Diary entry comment subscriptions

app/views/diary_entry/view.html.erb

@@ -21,7 +21,7 @@
     <%= richtext_area :diary_comment, :body, :cols => 80, :rows => 15 %>
     <%= submit_tag t('diary_entry.view.save_button') %>
   <% end %>
-  <% if @user and @entry.subscribers and @entry.subscribers.exists?(@user.id) %>
+  <% if @user and @entry.subscribers.exists?(@user.id) %>
     <div class="diary-subscribe-buttons"><%= link_to t('javascripts.changesets.show.unsubscribe'), diary_entry_unsubscribe_path(:display_name => @entry.user.display_name, :id => @entry.id), :method => :post, :class => :button %></div>
   <% elsif @user %>
     <div class="diary-subscribe-buttons"><%= link_to t('javascripts.changesets.show.subscribe'), diary_entry_subscribe_path(:display_name => @entry.user.display_name, :id => @entry.id), :method => :post, :class => :button %></div>

db/migrate/20161002153425_add_join_table_between_users_and_diary_entries.rb

@@ -1,11 +1,19 @@
+require "migrate"
+
 class AddJoinTableBetweenUsersAndDiaryEntries < ActiveRecord::Migration
-  def change
+  def self.up
     create_table :diary_entry_subscriptions, :id => false do |t|
       t.column :user_id, :bigint, :null => false
       t.column :diary_entry_id, :bigint, :null => false
     end
 
-    add_index :diary_entry_subscriptions, [:user_id, :diary_entry_id], :unique => true, :name => "index_diary_subscriptions_on_user_id_and_diary_entry_id"
+    add_primary_key :diary_entry_subscriptions, [:user_id, :diary_entry_id]
     add_index :diary_entry_subscriptions, [:diary_entry_id]
+    add_foreign_key :diary_entry_subscriptions, :diary_entries, :name => "diary_entry_subscriptions_diary_entry_id_fkey"
+    add_foreign_key :diary_entry_subscriptions, :users, :name => "diary_entry_subscriptions_user_id_fkey"
+  end
+
+  def self.down
+    drop_table :diary_entry_subscriptions
   end
 end

test/controllers/diary_entry_controller_test.rb

@@ -675,7 +675,7 @@ def test_subscribe_fail
     diary_entry = create(:diary_entry, :user_id => users(:normal_user).id)
 
     # not signed in
-    assert_no_difference "diary_entry.subscribers.count", 1 do
+    assert_no_difference "diary_entry.subscribers.count" do
       post :subscribe, :id => diary_entry.id, :display_name => diary_entry.user.display_name
     end
     assert_response :forbidden