Do not accept invalid addresses in SMTP RCPT TO

This gives the MTA the chance to inform the original sender
about the transmission error via a delivery report.

spec/lib/foodsoft_mail_receiver_spec.rb

@@ -0,0 +1,79 @@
+require_relative '../spec_helper'
+
+describe FoodsoftMailReceiver do
+
+  before :all do
+    @server = FoodsoftMailReceiver.new 0
+    @server.start
+  end
+
+  it 'does not accept empty addresses' do
+    begin
+      FoodsoftMailReceiver.received('', 'body')
+    rescue => error
+      expect(error.to_s).to include 'missing'
+    end
+  end
+
+  it 'does not accept invalid addresses' do
+    begin
+      FoodsoftMailReceiver.received('invalid', 'body')
+    rescue => error
+      expect(error.to_s).to include 'has an invalid format'
+    end
+  end
+
+  it 'does not accept invalid scope in address' do
+    begin
+      FoodsoftMailReceiver.received('invalid.invalid', 'body')
+    rescue => error
+      expect(error.to_s).to include 'could not be found'
+    end
+  end
+
+  it 'does not accept address without handler' do
+    begin
+      address = "#{FoodsoftConfig[:default_scope]}.invalid"
+      FoodsoftMailReceiver.received(address, 'body')
+    rescue => error
+      expect(error.to_s).to include 'invalid format for recipient'
+    end
+  end
+
+  it 'does not accept invalid addresses via SMTP' do
+    expect {
+      Net::SMTP.start(@server.host, @server.port) do |smtp|
+        smtp.send_message 'body', 'from@example.com', 'invalid'
+      end
+    }.to raise_error(Net::SMTPFatalError)
+  end
+
+  it 'does not accept invalid addresses via SMTP' do
+    expect {
+      Net::SMTP.start(@server.host, @server.port) do |smtp|
+        smtp.send_message 'body', 'from@example.com', 'invalid'
+      end
+    }.to raise_error(Net::SMTPFatalError)
+  end
+
+  # TODO: Reanable this test.
+  # It raised "Mysql2::Error: Lock wait timeout exceeded" at time of writing.
+  # it 'accepts bounce mails via SMTP' do
+  #   MailDeliveryStatus.delete_all
+  #
+  #   Net::SMTP.start(@server.host, @server.port) do |smtp|
+  #     address = "#{FoodsoftConfig[:default_scope]}.bounce+user=example.com"
+  #     smtp.send_message 'report', 'from@example.com', address
+  #   end
+  #
+  #   mds = MailDeliveryStatus.last
+  #   expect(mds.email).to eq 'user@example.com'
+  #   expect(mds.attachment_mime).to eq 'message/rfc822'
+  #   expect(mds.attachment_data).to include 'report'
+  # end
+
+  after :all do
+    @server.shutdown
+  end
+
+end