--require option

Use the --require (or -r) option to specify a file to require before running specs.

Using the --require option

Given a file named "logging_formatter.rb" with:

require "rspec/core/formatters/base_text_formatter"
require 'delegate'

class LoggingFormatter < RSpec::Core::Formatters::BaseTextFormatter
  RSpec::Core::Formatters.register self, :dump_summary

  def initialize(output)
    super LoggingIO.new(output)
  end

  class LoggingIO < SimpleDelegator
    def initialize(output)
      @file = File.new('rspec.log', 'w')
      super
    end

    def puts(*args)
      [@file, __getobj__].each { |out| out.puts(*args) }
    end

    def close
      @file.close
    end
  end
end

And a file named "spec/example_spec.rb" with:

RSpec.describe "an embarrassing situation" do
  it "happens to everyone" do
  end
end

When I run rspec --require ./logging_formatter.rb --format LoggingFormatter

Then the output should contain "1 example, 0 failures"

And the file "rspec.log" should contain "1 example, 0 failures"

And the exit status should be 0.