adding tests for the christener

spec/sql/christener_spec.rb

+require 'spec_helper'
+
+module Arel
+  module Sql
+    describe "Christener" do
+      it "returns the same name with two table objects" do
+        christener = Christener.new
+        table = Table.new 'users'
+        table2 = Table.new 'users'
+        christener.name_for(table).should == 'users'
+        christener.name_for(table2).should == 'users'
+      end
+
+      it "returns the first name" do
+        christener = Christener.new
+        table = Table.new 'users'
+        table2 = Table.new 'pictures'
+        christener.name_for(table).should == 'users'
+        christener.name_for(table2).should == 'pictures'
+        christener.name_for(table).should == 'users'
+      end
+
+      it "returns a unique name for an alias" do
+        christener = Christener.new
+        table = Table.new 'users'
+        table2 = Table.new 'users', :as => 'friends'
+        christener.name_for(table).should == 'users'
+        christener.name_for(table2).should == 'friends'
+      end
+
+      it "returns a unique name for an alias with same name" do
+        christener = Christener.new
+        table = Table.new 'users'
+        table2 = Table.new 'friends', :as => 'users'
+        christener.name_for(table).should == 'users'
+        christener.name_for(table2).should == 'users_2'
+      end
+
+      it "returns alias name" do
+        christener = Christener.new
+        table = Table.new 'users'
+        aliaz = Alias.new table
+
+        christener.name_for(table).should == 'users'
+        christener.name_for(aliaz).should == 'users_2'
+      end
+
+      it "returns alias first" do
+        christener = Christener.new
+        table = Table.new 'users'
+        aliaz = Alias.new table
+
+        christener.name_for(aliaz).should == 'users'
+        christener.name_for(table).should == 'users_2'
+      end
+
+      it "returns externalization name" do
+        christener = Christener.new
+        table = Table.new 'users'
+        ext = Externalization.new table
+
+        christener.name_for(table).should == 'users'
+        christener.name_for(ext).should == 'users_external'
+      end
+
+      it "returns aliases externalizations and tables" do
+        christener = Christener.new
+        table = Table.new 'users'
+        aliaz = Alias.new table
+        ext = Externalization.new table
+
+        christener.name_for(table).should == 'users'
+        christener.name_for(aliaz).should == 'users_2'
+        christener.name_for(ext).should == 'users_external'
+      end
+    end
+  end
+end