From 3077cdf921fed35c1e743db5911d7e4b589a684e Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Wed, 13 Feb 2019 15:35:20 -0800
Subject: [PATCH 1/5] rename push / pop function

---
 actionview/lib/action_view/base.rb                     | 2 +-
 actionview/lib/action_view/helpers/rendering_helper.rb | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/actionview/lib/action_view/base.rb b/actionview/lib/action_view/base.rb
index 556a5ee502..be2a662adc 100644
--- a/actionview/lib/action_view/base.rb
+++ b/actionview/lib/action_view/base.rb
@@ -286,7 +286,7 @@ module ActionView #:nodoc:
       self.class
     end
 
-    def in_context(options, locals)
+    def in_rendering_context(options)
       old_view_renderer  = @view_renderer
       old_lookup_context = @lookup_context
 
diff --git a/actionview/lib/action_view/helpers/rendering_helper.rb b/actionview/lib/action_view/helpers/rendering_helper.rb
index 7323963c72..7ead691113 100644
--- a/actionview/lib/action_view/helpers/rendering_helper.rb
+++ b/actionview/lib/action_view/helpers/rendering_helper.rb
@@ -27,7 +27,7 @@ module ActionView
       def render(options = {}, locals = {}, &block)
         case options
         when Hash
-          in_context(options, locals) do |renderer|
+          in_rendering_context(options) do |renderer|
             if block_given?
               view_renderer.render_partial(self, options.merge(partial: options[:layout]), &block)
             else

From 4f77982e213e31d9c6e7195c7db86429b8092744 Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Wed, 13 Feb 2019 17:08:42 -0800
Subject: [PATCH 2/5] Add a test that writes to the collection cache

---
 actionview/test/template/render_test.rb | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/actionview/test/template/render_test.rb b/actionview/test/template/render_test.rb
index 5068e00c7d..8d28f71585 100644
--- a/actionview/test/template/render_test.rb
+++ b/actionview/test/template/render_test.rb
@@ -743,10 +743,17 @@ class CachedCollectionViewRenderTest < ActiveSupport::TestCase
   end
 
   teardown do
-    GC.start
     I18n.reload!
   end
 
+  test "template body written to cache" do
+    customer = Customer.new("david", 1)
+    key = cache_key(customer, "test/_customer")
+    assert_nil ActionView::PartialRenderer.collection_cache.read(key)
+    @view.render(partial: "test/customer", collection: [customer], cached: true)
+    assert_equal "Hello: david", ActionView::PartialRenderer.collection_cache.read(key)
+  end
+
   test "collection caching does not cache by default" do
     customer = Customer.new("david", 1)
     key = cache_key(customer, "test/_customer")

From d0733ba8c0528aa4bc6e890e189afaac62ebe58f Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Wed, 13 Feb 2019 17:17:48 -0800
Subject: [PATCH 3/5] Move inline rendering content-type test to a controller
 test

This commit is to remove direct access to the "rendered_format"
attribute on the lookup context.  "rendered_format" is an implementation
detail that we shouldn't test directly.
---
 actionview/test/actionpack/controller/render_test.rb | 11 +++++++++++
 actionview/test/template/render_test.rb              |  5 -----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/actionview/test/actionpack/controller/render_test.rb b/actionview/test/actionpack/controller/render_test.rb
index 727d3fbc1a..52c3c54d96 100644
--- a/actionview/test/actionpack/controller/render_test.rb
+++ b/actionview/test/actionpack/controller/render_test.rb
@@ -174,6 +174,10 @@ class TestController < ActionController::Base
     render inline: "<%= controller_name %>"
   end
 
