Merge branch 'master' into treewip

* master: (113 commits)
  remove useless method
  Updated file documentation [ci skip]
  changes caching guide to add note on weak etags
  Don't put config.action_mailer.perform_caching entry twice in development.rb
  Fix wording and wrong reference
  Add Ruby formatting to CHANGELOG entry
  Fix ActionView's cache section reference
  Do not define methods in the included block
  Add caching guide in ActionMailer basics
  Add ActionMailer configuration options
  Preparing for 5.0.0.beta3 release
  Update 5.0 release notes
  Enable tmp_restart plugin for puma
  Prep release for Rails 5 beta3
  [ci skip] Move collection caching changelog entry.
  Ensure `drop_table` even if tests failure or interrupted
  :bomb: run the test @rafaelfranca :angry:
  Remove changelog entry for reverted commit
  Add CHANGELOG for https://github.com/rails/rails/pull/23734 [ci skip]
  No need CHANGELOG entry for #23849.
  ...

10 files changed, 289 insertions, 11 deletions

diff --git a/actionmailer/CHANGELOG.md b/actionmailer/CHANGELOG.md
index 1531f2b471..604e332dad 100644
--- a/actionmailer/CHANGELOG.md
+++ b/actionmailer/CHANGELOG.md
@@ -1,3 +1,11 @@
+## Rails 5.0.0.beta3 (February 24, 2016) ##
+
+*   Add support to fragment cache in Action Mailer.
+
+    Now you can use fragment caching in your mailers views.
+
+    *Stan Lo*
+
 *   Reset `ActionMailer::Base.deliveries` after every test in
     `ActionDispatch::IntegrationTest`.
 
diff --git a/actionmailer/lib/action_mailer/base.rb b/actionmailer/lib/action_mailer/base.rb
index 4259eb0bee..559cd06d91 100644
--- a/actionmailer/lib/action_mailer/base.rb
+++ b/actionmailer/lib/action_mailer/base.rb
@@ -430,6 +430,7 @@ module ActionMailer
     include AbstractController::Translation
     include AbstractController::AssetPaths
     include AbstractController::Callbacks
+    include AbstractController::Caching
 
     include ActionView::Layouts
 
@@ -947,6 +948,18 @@ module ActionMailer
       container.add_part(part)
     end
 
+    # This and #instrument_name is for caching instrument
+    def instrument_payload(key)
+      {
+        mailer: mailer_name,
+        key: key
+      }
+    end
+
+    def instrument_name
+      "action_mailer"
+    end
+
     ActiveSupport.run_load_hooks(:action_mailer, self)
   end
 end
diff --git a/actionmailer/lib/action_mailer/gem_version.rb b/actionmailer/lib/action_mailer/gem_version.rb
index a1ee5fb238..cbe5fc3e64 100644
--- a/actionmailer/lib/action_mailer/gem_version.rb
+++ b/actionmailer/lib/action_mailer/gem_version.rb
@@ -8,7 +8,7 @@ module ActionMailer
     MAJOR = 5
     MINOR = 0
     TINY  = 0
-    PRE   = "beta2"
+    PRE   = "beta3"
 
     STRING = [MAJOR, MINOR, TINY, PRE].compact.join(".")
   end
diff --git a/actionmailer/lib/action_mailer/railtie.rb b/actionmailer/lib/action_mailer/railtie.rb
index 22390c4953..215d0199af 100644
--- a/actionmailer/lib/action_mailer/railtie.rb
+++ b/actionmailer/lib/action_mailer/railtie.rb
@@ -25,6 +25,7 @@ module ActionMailer
       options.javascripts_dir ||= paths["public/javascripts"].first
       options.stylesheets_dir ||= paths["public/stylesheets"].first
       options.show_previews = Rails.env.development? if options.show_previews.nil?
+      options.cache_store ||= Rails.cache
 
