```ruby
require 'date'

module Tech404
  module Index
    class Application < Sinatra::Base
      get '/' do
        @channel = Channel.first(name: 'general')
        @messages = @channel.messages.on_date(date).ascending
        content_type :html
        erb :messages
      end

      get '/:channel_name/?:date?' do
        @channel = Channel.first(name: params[:channel_name])
        @messages = @channel.messages.on_date(date).ascending
        content_type :html
        erb :messages
      end

      helpers do
        def date
          if params[:date]
            Date.strptime(params[:date], '%Y-%m-%d')
          else
            Date.today
          end
        end

        def channels
          Channel.indexing
        end

        def channel_path(channel_or_name, date = nil)
          name = case channel_or_name
                 when Channel
                   channel_or_name.name
                 when String
                   channel_or_name
                 end
          if date
            "/#{name}/#{date.strftime('%Y-%m-%d')}"
          else
            "/#{name}"
          end
        end

        def format_message(text)
          text = UserMentionFilter.apply(text)
          text = ChannelMentionFilter.apply(text)
          text
        end

        def user_name(user)
          user.real_name || user.name
        end
      end
    end
  end
end
```

Check for empty string names instead of nils
user
```ruby
require 'date'

module Tech404
  module Index
    class Application < Sinatra::Base
      get '/' do
        @channel = Channel.first(name: 'general')
        @messages = @channel.messages.on_date(date).ascending
        content_type :html
        erb :messages
      end

      get '/:channel_name/?:date?' do
        @channel = Channel.first(name: params[:channel_name])
        @messages = @channel.messages.on_date(date).ascending
        content_type :html
        erb :messages
      end

      helpers do
        def date
          if params[:date]
            Date.strptime(params[:date], '%Y-%m-%d')
          else
            Date.today
          end
        end

        def channels
          Channel.indexing
        end

        def channel_path(channel_or_name, date = nil)
          name = case channel_or_name
                 when Channel
                   channel_or_name.name
                 when String
                   channel_or_name
                 end
          if date
            "/#{name}/#{date.strftime('%Y-%m-%d')}"
          else
            "/#{name}"
          end
        end

        def format_message(text)
          text = UserMentionFilter.apply(text)
          text = ChannelMentionFilter.apply(text)
          text
        end

        def user_name(user)
          name = user.real_name.to_s
          name = user.name if name.empty?
          name
        end
      end
    end
  end
end
```
assistant