4 files changed, 89 insertions, 4 deletions

diff --git a/lib/action_mailroom/router.rb b/lib/action_mailroom/router.rb
index bf0001f1ae..c3fa183438 100644
--- a/lib/action_mailroom/router.rb
+++ b/lib/action_mailroom/router.rb
@@ -1,20 +1,34 @@
 class ActionMailroom::Router
+  class RoutingError < StandardError; end
+
   def initialize
-    @routes = {}
+    @routes = []
   end
 
   def add_routes(routes)
-    @routes.merge!(routes)
+    routes.each do |(address, mailbox_name)|
+      add_route address, to: mailbox_name
+    end
+  end
+
+  def add_route(address, to:)
+    routes.append Route.new(address, to: to)
   end
 
   def route(inbound_email)
-    locate_mailbox(inbound_email).receive(inbound_email)
+    if mailbox = locate_mailbox(inbound_email)
+      mailbox.receive(inbound_email)
+    else
+      raise RoutingError
+    end
   end
 
   private
     attr_reader :routes
 
     def locate_mailbox(inbound_email)
-      "#{routes[inbound_email.mail.to.first].to_s.capitalize}Mailbox".constantize
+      routes.detect { |route| route.match?(inbound_email) }.try(:mailbox_class)
     end
 end
+
+require "action_mailroom/router/route"
diff --git a/lib/action_mailroom/router/route.rb b/lib/action_mailroom/router/route.rb
new file mode 100644
index 0000000000..316c77d711
--- /dev/null
+++ b/lib/action_mailroom/router/route.rb
@@ -0,0 +1,26 @@
+class ActionMailroom::Router::Route
+  class InvalidAddressError < StandardError; end
+
+  attr_reader :address, :mailbox_name
+
+  def initialize(address, to:)
+    @address, @mailbox_name = address, to
+  end
+
+  def match?(inbound_email)
+    case address
+    when String
+      inbound_email.mail.to.include?(address)
+    when Regexp
+      inbound_email.mail.to.detect { |recipient| address.match?(recipient) }
+    when Proc
+      address.call(inbound_email)
+    else
+      address.try(:match?, inbound_email) || raise(InvalidAddressError)
+    end
+  end
+
+  def mailbox_class
+    "#{mailbox_name.to_s.capitalize}Mailbox".constantize
+  end
+end
diff --git a/lib/action_mailroom/test_helper.rb b/lib/action_mailroom/test_helper.rb
index fbfb2797d9..33d32ec899 100644
--- a/lib/action_mailroom/test_helper.rb
+++ b/lib/action_mailroom/test_helper.rb
@@ -1,3 +1,5 @@
+require "mail"
+
 module ActionMailroom
   module TestHelper
     # Create an InboundEmail record using an eml fixture in the format of message/rfc822
diff --git a/test/unit/router_test.rb b/test/unit/router_test.rb
index 8cc7bd8810..25a2651bb6 100644
--- a/test/unit/router_test.rb
+++ b/test/unit/router_test.rb
@@ -13,6 +13,12 @@ end
 class SecondMailbox < RootMailbox
 end
 
+class FirstMailboxAddress
+  def match?(inbound_email)
+    inbound_email.mail.to.include?("replies-class@example.com")
+  end
+end
+
 module ActionMailroom
   class RouterTest < ActiveSupport::TestCase
     setup do
@@ -42,5 +48,42 @@ module ActionMailroom
       assert_equal "SecondMailbox", $processed_by
       assert_equal inbound_email.mail, $processed_mail
     end
+    
+    test "single regexp route" do
+      @router.add_routes(/replies-\w+@example.com/ => :first, "replies-nowhere@example.com" => :second)
+
+      inbound_email = create_inbound_email_from_mail(to: "replies-okay@example.com", subject: "This is a reply")
+      @router.route inbound_email
+      assert_equal "FirstMailbox", $processed_by
+    end
+
+    test "single proc route" do
+      @router.add_route \
+        ->(inbound_email) { inbound_email.mail.to.include?("replies-proc@example.com") },
+        to: :second
+
+      @router.route create_inbound_email_from_mail(to: "replies-proc@example.com", subject: "This is a reply")
+      assert_equal "SecondMailbox", $processed_by
+    end
+
+    test "address class route" do
+      @router.add_route FirstMailboxAddress.new, to: :first
+      @router.route create_inbound_email_from_mail(to: "replies-class@example.com", subject: "This is a reply")
+      assert_equal "FirstMailbox", $processed_by
+    end
+
+    test "missing route" do
+      assert_raises(ActionMailroom::Router::RoutingError) do
+        inbound_email = create_inbound_email_from_mail(to: "going-nowhere@example.com", subject: "This is a reply")
+        @router.route inbound_email
+      end
+    end
+
+    test "invalid address" do
+      assert_raises(ActionMailroom::Router::Route::InvalidAddressError) do
+        @router.add_route Array.new, to: :first
+        @router.route create_inbound_email_from_mail(to: "replies-nowhere@example.com", subject: "This is a reply")
+      end
+    end
   end
 end