Fix possible duplication of AspectVisibility

No uniqueness control on AspectVisibility resulted in possible having
multiple AspectVisibility objects in the DB for the same aspect and
shareable which doesn't make sense. Introduce uniqueness validation
and fix up tests where duplication happened.

app/models/aspect_visibility.rb

@@ -10,4 +10,5 @@ class AspectVisibility < ActiveRecord::Base
   belongs_to :shareable, :polymorphic => true
   validates :shareable, :presence => true
 
+  validates :aspect, uniqueness: {scope: %i(shareable_id shareable_type)}
 end

spec/integration/mentioning_spec.rb

@@ -43,9 +43,9 @@ describe 'mentioning', :type => :request do
     expect(users_connected?(@user1, @user3)).to be false
 
     status_msg = nil
-    expect do
+    expect {
       status_msg = @user1.post(:status_message, {text: text_mentioning(@user3), to: default_aspect})
-    end.to change(Post, :count).by(1)
+    }.to change(Post, :count).by(1).and change(AspectVisibility, :count).by(1)
 
     expect(status_msg).not_to be_nil
     expect(status_msg.public?).to be false

spec/models/aspect_visibility_spec.rb

@@ -0,0 +1,32 @@
+require "spec_helper"
+
+describe AspectVisibility, type: :model do
+  let(:status_message) { FactoryGirl.create(:status_message) }
+  let(:aspect) { FactoryGirl.create(:aspect) }
+  let(:status_message_in_aspect) { FactoryGirl.create(:status_message_in_aspect) }
+  let(:photo_with_same_id) {
+    Photo.find_by_id(status_message_in_aspect.id) || FactoryGirl.create(:photo, id: status_message_in_aspect.id)
+  }
+
+  describe ".create" do
+    it "creates object when attributes are fine" do
+      expect {
+        AspectVisibility.create(shareable: status_message, aspect: aspect)
+      }.to change(AspectVisibility, :count).by(1)
+    end
+
+    it "doesn't allow duplicating objects" do
+      expect {
+        AspectVisibility
+          .create(shareable: status_message_in_aspect, aspect: status_message_in_aspect.aspects.first)
+          .save!
+      }.to raise_error(ActiveRecord::RecordInvalid)
+    end
+
+    it "makes difference between shareable types" do
+      expect {
+        AspectVisibility.create(shareable: photo_with_same_id, aspect: status_message_in_aspect.aspects.first).save!
+      }.not_to raise_error
+    end
+  end
+end

spec/support/user_methods.rb

@@ -16,7 +16,6 @@ class User
       if p.save!
         self.aspects.reload
 
-        add_to_streams(p, aspects)
         dispatch_opts = {
           url: Rails.application.routes.url_helpers.post_url(
             p,