FIX: automatically disable digests when enabling mailing list mode

app/services/user_updater.rb

@@ -70,14 +70,13 @@ class UserUpdater
       TagUser.batch_set(user, level, attributes[attribute])
     end
 
-
     save_options = false
 
     OPTION_ATTR.each do |attribute|
       if attributes.key?(attribute)
         save_options = true
 
-        if [true,false].include?(user.user_option.send(attribute))
+        if [true, false].include?(user.user_option.send(attribute))
           val = attributes[attribute].to_s == 'true'
           user.user_option.send("#{attribute}=", val)
         else
@@ -86,6 +85,9 @@ class UserUpdater
       end
     end
 
+    # automatically disable digests when mailing_list_mode is enabled
+    user.user_option.email_digests = false if user.user_option.mailing_list_mode
+
     fields = attributes[:custom_fields]
     if fields.present?
       user.custom_fields = user.custom_fields.merge(fields)

spec/services/user_updater_spec.rb

@@ -91,6 +91,19 @@ describe UserUpdater do
       expect(user.date_of_birth).to eq(date_of_birth.to_date)
     end
 
+    it "disables email_digests when enabling mailing_list_mode" do
+      user = Fabricate(:user)
+      updater = UserUpdater.new(acting_user, user)
+
+      val = updater.update(mailing_list_mode: true, email_digests: true)
+      expect(val).to be_truthy
+
+      user.reload
+
+      expect(user.user_option.email_digests).to eq false
+      expect(user.user_option.mailing_list_mode).to eq true
+    end
+
     context 'when sso overrides bio' do
       it 'does not change bio' do
         SiteSetting.enable_sso = true