Extract listen watcher to separate gem

https://github.com/jonleighton/spring-watcher-listen

The reason to do this is that I want to minimise the amount of code
which needs to be maintained in the core spring project. I don't use the
listen watcher and therefore don't want to maintain it. If it's a
separate gem, others can maintain it on their own schedule.

Author: jonleighton

CHANGELOG.md

@@ -4,6 +4,8 @@
 * Watch `config/secrets.yml` by default. #289 - @morgoth
 * Change monkey-patched `Kernel.raise` from public to private (to match default Ruby behavior) #351 - @mattbrictson
 * Let application_id also respect RUBY_VERSION for the use case of switching between Ruby versions for a given Rails app - @methodmissing
+* Extract the 'listen' watcher to a separate `spring-watcher-listen`
+  gem. This allows it to be developed/maintained separately.
 
 ## 1.1.3
 

Gemfile

@@ -2,5 +2,3 @@ source 'https://rubygems.org'
 
 # Specify your gem's dependencies in spring.gemspec
 gemspec
-
-gem 'listen', "~> 1.0", :require => false

README.md

@@ -346,23 +346,10 @@ Spring.watch "config/some_config_file.yml"
 
 By default Spring polls the filesystem for changes once every 0.2 seconds. This
 method requires zero configuration, but if you find that it's using too
-much CPU, then you can turn on event-based file system listening:
-
-```ruby
-Spring.watch_method = :listen
-```
-
-You will need to add the [`listen` gem](https://github.com/guard/listen) to your `Gemfile`
-if you don't already have it:
-
-```ruby
-group :development do
-  gem 'listen', '~> 1.0'
-end
-```
-
-Note that Spring does not currently support version 2 of the listen gem.
-See pull request [#194](https://github.com/rails/spring/pull/194) for more details.
+much CPU, then you can use event-based file system listening by
+installing the
+[spring-watcher-listen](https://github.com/jonleighton/spring-watcher-listen)
+gem.
 
 ## Troubleshooting
 

lib/spring/commands.rb

@@ -32,8 +32,17 @@ def self.command(name)
   # then we need to be under bundler.
   require "bundler/setup"
 
-  Gem::Specification.map(&:name).grep(/^spring-commands-/).each do |command|
-    require command
+  # Auto-require any spring extensions which are in the Gemfile
+  Gem::Specification.map(&:name).grep(/^spring-/).each do |command|
+    begin
+      require command
+    rescue LoadError => error
+      if error.message.include?(command)
+        require command.gsub("-", "/")
+      else
+        raise
+      end
+    end
   end
 
   config = File.expand_path("./config/spring.rb")

lib/spring/test/acceptance_test.rb

@@ -16,8 +16,13 @@ def rails_version
         ENV['RAILS_VERSION'] || '~> 4.0.0'
       end
 
+      # Extension point for spring-watchers-listen
+      def generator_klass
+        Spring::Test::ApplicationGenerator
+      end
+
       def generator
-        @@generator ||= Spring::Test::ApplicationGenerator.new(rails_version)
+        @@generator ||= generator_klass.new(rails_version)
       end
 
       def app

lib/spring/test/application_generator.rb

@@ -10,8 +10,12 @@ def initialize(version_constraint)
         @bundled            = false
       end
 
+      def test_root
+        Pathname.new Spring::Test.root
+      end
+
       def root
-        "#{Spring::Test.root}/apps/rails-#{version.major}-#{version.minor}-spring-#{Spring::VERSION}"
+        test_root.join("apps/rails-#{version.major}-#{version.minor}-spring-#{Spring::VERSION}")
       end
 
       def system(command)
@@ -25,41 +29,40 @@ def system(command)
         puts if ENV["SPRING_DEBUG"]
       end
 
-      # Sporadic SSL errors keep causing test failures so there are anti-SSL workarounds here
       def generate
-        Bundler.with_clean_env do
-          system("gem list rails --installed --version '#{version_constraint}' || " \
-                   "gem install rails --clear-sources --source http://rubygems.org --version '#{version_constraint}'")
-
-          @version = RailsVersion.new(`ruby -e 'puts Gem::Specification.find_by_name("rails", "#{version_constraint}").version'`.chomp)
+        Bundler.with_clean_env { generate_files }
+        install_spring
+        generate_scaffold
+      end
 
-          skips = %w(--skip-bundle --skip-javascript --skip-sprockets)
-          skips << "--skip-spring" if version.bundles_spring?
+      # Sporadic SSL errors keep causing test failures so there are anti-SSL workarounds here
+      def generate_files
+        system("gem list rails --installed --version '#{version_constraint}' || " \
+                 "gem install rails --clear-sources --source http://rubygems.org --version '#{version_constraint}'")
 
-          system("rails _#{version}_ new #{application.root} #{skips.join(' ')}")
-          raise "application generation failed" unless application.exists?
+        @version = RailsVersion.new(`ruby -e 'puts Gem::Specification.find_by_name("rails", "#{version_constraint}").version'`.chomp)
 
-          FileUtils.mkdir_p(application.gem_home)
-          FileUtils.mkdir_p(application.user_home)
-          FileUtils.rm_rf(application.path("test/performance"))
+        skips = %w(--skip-bundle --skip-javascript --skip-sprockets)
+        skips << "--skip-spring" if version.bundles_spring?
 
-          File.write(application.gemfile, "#{application.gemfile.read}gem 'spring', '#{Spring::VERSION}'\n")
+        system("rails _#{version}_ new #{application.root} #{skips.join(' ')}")
+        raise "application generation failed" unless application.exists?
 
