6 files changed, 92 insertions, 0 deletions
diff --git a/lib/generators/rails/USAGE b/lib/generators/rails/USAGE
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+++ b/lib/generators/rails/USAGE
@@ -0,0 +1,12 @@
+Description:
+============
+    Stubs out a new mailbox class in app/mailboxes and invokes your template
+    engine and test framework generators.
+
+Example:
+========
+    rails generate mailbox inbox
+
+    creates a InboxMailbox class and test:
+        Mailbox:  app/mailboxes/inbox_mailbox.rb
+        Test:     test/mailboxes/inbox_mailbox_test.rb
diff --git a/lib/generators/rails/mailbox_generator.rb b/lib/generators/rails/mailbox_generator.rb
new file mode 100644
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+++ b/lib/generators/rails/mailbox_generator.rb
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+# frozen_string_literal: true
+
+module Rails
+  module Generators
+    class MailboxGenerator < NamedBase
+      source_root File.expand_path("templates", __dir__)
+
+      argument :actions, type: :array, default: [:process], banner: "method method"
+
+      check_class_collision suffix: "Mailbox"
+
+      def create_mailbox_file
+        template "mailbox.rb", File.join("app/mailboxes", class_path, "#{file_name}_mailbox.rb")
+
+        in_root do
+          if behavior == :invoke && !File.exist?(application_mailbox_file_name)
+            template "application_mailbox.rb", application_mailbox_file_name
+          end
+        end
+      end
+
+      hook_for :test_framework
+
+      private
+        def file_name # :doc:
+          @_file_name ||= super.sub(/_mailbox\z/i, "")
+        end
+
+        def application_mailbox_file_name
+          "app/mailboxes/application_mailbox.rb"
+        end
+    end
+  end
+end
diff --git a/lib/generators/rails/templates/application_mailbox.rb.tt b/lib/generators/rails/templates/application_mailbox.rb.tt
new file mode 100644
index 0000000000..be51eb3639
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+++ b/lib/generators/rails/templates/application_mailbox.rb.tt
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+# frozen_string_literal: true
+
+class ApplicationMailbox < ActionMailbox::Base
+  # routing /something/i => :somewhere
+end
diff --git a/lib/generators/rails/templates/mailbox.rb.tt b/lib/generators/rails/templates/mailbox.rb.tt
new file mode 100644
index 0000000000..9788bd9bb4
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+++ b/lib/generators/rails/templates/mailbox.rb.tt
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+# frozen_string_literal: true
+
+class <%= class_name %>Mailbox < ApplicationMailbox
+<% actions.each do |action| -%>
+  def <%= action %>
+  end
+<% end -%>
+end
diff --git a/lib/generators/test_unit/mailbox_generator.rb b/lib/generators/test_unit/mailbox_generator.rb
new file mode 100644
index 0000000000..2ec7d11a2f
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+++ b/lib/generators/test_unit/mailbox_generator.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module TestUnit
+  module Generators
+    class MailboxGenerator < ::Rails::Generators::NamedBase
+      source_root File.expand_path("templates", __dir__)
+
+      check_class_collision suffix: "MailboxTest"
+
+      def create_test_files
+        template "mailbox_test.rb", File.join("test/mailboxes", class_path, "#{file_name}_mailbox_test.rb")
+      end
+
+      private
+        def file_name # :doc:
+          @_file_name ||= super.sub(/_mailbox\z/i, "")
+        end
+    end
+  end
+end
diff --git a/lib/generators/test_unit/templates/mailbox_test.rb.tt b/lib/generators/test_unit/templates/mailbox_test.rb.tt
new file mode 100644
index 0000000000..41749808e3
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+++ b/lib/generators/test_unit/templates/mailbox_test.rb.tt
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class <%= class_name %>MailboxTest < ActionMailbox::TestCase
+  # test "receive mail" do
+  #   receive_inbound_email_from_mail \
+  #     to: '"someone" <someone@example.com>,
+  #     from: '"else" <else@example.com>',
+  #     subject: "Hello world!",
+  #     body: "Hello?"
+  # end
+end