Add MailerSend email provider

README.md

@@ -196,6 +196,7 @@ Courrier supports these transactional email providers:
 - [Cloudflare Email Service](https://developers.cloudflare.com/email-service/)
 - [Lettermint](https://lettermint.co)
 - [Loops](https://loops.so)
+- [MailerSend](https://www.mailersend.com/)
 - [Mailgun](https://mailgun.com)
 - [MailPace](https://mailpace.com)
 - [Postmark](https://postmarkapp.com)

lib/courrier/email/provider.rb

@@ -6,6 +6,7 @@
 require "courrier/email/providers/lettermint"
 require "courrier/email/providers/logger"
 require "courrier/email/providers/loops"
+require "courrier/email/providers/mailersend"
 require "courrier/email/providers/mailgun"
 require "courrier/email/providers/mailjet"
 require "courrier/email/providers/mailpace"
@@ -26,6 +27,7 @@ class Provider
         logger: Courrier::Email::Providers::Logger,
         lettermint: Courrier::Email::Providers::Lettermint,
         loops: Courrier::Email::Providers::Loops,
+        mailersend: Courrier::Email::Providers::Mailersend,
         mailgun: Courrier::Email::Providers::Mailgun,
         mailjet: Courrier::Email::Providers::Mailjet,
         mailpace: Courrier::Email::Providers::Mailpace,

lib/courrier/email/providers/mailersend.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module Courrier
+  class Email
+    module Providers
+      class Mailersend < Base
+        ENDPOINT_URL = "https://api.mailersend.com/v1/email"
+
+        def body
+          {
+            "from" => email_address(@options.from),
+            "to" => email_addresses(@options.to),
+            "cc" => email_addresses(@options.cc),
+            "bcc" => email_addresses(@options.bcc),
+            "reply_to" => email_address(@options.reply_to),
+            "subject" => @options.subject,
+            "text" => @options.text,
+            "html" => @options.html
+          }.compact
+        end
+
+        private
+
+        def default_headers = {"Authorization" => "Bearer #{@api_key}"}
+
+        def email_addresses(addresses)
+          addresses&.split(",")&.map { |address| email_address(address) }
+        end
+
+        def email_address(address)
+          {"email" => address.strip} if address
+        end
+      end
+    end
+  end
+end

test/courrier/email/providers/mailersend_test.rb

@@ -0,0 +1,52 @@
+require "test_helper"
+
+module Courrier::Email::Providers
+  class MailersendTest < Minitest::Test
+    def setup
+      email = TestEmail.new(
+        from: "devs@railsdesigner.com",
+        to: "first@example.com, second@example.com",
+        reply_to: "support@railsdesigner.com",
+        cc: "copy@example.com",
+        bcc: "archive@example.com"
+      )
+
+      @provider = Mailersend.new(api_key: "test_key", options: email.options)
+    end
+
+    def test_formats_transactional_email
+      assert_equal(
+        {
+          "from" => {"email" => "devs@railsdesigner.com"},
+          "to" => [{"email" => "first@example.com"}, {"email" => "second@example.com"}],
+          "cc" => [{"email" => "copy@example.com"}],
+          "bcc" => [{"email" => "archive@example.com"}],
+          "reply_to" => {"email" => "support@railsdesigner.com"},
+          "subject" => "Test Subject",
+          "text" => "Test Body",
+          "html" => "<p>Test HTML Body</p>"
+        },
+        @provider.body
+      )
+    end
+
+    def test_authenticates_with_api_key
+      assert_equal({"Authorization" => "Bearer test_key"}, @provider.send(:default_headers))
+    end
+
+    def test_is_available_through_provider_registry
+      mock_provider = Minitest::Mock.new
+      mock_provider.expect(:deliver, nil)
+
+      Mailersend.stub :new, mock_provider do
+        Courrier::Email::Provider.new(
+          provider: "mailersend",
+          api_key: "test_key",
+          options: @provider.instance_variable_get(:@options)
+        ).deliver
+      end
+
+      mock_provider.verify
+    end
+  end
+end