+  def inline_rendered_format_without_format
+    render inline: "test"
+  end
+
   # :ported:
   def render_custom_code
     render plain: "hello world", status: 404
@@ -659,6 +663,7 @@ class RenderTest < ActionController::TestCase
     get :hello_world_from_rxml_using_action, to: "test#hello_world_from_rxml_using_action"
     get :hello_world_from_rxml_using_template, to: "test#hello_world_from_rxml_using_template"
     get :hello_world_with_layout_false, to: "test#hello_world_with_layout_false"
+    get :inline_rendered_format_without_format, to: "test#inline_rendered_format_without_format"
     get :layout_overriding_layout, to: "test#layout_overriding_layout"
     get :layout_test, to: "test#layout_test"
     get :layout_test_with_different_layout, to: "test#layout_test_with_different_layout"
@@ -1015,6 +1020,12 @@ class RenderTest < ActionController::TestCase
     assert_equal "<wrapper>\n<html>\n  <p>Hello </p>\n<p>This is grand!</p>\n</html>\n</wrapper>\n", @response.body
   end
 
+  def test_rendered_format_without_format
+    get :inline_rendered_format_without_format
+    assert_equal "test", @response.body
+    assert_equal "text/html", @response.content_type
+  end
+
   def test_partials_list
     get :partials_list
     assert_equal "goodbyeHello: davidHello: marygoodbye\n", @response.body
diff --git a/actionview/test/template/render_test.rb b/actionview/test/template/render_test.rb
index 8d28f71585..ee8a110b44 100644
--- a/actionview/test/template/render_test.rb
+++ b/actionview/test/template/render_test.rb
@@ -69,11 +69,6 @@ module RenderTestCases
     assert_match "<error>No Comment</error>", @view.render(template: "comments/empty", formats: [:xml])
   end
 
-  def test_rendered_format_without_format
-    @view.render(inline: "test")
-    assert_equal :html, @view.lookup_context.rendered_format
-  end
-
   def test_render_partial_implicitly_use_format_of_the_rendered_template
     @view.lookup_context.formats = [:json]
     assert_equal "Hello world", @view.render(template: "test/one", formats: [:html])

From 1bc0a59d6ee198fa535c04f32527a1d6228b647d Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Wed, 13 Feb 2019 17:59:21 -0800
Subject: [PATCH 4/5] Return rendered template information instead of just
 strings

This commit introduces "rendered template" and "rendered collection"
objects.  The template renderers can now return a more complex object
than just strings.  This allows the framework to get more information
about the templates that were rendered.  In this commit we use the
rendered template object to set the "rendered_format" on the lookup
context in the controller rather than all the way in the template renderer.
That means we don't need to check the "rendered_format" every time we
render a template, we just do it once after all templates have been
rendered.
---
 .../action_view/renderer/abstract_renderer.rb | 48 +++++++++++++++++++
 .../action_view/renderer/partial_renderer.rb  | 25 ++++------
 .../partial_renderer/collection_caching.rb    | 10 ++--
 .../lib/action_view/renderer/renderer.rb      | 20 ++++++--
 .../renderer/streaming_template_renderer.rb   |  2 +-
 .../action_view/renderer/template_renderer.rb |  9 ++--
 actionview/lib/action_view/rendering.rb       |  9 +++-
 7 files changed, 92 insertions(+), 31 deletions(-)

diff --git a/actionview/lib/action_view/renderer/abstract_renderer.rb b/actionview/lib/action_view/renderer/abstract_renderer.rb
index ae366ce54a..2a51f2ef99 100644
--- a/actionview/lib/action_view/renderer/abstract_renderer.rb
+++ b/actionview/lib/action_view/renderer/abstract_renderer.rb
@@ -27,6 +27,46 @@ module ActionView
       raise NotImplementedError
     end
 
+    class RenderedCollection # :nodoc:
+      attr_reader :rendered_templates
+
+      def initialize(rendered_templates, spacer)
+        @rendered_templates = rendered_templates
+        @spacer = spacer
+      end
+
+      def body
+        @rendered_templates.map(&:body).join(@spacer.body).html_safe
+      end
+
+      def format
+        rendered_templates.first.format
+      end
+
+      class EmptyCollection
+        def format; nil; end
+        def body; nil; end
+      end
+
+      EMPTY = EmptyCollection.new
+    end
+
+    class RenderedTemplate # :nodoc:
+      attr_reader :body, :layout, :template
+
+      def initialize(body, layout, template)
+        @body = body
+        @layout = layout
+        @template = template
+      end
+
+      def format
+        template.formats.first
+      end
+
+      EMPTY_SPACER = Struct.new(:body).new
+    end
+
     private
 
