From dc727627a645472a82d7678efb335bdd4d481167 Mon Sep 17 00:00:00 2001
From: fatkodima <fatkodima123@gmail.com>
Date: Thu, 29 Mar 2018 21:21:57 +0300
Subject: [PATCH] Add version to auditable_index

---
 CHANGELOG.md                                  |  3 ++-
 lib/audited/audit.rb                          |  2 +-
 .../add_version_to_auditable_index.rb         | 21 +++++++++++++++++++
 lib/generators/audited/templates/install.rb   |  2 +-
 lib/generators/audited/upgrade_generator.rb   |  4 ++++
 test/db/version_6.rb                          |  2 ++
 test/upgrade_generator_test.rb                | 10 +++++++++
 7 files changed, 41 insertions(+), 3 deletions(-)
 create mode 100644 lib/generators/audited/templates/add_version_to_auditable_index.rb

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2f885fe61..f8a4a5bf6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,7 +15,8 @@ Added
 
 Changed
 
-- None
+- Add version to auditable_index
+  [#427](https://github.com/collectiveidea/audited/pull/427)
 
 Fixed
 
diff --git a/lib/audited/audit.rb b/lib/audited/audit.rb
index 4d96d02c1..ff82e4e35 100644
--- a/lib/audited/audit.rb
+++ b/lib/audited/audit.rb
@@ -171,7 +171,7 @@ def self.collection_cache_key(collection = all, timestamp_column = :created_at)
     private
 
     def set_version_number
-      max = self.class.auditable_finder(auditable_id, auditable_type).descending.first.try(:version) || 0
+      max = self.class.auditable_finder(auditable_id, auditable_type).maximum(:version) || 0
       self.version = max + 1
     end
 
diff --git a/lib/generators/audited/templates/add_version_to_auditable_index.rb b/lib/generators/audited/templates/add_version_to_auditable_index.rb
new file mode 100644
index 000000000..79a4045d6
--- /dev/null
+++ b/lib/generators/audited/templates/add_version_to_auditable_index.rb
@@ -0,0 +1,21 @@
+class <%= migration_class_name %> < <%= migration_parent %>
+  def self.up
+    if index_exists?(:audits, [:auditable_type, :auditable_id], name: index_name)
+      remove_index :audits, name: index_name
+      add_index :audits, [:auditable_type, :auditable_id, :version], name: index_name
+    end
+  end
+
+  def self.down
+    if index_exists?(:audits, [:auditable_type, :auditable_id, :version], name: index_name)
+      remove_index :audits, name: index_name
+      add_index :audits, [:auditable_type, :auditable_id], name: index_name
+    end
+  end
+
+  private
+
+  def index_name
+    'auditable_index'
+  end
+end
diff --git a/lib/generators/audited/templates/install.rb b/lib/generators/audited/templates/install.rb
index 77bf46aa3..1d43f093c 100644
--- a/lib/generators/audited/templates/install.rb
+++ b/lib/generators/audited/templates/install.rb
@@ -17,7 +17,7 @@ def self.up
       t.column :created_at, :datetime
     end
 
-    add_index :audits, [:auditable_type, :auditable_id], :name => 'auditable_index'
+    add_index :audits, [:auditable_type, :auditable_id, :version], :name => 'auditable_index'
     add_index :audits, [:associated_type, :associated_id], :name => 'associated_index'
     add_index :audits, [:user_id, :user_type], :name => 'user_index'
     add_index :audits, :request_uuid
diff --git a/lib/generators/audited/upgrade_generator.rb b/lib/generators/audited/upgrade_generator.rb
index 91c87444c..d2b019704 100644
--- a/lib/generators/audited/upgrade_generator.rb
+++ b/lib/generators/audited/upgrade_generator.rb
@@ -58,6 +58,10 @@ def migrations_to_be_applied
         if indexes.any? { |i| i.columns == %w[associated_id associated_type] }
           yield :revert_polymorphic_indexes_order
         end
+
+        if indexes.any? { |i| i.columns == %w[auditable_type auditable_id] }
+          yield :add_version_to_auditable_index
+        end
       end
     end
   end
diff --git a/test/db/version_6.rb b/test/db/version_6.rb
index 776569606..281ea9227 100644
--- a/test/db/version_6.rb
+++ b/test/db/version_6.rb
@@ -14,4 +14,6 @@
     t.column :associated_id, :integer
     t.column :associated_type, :string
   end
+
+  add_index :audits, [:auditable_type, :auditable_id], name: 'auditable_index'
 end
diff --git a/test/upgrade_generator_test.rb b/test/upgrade_generator_test.rb
index 53ada067c..376710804 100644
--- a/test/upgrade_generator_test.rb
+++ b/test/upgrade_generator_test.rb
@@ -79,6 +79,16 @@ class UpgradeGeneratorTest < Rails::Generators::TestCase
     end
   end
 
+  test "should add 'version' to auditable_index" do
+    load_schema 6
+
+    run_generator %w(upgrade)
+
+    assert_migration "db/migrate/add_version_to_auditable_index.rb" do |content|
+      assert_match(/add_index :audits, \[:auditable_type, :auditable_id, :version\]/, content)
+    end
+  end
+
   test "generate migration with correct AR migration parent" do
     load_schema 1