Simple rake script to run failed specs from CircleCi on your computer

Gemfile

group :development do
  gem 'circleci', require: false
end

spec.rake

namespace :spec do
  desc <<-DESC
    Run specs that failed for a CircleCi build
    Uses bin/rspec as driver

    Can be run as `bin/rake spec:circle_ci[build_id]`
  DESC
  task :circle_ci, [ :circle_ci_build_id ] do |task, task_args|
    require 'circleci' # Cuz we dont wanna pollute the rest of the stack

    CircleCi.configure do |config|
      config.token = ENV['CIRCLE_CI_API_TOKEN']
    end

    # The CircleCi gem add webmock into env.development, which blocks
    # remote calls when in development
    # So...don't run this as part of a test suite
    WebMock.disable!

    response = CircleCi::Build.tests(
      'my_github_organization',
      'my_github_repo',
      task_args[ :circle_ci_build_id ]
    )

    tests = response.body[ "tests" ]
    files = tests.select{ |test| test["result"] == "failure" }
      .map{ |test| test[ "file" ] }

    sh "bin/rspec #{ files.to_a.join ' ' }"
  end
end

So simple, thanks to the https://github.com/mtchavez/circleci gem