       if options.show_previews
         options.preview_path  ||= defined?(Rails.root) ? "#{Rails.root}/test/mailers/previews" : nil
@@ -45,13 +46,6 @@ module ActionMailer
 
         options.each { |k,v| send("#{k}=", v) }
 
-        if options.show_previews
-          app.routes.prepend do
-            get '/rails/mailers'         => "rails/mailers#index"
-            get '/rails/mailers/*path'   => "rails/mailers#preview"
-          end
-        end
-
         ActionDispatch::IntegrationTest.send :include, ActionMailer::TestCase::ClearTestDeliveries
       end
     end
@@ -62,9 +56,18 @@ module ActionMailer
       end
     end
 
-    config.after_initialize do
-      if ActionMailer::Base.preview_path
-        ActiveSupport::Dependencies.autoload_paths << ActionMailer::Base.preview_path
+    config.after_initialize do |app|
+      options = app.config.action_mailer
+
+      if options.show_previews
+        app.routes.prepend do
+          get '/rails/mailers'         => "rails/mailers#index", internal: true
+          get '/rails/mailers/*path'   => "rails/mailers#preview", internal: true
+        end
+
+        if options.preview_path
+          ActiveSupport::Dependencies.autoload_paths << options.preview_path
+        end
       end
     end
   end
diff --git a/actionmailer/test/caching_test.rb b/actionmailer/test/caching_test.rb
new file mode 100644
index 0000000000..b4344eb167
--- /dev/null
+++ b/actionmailer/test/caching_test.rb
@@ -0,0 +1,229 @@
+require 'fileutils'
+require 'abstract_unit'
+require 'mailers/base_mailer'
+require 'mailers/caching_mailer'
+
+CACHE_DIR = 'test_cache'
+# Don't change '/../temp/' cavalierly or you might hose something you don't want hosed
+FILE_STORE_PATH = File.join(File.dirname(__FILE__), '/../temp/', CACHE_DIR)
+
+class FragmentCachingMailer < ActionMailer::Base
+  abstract!
+
+  def some_action; end
+end
+
+class BaseCachingTest < ActiveSupport::TestCase
+  def setup
+    super
+    @store = ActiveSupport::Cache::MemoryStore.new
+    @mailer = FragmentCachingMailer.new
+    @mailer.perform_caching = true
+    @mailer.cache_store = @store
+  end
+
+  def test_fragment_cache_key
+    assert_equal 'views/what a key', @mailer.fragment_cache_key('what a key')
+  end
+end
+
+class FragmentCachingTest < BaseCachingTest
+  def test_read_fragment_with_caching_enabled
+    @store.write('views/name', 'value')
+    assert_equal 'value', @mailer.read_fragment('name')
+  end
+
+  def test_read_fragment_with_caching_disabled
+    @mailer.perform_caching = false
+    @store.write('views/name', 'value')
+    assert_nil @mailer.read_fragment('name')
+  end
+
+  def test_fragment_exist_with_caching_enabled
+    @store.write('views/name', 'value')
+    assert @mailer.fragment_exist?('name')
+    assert !@mailer.fragment_exist?('other_name')
+  end
+
+  def test_fragment_exist_with_caching_disabled
+    @mailer.perform_caching = false
+    @store.write('views/name', 'value')
+    assert !@mailer.fragment_exist?('name')
+    assert !@mailer.fragment_exist?('other_name')
+  end
+
+  def test_write_fragment_with_caching_enabled
+    assert_nil @store.read('views/name')
+    assert_equal 'value', @mailer.write_fragment('name', 'value')
+    assert_equal 'value', @store.read('views/name')
+  end
+
+  def test_write_fragment_with_caching_disabled
+    assert_nil @store.read('views/name')
+    @mailer.perform_caching = false
+    assert_equal 'value', @mailer.write_fragment('name', 'value')
+    assert_nil @store.read('views/name')
+  end
+
