[STORE] Added the Naming module

Provides getting Ruby class from Elasticsearch type and vice versa,
ID from the document (Hash), as well as setting the `klass`
for the whole Repository instance.

Author: karmi

elasticsearch-persistence/elasticsearch-persistence.gemspec

@@ -22,6 +22,7 @@ Gem::Specification.new do |s|
   s.rdoc_options      = [ "--charset=UTF-8" ]
 
   s.add_dependency "elasticsearch",       '> 0.4'
+  s.add_dependency "active_support"
 
   s.add_development_dependency "bundler", "~> 1.5"
   s.add_development_dependency "rake"

elasticsearch-persistence/lib/elasticsearch/persistence.rb

@@ -1,8 +1,11 @@
 require 'elasticsearch'
 
+require 'active_support/inflector'
+
 require 'elasticsearch/persistence/version'
 
 require 'elasticsearch/persistence/client'
+require 'elasticsearch/persistence/repository/naming'
 require 'elasticsearch/persistence/repository'
 
 require 'elasticsearch/persistence/repository/class'

elasticsearch-persistence/lib/elasticsearch/persistence/repository.rb

@@ -3,6 +3,7 @@ module Persistence
 
     module Repository
       include Elasticsearch::Persistence::Client
+      include Elasticsearch::Persistence::Repository::Naming
 
       def new(options={}, &block)
         Elasticsearch::Persistence::Repository::Class.new options, &block

elasticsearch-persistence/lib/elasticsearch/persistence/repository/naming.rb

@@ -0,0 +1,32 @@
+module Elasticsearch
+  module Persistence
+    module Repository
+
+      module Naming
+        def klass
+          @klass
+        end
+
+        def klass=klass
+          @klass = klass
+        end
+
+        def __get_klass_from_type(type)
+          klass = type.classify
+          klass.constantize
+        rescue NameError => e
+          raise NameError, "Attempted to get class '#{klass}' from the '#{type}' type, but no such class can be found."
+        end
+
+        def __get_type_from_class(klass)
+          klass.to_s.underscore
+        end
+
+        def __get_id_from_document(document)
+          document[:id] || document['id'] || document[:_id] || document['_id']
+        end
+      end
+
+    end
+  end
+end

elasticsearch-persistence/test/unit/repository_naming_test.rb

@@ -0,0 +1,64 @@
+require 'test_helper'
+
+class Elasticsearch::Persistence::RepositoryNamingTest < Test::Unit::TestCase
+  context "The repository naming" do
+    # Fake class for the naming tests
+    class ::Foobar; end
+    class ::FooBar; end
+    module ::Foo; class Bar; end; end
+
+    setup do
+      @shoulda_subject = Class.new() { include Elasticsearch::Persistence::Repository::Naming }.new
+    end
+
+    context "get Ruby class from the Elasticsearch type" do
+      should "get a simple class" do
+        assert_equal Foobar, subject.__get_klass_from_type('foobar')
+      end
+      should "get a camelcased class" do
+        assert_equal FooBar, subject.__get_klass_from_type('foo_bar')
+      end
+      should "get a namespaced class" do
+        assert_equal Foo::Bar, subject.__get_klass_from_type('foo/bar')
+      end
+      should "re-raise a NameError exception" do
+        assert_raise NameError do
+          subject.__get_klass_from_type('foobarbazbam')
+        end
+      end
+    end
+
+    context "get Elasticsearch type from the Ruby class" do
+      should "encode a simple class" do
+        assert_equal 'foobar', subject.__get_type_from_class(Foobar)
+      end
+      should "encode a camelcased class" do
+        assert_equal 'foo_bar', subject.__get_type_from_class(FooBar)
+      end
+      should "encode a namespaced class" do
+        assert_equal 'foo/bar', subject.__get_type_from_class(Foo::Bar)
+      end
+    end
+
+    context "get an ID from the document" do
+      should "get an ID from Hash" do
+        assert_equal 1, subject.__get_id_from_document(id: 1)
+        assert_equal 1, subject.__get_id_from_document(_id: 1)
+        assert_equal 1, subject.__get_id_from_document('id'  => 1)
+        assert_equal 1, subject.__get_id_from_document('_id' => 1)
+      end
+    end
+
+    context " document class name" do
+      should "be nil by default" do
+        assert_nil subject.klass
+      end
+
+      should "be settable" do
+        subject.klass = Foobar
+        assert_equal Foobar, subject.klass
+      end
+    end
+
+  end
+end