dmails: factor out spam detector service.

app/controllers/dmails_controller.rb

@@ -58,13 +58,11 @@ class DmailsController < ApplicationController
   def spam
     @dmail = Dmail.find(params[:id])
     @dmail.update_column(:is_spam, true)
-    @dmail.spam!
   end
 
   def ham
     @dmail = Dmail.find(params[:id])
     @dmail.update_column(:is_spam, false)
-    @dmail.ham!
   end
 
 private

app/logical/spam_detector.rb

@@ -0,0 +1,44 @@
+# https://github.com/joshfrench/rakismet
+# https://akismet.com/development/api/#comment-check
+
+class SpamDetector
+  include Rakismet::Model
+
+  attr_accessor :user, :user_ip, :content, :comment_type
+  rakismet_attrs author: proc { user.name },
+                 author_email: proc { user.email },
+                 blog_lang: "en",
+                 blog_charset: "UTF-8",
+                 comment_type: :comment_type,
+                 content: :content,
+                 user_ip: :user_ip
+
+  def self.enabled?
+    Danbooru.config.rakismet_key.present? && Danbooru.config.rakismet_url.present? && !Rails.env.test?
+  end
+
+  # rakismet raises an exception if the api key or url aren't configured
+  def self.working?
+    Rakismet.validate_key
+  rescue
+    false
+  end
+
+  def initialize(record)
+    case record
+    when Dmail
+      @user = record.from
+      @content = record.body
+      @comment_type = "message"
+      @user_ip = record.creator_ip_addr.to_s
+    else
+      raise ArgumentError
+    end
+  end
+
+  def spam?
+    return false if !SpamDetector.enabled?
+    return false if user.is_gold?
+    super
+  end
+end

app/models/dmail.rb

@@ -6,8 +6,6 @@ class Dmail < ApplicationRecord
   AUTOBAN_WINDOW = 24.hours
   AUTOBAN_DURATION = 3
 
-  include Rakismet::Model
-
   validates_presence_of :title, :body, on: :create
   validate :validate_sender_is_not_banned, on: :create
   validate :user_not_limited, on: :create
@@ -21,8 +19,6 @@ class Dmail < ApplicationRecord
   after_create :update_recipient
   after_commit :send_email, on: :create
 
-  rakismet_attrs author: -> { from.name }, author_email: -> { from.email }, content: -> { title + "\n\n" + body }, user_ip: -> { creator_ip_addr.to_s }
-
   concerning :SpamMethods do
     class_methods do
       def is_spammer?(user)
@@ -42,9 +38,7 @@ class Dmail < ApplicationRecord
     end
 
     def spam?
-      return false if Danbooru.config.rakismet_key.blank?
-      return false if from.is_janitor?
-      super()
+      SpamDetector.new(self).spam?
     end
   end
 
@@ -253,7 +247,7 @@ class Dmail < ApplicationRecord
       to.update(has_mail: true, unread_dmail_count: to.dmails.unread.count)
     end
   end
-  
+
   def visible_to?(user)
     owner_id == user.id || (user.is_admin? && (to.is_admin? || from.is_admin? || Ticket.exists?(qtype: 'dmail', disp_id: id)))
   end

config/danbooru_default_config.rb

@@ -845,6 +845,7 @@ module Danbooru
     end
 
     def rakismet_url
+      "https://#{hostname}"
     end
 
     # Cloudflare data

test/unit/dmail_test.rb

@@ -18,7 +18,8 @@ class DmailTest < ActiveSupport::TestCase
     context "spam" do
       setup do
         Dmail.any_instance.stubs(:spam?).returns(true)
-        @recipient = FactoryBot.create(:user)
+        @spammer = create(:user)
+        @recipient = create(:user)
       end
 
       should "not validate" do

test/unit/spam_detector.rb

@@ -0,0 +1,31 @@
+require "test_helper"
+
+class SpamDetectorTest < ActiveSupport::TestCase
+  context "SpamDetector" do
+    setup do
+      skip "SpamDetector not working: API key not configured, not valid, or akismet is down" if !SpamDetector.working?
+      SpamDetector.stubs(:enabled?).returns(true)
+
+      @user = create(:gold_user)
+      @spammer = create(:user, email: "akismet-guaranteed-spam@example.com")
+    end
+
+    context "for dmails" do
+      should "detect spam" do
+        Dmail.create_split(from: @spammer, to: @user, title: "spam", body: "wonderful spam", creator_ip_addr: "127.0.0.1")
+
+        dmail = @user.dmails.last
+        assert(SpamDetector.new(dmail).spam?)
+        assert(dmail.is_spam?)
+      end
+
+      should "not detect gold users as spammers" do
+        Dmail.create_split(from: @user, to: @spammer, title: "spam", body: "wonderful spam", creator_ip_addr: "127.0.0.1")
+
+        dmail = @spammer.dmails.last
+        refute(SpamDetector.new(dmail).spam?)
+        refute(dmail.is_spam?)
+      end
+    end
+  end
+end