FEATURE: limit daily emails per user to 100 per day via site setting

- controlled via max_emails_per_day_per_user, 0 to disable
- when limit is reached user is warned

spec/jobs/notify_mailing_list_subscribers_spec.rb

@@ -3,9 +3,34 @@ require "rails_helper"
 describe Jobs::NotifyMailingListSubscribers do
 
   context "with mailing list on" do
-    before { SiteSetting.stubs(:default_email_mailing_list_mode).returns(true) }
+    before { SiteSetting.default_email_mailing_list_mode = true }
     let(:user) { Fabricate(:user) }
 
+    context "SiteSetting.max_emails_per_day_per_user" do
+
+      it 'stops sending mail once limit is reached' do
+        SiteSetting.max_emails_per_day_per_user = 2
+        post = Fabricate(:post)
+
+        user.email_logs.create(email_type: 'blah', to_address: user.email, user_id: user.id)
+        user.email_logs.create(email_type: 'blah', to_address: user.email, user_id: user.id)
+
+        Jobs::NotifyMailingListSubscribers.new.execute(post_id: post.id)
+        expect(EmailLog.where(user_id: user.id, skipped: true).count).to eq(1)
+      end
+    end
+
+    context "totally skipped if mailing list mode disabled" do
+
+      it "sends no email to the user" do
+        SiteSetting.disable_mailing_list_mode = true
+
+        post = Fabricate(:post)
+        Jobs::NotifyMailingListSubscribers.new.execute(post_id: post.id)
+        expect(EmailLog.count).to eq(0)
+      end
+    end
+
     context "with a valid post" do
       let!(:post) { Fabricate(:post, user: user) }
 

spec/jobs/user_email_spec.rb

@@ -193,6 +193,17 @@ describe Jobs::UserEmail do
         Jobs::UserEmail.new.execute(type: :user_mentioned, user_id: user.id, notification_id: notification.id)
       end
 
+      it "does not send notification if limit is reached" do
+        SiteSetting.max_emails_per_day_per_user = 2
+
+        user.email_logs.create(email_type: 'blah', to_address: user.email, user_id: user.id)
+        user.email_logs.create(email_type: 'blah', to_address: user.email, user_id: user.id)
+
+        Jobs::UserEmail.new.execute(type: :user_mentioned, user_id: user.id, notification_id: notification.id, post_id: post.id)
+
+        expect(EmailLog.where(user_id: user.id, skipped: true).count).to eq(1)
+      end
+
       it "doesn't send the mail if the user is using mailing list mode" do
         Email::Sender.any_instance.expects(:send).never
         user.user_option.update_column(:mailing_list_mode, true)
@@ -205,7 +216,7 @@ describe Jobs::UserEmail do
         # When post does not have a topic
         post = Fabricate(:post)
         post.topic.destroy
-        Jobs::UserEmail.new.execute(type: :user_mentioned, user_id: user.id, notification_type: "posted", post_id: post)
+        Jobs::UserEmail.new.execute(type: :user_mentioned, user_id: user.id, notification_type: "posted", post_id: post.id)
       end
 
       it "doesn't send the email if the post has been user deleted" do