Lightweight alternative to guard. Run rspec over spork as you code watching changes to your code base.

.watchr

def run_spec(file)
  unless File.exist?(file)
    puts "#{file} does not exist, no specs to run."
    return
  end

  puts "Running #{file}"
  system "bundle exec rspec #{file} --drb --colour"
  puts
end

# Obviously rerun tests when spec file is updated
watch("spec/.*/*_spec.rb") do |match|
  run_spec match[0]
end

# Run specs for app/ folder
watch("app/(.*/.*).rb") do |match|
  run_spec %{spec/#{match[1]}_spec.rb}
end

# Run specs for lib/ folder
watch("^lib/(.*/.*).rb") do |match|
  run_spec %{spec/lib/#{match[1]}_spec.rb}
end

Gemfile

group :development, :test do
  gem "watchr"
  gem "rb-fsevent" # If you are not on MacOSX: https://github.com/guard/guard#efficient-filesystem-handling
  gem "spork"
end

watchr.rake

desc "Run watchr"
task :watchr do
  fork do
    sh %{bundle exec spork}
  end
  sh %{bundle exec watchr .watchr}
end