+  def test_expire_fragment_with_simple_key
+    @store.write('views/name', 'value')
+    @mailer.expire_fragment 'name'
+    assert_nil @store.read('views/name')
+  end
+
+  def test_expire_fragment_with_regexp
+    @store.write('views/name', 'value')
+    @store.write('views/another_name', 'another_value')
+    @store.write('views/primalgrasp', 'will not expire ;-)')
+
+    @mailer.expire_fragment(/name/)
+
+    assert_nil @store.read('views/name')
+    assert_nil @store.read('views/another_name')
+    assert_equal 'will not expire ;-)', @store.read('views/primalgrasp')
+  end
+
+  def test_fragment_for
+    @store.write('views/expensive', 'fragment content')
+    fragment_computed = false
+
+    view_context = @mailer.view_context
+
+    buffer = 'generated till now -> '.html_safe
+    buffer << view_context.send(:fragment_for, 'expensive') { fragment_computed = true }
+
+    assert !fragment_computed
+    assert_equal 'generated till now -> fragment content', buffer
+  end
+
+  def test_html_safety
+    assert_nil @store.read('views/name')
+    content = 'value'.html_safe
+    assert_equal content, @mailer.write_fragment('name', content)
+
+    cached = @store.read('views/name')
+    assert_equal content, cached
+    assert_equal String, cached.class
+
+    html_safe = @mailer.read_fragment('name')
+    assert_equal content, html_safe
+    assert html_safe.html_safe?
+  end
+end
+
+class FunctionalFragmentCachingTest < BaseCachingTest
+  def setup
+    super
+    @store = ActiveSupport::Cache::MemoryStore.new
+    @mailer = CachingMailer.new
+    @mailer.perform_caching = true
+    @mailer.cache_store = @store
+  end
+
+  def test_fragment_caching
+    email = @mailer.fragment_cache
+    expected_body = "\"Welcome\""
+
+    assert_match expected_body, email.body.encoded
+    assert_match "\"Welcome\"",
+      @store.read("views/caching/#{template_digest("caching_mailer/fragment_cache")}")
+  end
+
+  def test_fragment_caching_in_partials
+    email = @mailer.fragment_cache_in_partials
+    assert_match(/Old fragment caching in a partial/, email.body.encoded)
+
+    assert_match("Old fragment caching in a partial",
+      @store.read("views/caching/#{template_digest("caching_mailer/_partial")}"))
+  end
+
+  def test_skip_fragment_cache_digesting
+    email = @mailer.skip_fragment_cache_digesting
+    expected_body = "No Digest"
+
+    assert_match expected_body, email.body.encoded
+    assert_match expected_body, @store.read("views/no_digest")
+  end
+
+  private
+
+    def template_digest(name)
+      ActionView::Digestor.digest(name: name, finder: @mailer.lookup_context)
+    end
+end
+
+class CacheHelperOutputBufferTest < BaseCachingTest
+
+  class MockController
+    def read_fragment(name, options)
+      return false
+    end
+
+    def write_fragment(name, fragment, options)
+      fragment
+    end
+  end
+
+  def setup
+    super
+  end
+
+  def test_output_buffer
+    output_buffer = ActionView::OutputBuffer.new
+    controller = MockController.new
+    cache_helper = Class.new do
+      def self.controller; end;
+      def self.output_buffer; end;
+      def self.output_buffer=; end;
+    end
+    cache_helper.extend(ActionView::Helpers::CacheHelper)
+
+    cache_helper.stub :controller, controller do
+      cache_helper.stub :output_buffer, output_buffer do
+        assert_called_with cache_helper, :output_buffer=, [output_buffer.class.new(output_buffer)] do
+          assert_nothing_raised do
