sending/client'
+require_relative 'sending/convert'
 require_relative 'sending/mail'
 
 module Mailtrap

lib/mailtrap/sending/convert.rb

@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+require 'base64'
+
+module Mailtrap
+  module Sending
+    module Convert
+      class << self
+        def from_message(message) # rubocop:disable Metrics/AbcSize, Metrics/MethodLength, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
+          Mailtrap::Sending::Mail.new(
+            from: prepare_address(message['from']&.address_list&.addresses&.first),
+            to: prepare_addresses(message['to']&.address_list&.addresses),
+            cc: prepare_addresses(message['cc']&.address_list&.addresses),
+            bcc: prepare_addresses(message['bcc']&.address_list&.addresses),
+            subject: message.subject,
+            text: prepare_text_part(message),
+            html: prepare_html_part(message),
+            headers: prepare_headers(message),
+            attachments: prepare_attachments(message.attachments),
+            category: message['category']&.unparsed_value,
+            custom_variables: message['custom_variables']&.unparsed_value
+          )
+        end
+
+        private
+
+        PROCESSED_HEADERS = %w[
+          from
+          to
+          cc
+          bcc
+          subject
+          category
+          customvariables
+          contenttype
+        ].freeze
+
+        def prepare_addresses(addresses)
+          Array(addresses).map { |address| prepare_address(address) }
+        end
+
+        def prepare_headers(message)
+          message
+            .header_fields
+            .reject { |header| PROCESSED_HEADERS.include?(header.name.downcase.delete('-')) }
+            .to_h { |header| [header.name, header.value] }
+            .compact
+        end
+
+        def prepare_address(address)
+          {
+            email: address.address,
+            name: address.display_name
+          }.compact
+        end
+
+        def prepare_attachments(attachments_list = [])
+          attachments_list.map do |attachment|
+            {
+              content: Base64.strict_encode64(attachment.body.decoded),
+              type: attachment.mime_type,
+              filename: attachment.filename,
+              disposition: attachment.header[:content_disposition]&.disposition_type,
+              content_id: attachment.header[:content_id]&.field&.content_id
+            }.compact
+          end
+        end
+
+        def prepare_html_part(message)
+          return message.body.decoded if message.mime_type == 'text/html'
+
+          message.html_part&.decoded
+        end
+
+        def prepare_text_part(message)
+          return message.body.decoded if message.mime_type == 'text/plain' || message.mime_type.nil?
+
+          message.text_part&.decoded
+        end
+      end
+    end
+  end
+end

lib/mailtrap/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Mailtrap
-  VERSION = '1.0.1'
+  VERSION = '1.1.0'
 end

spec/fixtures/files/attachments/file.txt

@@ -0,0 +1 @@
+This is a text file

spec/mailtrap/action_mailer/delivery_method_spec.rb

@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+require 'mailtrap/action_mailer'
+
+RSpec.describe Mailtrap::ActionMailer::DeliveryMethod, :vcr do
+  describe '#deliver!' do
+    subject(:deliver!) { described_class.new(settings).deliver!(message) }
+
+    let(:settings) { { api_key: 'correct-api-key' } }
+    let(:message) { Mail::Message.new(params) }
+    let(:params) do
+      {
+        from: 'Mailtrap Test <[email protected]>',
+        to: 'To 1 <[email protected]>, [email protected]',
+        cc: '[email protected], Cc 2 <[email protected]>',
+        bcc: '[email protected], [email protected]',
+        reply_to: '[email protected]',
+        subject: 'You are awesome!',
+        category: 'Module Test'
+      }
+    end
+    let(:expected_message_ids) do
+      %w[
+        858cbc46-09d5-11ed-91e0-0a58a9feac02
+        858cbc5c-09d5-11ed-91e0-0a58a9feac02
+        858cbc6d-09d5-11ed-91e0-0a58a9feac02
+        858cbc7e-09d5-11ed-91e0-0a58a9feac02
+        858cbc90-09d5-11ed-91e0-0a58a9feac02
+        858cbca1-09d5-11ed-91e0-0a58a9feac02
+      ]
+    end
+
+    before do
+      allow(::Mail::ContentTypeField).to receive(:generate_boundary).and_return('--==_mimepart_random_boundary')
+      message.text_part = 'Some text'
+      message.html_part = '<div>HTML part</div>'
+      message.headers('X-Special-Domain-Specific-Header': 'SecretValue')
+      message.headers('One-more-custom-header': 'CustomValue')
+      message.attachments['file.txt'] = File.read('spec/fixtures/files/attachments/file.txt')
+      message.attachments['file.txt'].content_id = '<[email protected]>'
+      message.attachments.inline['file.png'] = File.read('spec/fixtures/files/attachments/file.png')
+      message.attachments['file.png'].content_id = '<[email protected]>'
+    end
+
+    it 'converts the message and sends via API' do
+      expect(deliver!).to eq({ success: true, message_ids: expected_message_ids })
+    end
+  end
+end