Update the default db_adapter to :postgresql like Rails (instead of :pg)

This is backward compatible

Author: Nicolas Rodriguez

lib/ajax-datatables-rails/config.rb

@@ -4,7 +4,7 @@ module AjaxDatatablesRails
 
   # configure AjaxDatatablesRails global settings
   #   AjaxDatatablesRails.configure do |config|
-  #     config.db_adapter = :pg
+  #     config.db_adapter = :postgresql
   #   end
   def self.configure
     yield @config ||= AjaxDatatablesRails::Configuration.new
@@ -19,6 +19,6 @@ class Configuration
     include ActiveSupport::Configurable
 
     config_accessor(:orm) { :active_record }
-    config_accessor(:db_adapter) { :pg }
+    config_accessor(:db_adapter) { :postgresql }
   end
 end

spec/ajax-datatables-rails/configuration_spec.rb

@@ -24,8 +24,8 @@
       expect(config.orm).to eq(:active_record)
     end
 
-    it 'default db_adapter should :pg (postgresql)' do
-      expect(config.db_adapter).to eq(:pg)
+    it 'default db_adapter should :postgresql' do
+      expect(config.db_adapter).to eq(:postgresql)
     end
   end
 

spec/ajax-datatables-rails/orm/active_record_filter_records_spec.rb

@@ -127,6 +127,11 @@
       expect(column.send(:typecast)).to eq('VARCHAR')
     end
 
+    it 'returns VARCHAR if :db_adapter is :postgre' do
+      allow_any_instance_of(AjaxDatatablesRails::Configuration).to receive(:db_adapter) { :postgresql }
+      expect(column.send(:typecast)).to eq('VARCHAR')
+    end
+
     it 'returns CHAR if :db_adapter is :mysql2' do
       allow_any_instance_of(AjaxDatatablesRails::Configuration).to receive(:db_adapter) { :mysql2 }
       expect(column.send(:typecast)).to eq('CHAR')