Raise on INSERT in the PostgreSQLAdapter

raise_on_insert.rb

module ActiveRecord
  module ConnectionAdapters
    class PostgreSQLAdapter < AbstractAdapter
      def execute(sql, name = nil) 
        if sql.split(' ').include?("INSERT")
          raise "\nDon't write to the database in your unit tests\n #{sql}".red
        end
        log(sql, name) do
          if @async
            @connection.async_exec(sql)
          else
            @connection.exec(sql)
          end
        end
      end
    end
  end
end