```ruby
if ENV['COVERAGE']
  require 'simplecov'

  # Writes the coverage stat to a file to be used by Cane.
  class SimpleCov::Formatter::QualityFormatter
    def format(result)
      SimpleCov::Formatter::HTMLFormatter.new.format(result)
      File.open("coverage/covered_percent", "w") do |f|
        f.puts result.source_files.covered_percent.to_f
      end
    end
  end
  SimpleCov.formatter = SimpleCov::Formatter::QualityFormatter

  SimpleCov.start
end
```

Add filters and groups to Simplecov report
user
```ruby
if ENV['COVERAGE']
  require 'simplecov'

  # Writes the coverage stat to a file to be used by Cane.
  class SimpleCov::Formatter::QualityFormatter
    def format(result)
      SimpleCov::Formatter::HTMLFormatter.new.format(result)
      File.open("coverage/covered_percent", "w") do |f|
        f.puts result.source_files.covered_percent.to_f
      end
    end
  end
  SimpleCov.formatter = SimpleCov::Formatter::QualityFormatter

  SimpleCov.start do
    add_filter '/spec/'
    add_filter '/config/'
    add_filter '/vendor/'
    add_group 'Models', 'app/models'
    add_group 'Controllers', 'app/controllers'
    add_group 'Helpers', 'app/helpers'
    add_group 'Views', 'app/views'
    add_group 'Mailers', 'app/mailers'
  end
end
```
assistant