+            cache_helper.send :fragment_for, 'Test fragment name', 'Test fragment', &Proc.new{ nil }
+          end
+        end
+      end
+    end
+  end
+
+  def test_safe_buffer
+    output_buffer = ActiveSupport::SafeBuffer.new
+    controller = MockController.new
+    cache_helper = Class.new do
+      def self.controller; end;
+      def self.output_buffer; end;
+      def self.output_buffer=; end;
+    end
+    cache_helper.extend(ActionView::Helpers::CacheHelper)
+
+    cache_helper.stub :controller, controller do
+      cache_helper.stub :output_buffer, output_buffer do
+        assert_called_with cache_helper, :output_buffer=, [output_buffer.class.new(output_buffer)] do
+          assert_nothing_raised do
+            cache_helper.send :fragment_for, 'Test fragment name', 'Test fragment', &Proc.new{ nil }
+          end
+        end
+      end
+    end
+  end
+end
+
+class ViewCacheDependencyTest < BaseCachingTest
+  class NoDependenciesMailer < ActionMailer::Base
+  end
+  class HasDependenciesMailer < ActionMailer::Base
+    view_cache_dependency { "trombone" }
+    view_cache_dependency { "flute" }
+  end
+
+  def test_view_cache_dependencies_are_empty_by_default
+    assert NoDependenciesMailer.new.view_cache_dependencies.empty?
+  end
+
+  def test_view_cache_dependencies_are_listed_in_declaration_order
+    assert_equal %w(trombone flute), HasDependenciesMailer.new.view_cache_dependencies
+  end
+end
diff --git a/actionmailer/test/fixtures/caching_mailer/_partial.html.erb b/actionmailer/test/fixtures/caching_mailer/_partial.html.erb
new file mode 100644
index 0000000000..8e965f52b4
--- /dev/null
+++ b/actionmailer/test/fixtures/caching_mailer/_partial.html.erb
@@ -0,0 +1,3 @@
+<% cache :caching do %>
+  Old fragment caching in a partial
+<% end %>
diff --git a/actionmailer/test/fixtures/caching_mailer/fragment_cache.html.erb b/actionmailer/test/fixtures/caching_mailer/fragment_cache.html.erb
new file mode 100644
index 0000000000..90189627da
--- /dev/null
+++ b/actionmailer/test/fixtures/caching_mailer/fragment_cache.html.erb
@@ -0,0 +1,3 @@
+<% cache :caching do %>
+"Welcome"
+<% end %>
diff --git a/actionmailer/test/fixtures/caching_mailer/fragment_cache_in_partials.html.erb b/actionmailer/test/fixtures/caching_mailer/fragment_cache_in_partials.html.erb
new file mode 100644
index 0000000000..2957d083e8
--- /dev/null
+++ b/actionmailer/test/fixtures/caching_mailer/fragment_cache_in_partials.html.erb
@@ -0,0 +1 @@
+<%= render "partial" %>
diff --git a/actionmailer/test/fixtures/caching_mailer/skip_fragment_cache_digesting.html.erb b/actionmailer/test/fixtures/caching_mailer/skip_fragment_cache_digesting.html.erb
new file mode 100644
index 0000000000..0d52429a81
--- /dev/null
+++ b/actionmailer/test/fixtures/caching_mailer/skip_fragment_cache_digesting.html.erb
@@ -0,0 +1,3 @@
+<%= cache :no_digest, skip_digest: true do %>
+  No Digest
+<% end %>
diff --git a/actionmailer/test/mailers/caching_mailer.rb b/actionmailer/test/mailers/caching_mailer.rb
new file mode 100644
index 0000000000..345d267a36
--- /dev/null
+++ b/actionmailer/test/mailers/caching_mailer.rb
@@ -0,0 +1,15 @@
+class CachingMailer < ActionMailer::Base
+  self.mailer_name = "caching_mailer"
+
+  def fragment_cache
+    mail(subject: "welcome", template_name: "fragment_cache")
+  end
+
+  def fragment_cache_in_partials
+    mail(subject: "welcome", template_name: "fragment_cache_in_partials")
+  end
+
+  def skip_fragment_cache_digesting
+    mail(subject: "welcome", template_name: "skip_fragment_cache_digesting")
+  end
+end