-          if version.needs_testunit?
-            File.write(application.gemfile, "#{application.gemfile.read}gem 'spring-commands-testunit'\n")
-          end
+        FileUtils.mkdir_p(application.gem_home)
+        FileUtils.mkdir_p(application.user_home)
+        FileUtils.rm_rf(application.path("test/performance"))
 
-          File.write(application.gemfile, application.gemfile.read.sub("https://rubygems.org", "http://rubygems.org"))
+        File.write(application.gemfile, "#{application.gemfile.read}gem 'spring', '#{Spring::VERSION}'\n")
 
-          if application.path("bin").exist?
-            FileUtils.cp_r(application.path("bin"), application.path("bin_original"))
-          end
+        if version.needs_testunit?
+          File.write(application.gemfile, "#{application.gemfile.read}gem 'spring-commands-testunit'\n")
         end
 
-        install_spring
+        File.write(application.gemfile, application.gemfile.read.sub("https://rubygems.org", "http://rubygems.org"))
 
-        application.run! "bundle exec rails g scaffold post title:string"
-        application.run! "bundle exec rake db:migrate db:test:clone"
+        if application.path("bin").exist?
+          FileUtils.cp_r(application.path("bin"), application.path("bin_original"))
+        end
       end
 
       def generate_if_missing
@@ -69,8 +72,7 @@ def generate_if_missing
       def install_spring
         return if @installed
 
-        system("gem build spring.gemspec 2>&1")
-        application.run! "gem install ../../../spring-#{Spring::VERSION}.gem", timeout: nil
+        build_and_install_gems
 
         application.bundle
 
@@ -84,10 +86,36 @@ def install_spring
         @installed = true
       end
 
+      def manually_built_gems
+        %w(spring)
+      end
+
+      def build_and_install_gems
+        manually_built_gems.each do |name|
+          spec = Gem::Specification.find_by_name(name)
+
+          FileUtils.cd(spec.gem_dir) do
+            FileUtils.rm(Dir.glob("#{name}-*.gem"))
+            system("gem build #{name}.gemspec 2>&1")
+          end
+
+          application.run! "gem install #{spec.gem_dir}/#{name}-*.gem", timeout: nil
+        end
+      end
+
       def copy_to(path)
         system("rm -rf #{path}")
         system("cp -r #{application.root} #{path}")
       end
+
+      def generate_scaffold
+        application.run! "bundle exec rails g scaffold post title:string"
+        application.run! "bundle exec rake db:migrate db:test:clone"
+      end
+
+      def gemspec(name)
+        "#{Gem::Specification.find_by_name(name).gem_dir}/#{name}.gemspec"
+      end
     end
   end
 end

lib/spring/version.rb

@@ -1,3 +1,3 @@
 module Spring
-  VERSION = "1.1.3"
+  VERSION = "1.2.0"
 end

lib/spring/watcher.rb

@@ -9,15 +9,11 @@ class << self
   end
 
   def self.watch_method=(method)
-    case method
-    when :polling
-      require_relative "watcher/polling"
-      @watch_method = Watcher::Polling
-    when :listen
-      require_relative "watcher/listen"
-      @watch_method = Watcher::Listen
-    else
+    if method.is_a?(Class)
       @watch_method = method
+    else
+      require "spring/watcher/#{method}"
+      @watch_method = Watcher.const_get(method.to_s.gsub(/(^.|_.)/) { $1[-1].upcase })
     end
   end
 

lib/spring/watcher/listen.rb

@@ -1,52 +1,6 @@
 require "helper"
 require "spring/test/watcher_test"
 require "spring/watcher/polling"
-require "spring/watcher/listen"
-
-class ListenWatcherTest < Spring::Test::WatcherTest
-  def watcher_class
-    Spring::Watcher::Listen
-  end
-
-  test "root directories" do
-    begin
-      other_dir_1 = File.realpath(Dir.mktmpdir)
-      other_dir_2 = File.realpath(Dir.mktmpdir)
-      File.write("#{other_dir_1}/foo", "foo")
-      File.write("#{dir}/foo", "foo")
-
-      watcher.add "#{other_dir_1}/foo"
-      watcher.add other_dir_2
-      watcher.add "#{dir}/foo"
-
-      assert_equal [dir, other_dir_1, other_dir_2].sort, watcher.base_directories.sort
-    ensure
-      FileUtils.rmdir other_dir_1
-      FileUtils.rmdir other_dir_2
-    end
-  end
-
-  test "root directories with a root subpath directory" do
-    begin
-      other_dir_1 = "#{dir}_other"
-      other_dir_2 = "#{dir}_core"
-      # same subpath as dir but with _other or _core appended
-      FileUtils::mkdir_p(other_dir_1)
-      FileUtils::mkdir_p(other_dir_2)
-      File.write("#{other_dir_1}/foo", "foo")
-      File.write("#{other_dir_2}/foo", "foo")
-      File.write("#{dir}/foo", "foo")
-
-      watcher.add "#{other_dir_1}/foo"
-      watcher.add other_dir_2
-
-      assert_equal [dir, other_dir_1, other_dir_2].sort, watcher.base_directories.sort
-    ensure
-      FileUtils.rmdir other_dir_1
-      FileUtils.rmdir other_dir_2
-    end
-  end
-end
 
 class PollingWatcherTest < Spring::Test::WatcherTest
   def watcher_class