FIX: create system message in user selected locale

DEV: refactor `create_from_system_user` to use `create` method

lib/system_message.rb

@@ -12,7 +12,8 @@ class SystemMessage
   end
 
   def self.create_from_system_user(recipient, type, params = {})
-    self.new(recipient).create_from_system_user(type, params)
+    params = params.merge(from_system: true)
+    self.new(recipient).create(type, params)
   end
 
   def initialize(recipient)
@@ -21,50 +22,47 @@ class SystemMessage
 
   def create(type, params = {})
     params = defaults.merge(params)
+    from_system = params[:from_system] || false
 
-    title = I18n.t("system_messages.#{type}.subject_template", params)
-    raw = I18n.t("system_messages.#{type}.text_body_template", params)
+    title = I18n.with_locale(@recipient.effective_locale) { I18n.t("system_messages.#{type}.subject_template", params) }
+    raw = I18n.with_locale(@recipient.effective_locale) { I18n.t("system_messages.#{type}.text_body_template", params) }
 
-    creator = PostCreator.new(Discourse.site_contact_user,
+    if from_system
+      user = Discourse.system_user
+      target_group_names = nil
+    else
+      user = Discourse.site_contact_user
+      target_group_names = Group.exists?(name: SiteSetting.site_contact_group_name) ? SiteSetting.site_contact_group_name : nil
+    end
+
+    creator = PostCreator.new(user,
                        title: title,
                        raw: raw,
                        archetype: Archetype.private_message,
                        target_usernames: @recipient.username,
-                       target_group_names: Group.exists?(name: SiteSetting.site_contact_group_name) ? SiteSetting.site_contact_group_name : nil,
+                       target_group_names: target_group_names,
                        subtype: TopicSubtype.system_message,
                        skip_validations: true)
 
-    post = creator.create
+    post = I18n.with_locale(@recipient.effective_locale) { creator.create }
+
     if creator.errors.present?
       raise StandardError, creator.errors.full_messages.join(" ")
     end
 
-    UserArchivedMessage.create!(user: Discourse.site_contact_user, topic: post.topic)
+    unless from_system
+      UserArchivedMessage.create!(user: Discourse.site_contact_user, topic: post.topic)
+    end
 
     post
   end
 
-  def create_from_system_user(type, params = {})
-    params = defaults.merge(params)
-
-    title = I18n.t("system_messages.#{type}.subject_template", params)
-    raw = I18n.t("system_messages.#{type}.text_body_template", params)
-
-    PostCreator.create!(Discourse.system_user,
-                       title: title,
-                       raw: raw,
-                       archetype: Archetype.private_message,
-                       target_usernames: @recipient.username,
-                       subtype: TopicSubtype.system_message,
-                       skip_validations: true)
-  end
-
   def defaults
     {
       site_name: SiteSetting.title,
       username: @recipient.username,
       user_preferences_url: "#{Discourse.base_url}/u/#{@recipient.username_lower}/preferences",
-      new_user_tips: I18n.t('system_messages.usage_tips.text_body_template', base_url: Discourse.base_url),
+      new_user_tips: I18n.with_locale(@recipient.effective_locale) { I18n.t('system_messages.usage_tips.text_body_template', base_url: Discourse.base_url) },
       site_password: "",
       base_url: Discourse.base_url,
     }

spec/components/system_message_spec.rb

@@ -30,6 +30,24 @@ describe SystemMessage do
       expect(UserArchivedMessage.where(user_id: admin.id, topic_id: topic.id).length).to eq(1)
     end
 
+    it 'can create a post from system user in user selected locale' do
+      SiteSetting.allow_user_locale = true
+      user_de = Fabricate(:user, locale: 'de')
+      system_user = Discourse.system_user
+
+      post = SystemMessage.create_from_system_user(user_de, :welcome_invite)
+      topic = post.topic
+
+      expect(post.valid?).to eq(true)
+      expect(topic).to be_private_message
+      expect(topic).to be_valid
+      expect(topic.title).to eq(I18n.with_locale(:de) { I18n.t("system_messages.welcome_invite.subject_template", site_name: SiteSetting.title) })
+      expect(topic.subtype).to eq(TopicSubtype.system_message)
+      expect(topic.allowed_users.include?(user_de)).to eq(true)
+      expect(topic.allowed_users.include?(system_user)).to eq(true)
+      expect(UserArchivedMessage.where(user_id: system_user.id, topic_id: topic.id).length).to eq(0)
+    end
+
     it 'should allow site_contact_group_name' do
       group = Fabricate(:group)
       SiteSetting.site_contact_group_name = group.name