Project: RSpec Core 3.0

Publisher: RSpec

custom formatters

RSpec ships with general purpose output formatters. You can tell RSpec which
one to use using the --format command line option.

When RSpec's built-in output formatters don't, however, give you everything
you need, you can write your own custom formatter and tell RSpec to use that
one instead. The simplest way is to subclass RSpec's BaseTextFormatter, and
then override just the methods that you want to modify.

Scenarios

Custom formatter

Given

a file named "custom_formatter.rb" with:

class CustomFormatter
  # This registers the notifications this formatter supports, and tells
  # us that this was written against the RSpec 3.x formatter API.
  RSpec::Core::Formatters.register self, :example_started

  def initialize(output)
    @output = output
  end

  def example_started(notification)
    @output << "example: " << notification.example.description
  end
end

And

a file named "example_spec.rb" with:

RSpec.describe "my group" do
  specify "my example" do
  end
end

When

I run rspec example_spec.rb --require ./custom_formatter.rb --format CustomFormatter

Then

the output should contain "example: my example"

And

the exit status should be 0

Last published about 7 years ago by myronmarston.

custom formatters

RSpec Core settings