LastFailed for RSpec

last_failed_logger.rb

require 'rspec/core/formatters/progress_formatter'
class LastFailedLogger < RSpec::Core::Formatters::BaseFormatter

  def example_failed(example)
    super
    @all_examples_passed = false
    File.open("log/last_failed_spec.log", "w") do |f|
      f.write(example.location)
    end
  end

  def stop
    if @failure_count > 0
      FileUtils.rm("log/last_failed_spec.log")
    end
    super
  end

end

Rakefile

namespace :spec do
  require './last_failed_logger.rb'

  default_opts = ["--format progress", "--color", "--fail-fast", "-f LastFailedLogger"]

  RSpec::Core::RakeTask.new(:auto) do |t|
    if File.exists? "./log/last_failed_spec.log"
      $ran_last_failed_test = true
      t.rspec_opts = [*default_opts, "--tag ~wip"]
      t.pattern = File.open("./log/last_failed_spec.log").read
      FileUtils.rm "./log/last_failed_spec.log"
    else
      $ran_last_failed_test = false
      t.rspec_opts = [*default_opts, "--tag ~wip"]
    end
  end

  desc "Run all specs"
  RSpec::Core::RakeTask.new(:all) do |t|
    t.rspec_opts = [*default_opts]
  end


  desc "Run all specs that should pass"
  RSpec::Core::RakeTask.new(:ok) do |t|
    t.rspec_opts = [*default_opts, "--tag ~wip"]
  end
end

Rake::Task["spec:auto"].enhance do
  if $ran_last_failed_test
    STDOUT.puts
    STDOUT.puts "\e[32mLast failed example passed! Running all examples now...\e[0m"
    STDOUT.puts
    Rake::Task["spec:ok"].invoke
  end
end