       def extract_details(options) # :doc:
@@ -49,5 +89,13 @@ module ActionView
 
         @lookup_context.formats = formats | @lookup_context.formats
       end
+
+      def build_rendered_template(content, layout, template)
+        RenderedTemplate.new content, layout, template
+      end
+
+      def build_rendered_collection(templates, spacer)
+        RenderedCollection.new(templates, spacer)
+      end
   end
 end
diff --git a/actionview/lib/action_view/renderer/partial_renderer.rb b/actionview/lib/action_view/renderer/partial_renderer.rb
index f8a6f13ae9..f4319b8528 100644
--- a/actionview/lib/action_view/renderer/partial_renderer.rb
+++ b/actionview/lib/action_view/renderer/partial_renderer.rb
@@ -314,14 +314,6 @@ module ActionView
         template = nil
       end
 
-      @lookup_context.rendered_format ||= begin
-        if template && template.formats.first
-          template.formats.first
-        else
-          formats.first
-        end
-      end
-
       if @collection
         render_collection(context, template)
       else
@@ -334,10 +326,13 @@ module ActionView
       def render_collection(view, template)
         identifier = (template && template.identifier) || @path
         instrument(:collection, identifier: identifier, count: @collection.size) do |payload|
-          return nil if @collection.blank?
+          return RenderedCollection::EMPTY if @collection.blank?
 
-          if @options.key?(:spacer_template)
-            spacer = find_template(@options[:spacer_template], @locals.keys).render(view, @locals)
+          spacer = if @options.key?(:spacer_template)
+            spacer_template = find_template(@options[:spacer_template], @locals.keys)
+            build_rendered_template(spacer_template.render(view, @locals), nil, spacer_template)
+          else
+            RenderedTemplate::EMPTY_SPACER
           end
 
           collection_body = if template
@@ -347,7 +342,7 @@ module ActionView
           else
             collection_without_template(view)
           end
-          collection_body.join(spacer).html_safe
+          build_rendered_collection(collection_body, spacer)
         end
       end
 
@@ -369,7 +364,7 @@ module ActionView
 
           content = layout.render(view, locals) { content } if layout
           payload[:cache_hit] = view.view_renderer.cache_hits[template.virtual_path]
-          content
+          build_rendered_template(content, layout, template)
         end
       end
 
@@ -460,7 +455,7 @@ module ActionView
           content = template.render(view, locals)
           content = layout.render(view, locals) { content } if layout
           partial_iteration.iterate!
-          content
+          build_rendered_template(content, layout, template)
         end
       end
 
@@ -482,7 +477,7 @@ module ActionView
           template = (cache[path] ||= find_template(path, keys + [as, counter, iteration]))
           content = template.render(view, locals)
           partial_iteration.iterate!
-          content
+          build_rendered_template(content, nil, template)
         end
       end
 
diff --git a/actionview/lib/action_view/renderer/partial_renderer/collection_caching.rb b/actionview/lib/action_view/renderer/partial_renderer/collection_caching.rb
index 9f1de5a397..401391290f 100644
--- a/actionview/lib/action_view/renderer/partial_renderer/collection_caching.rb
+++ b/actionview/lib/action_view/renderer/partial_renderer/collection_caching.rb
@@ -40,7 +40,7 @@ module ActionView
         rendered_partials = @collection.empty? ? [] : yield
 
         index = 0
-        fetch_or_cache_partial(cached_partials, order_by: keyed_collection.each_key) do
+        fetch_or_cache_partial(cached_partials, template, order_by: keyed_collection.each_key) do
           # This block is called once
           # for every cache miss while preserving order.
           rendered_partials[index].tap { index += 1 }
@@ -81,11 +81,13 @@ module ActionView
       #
       # If the partial is not already cached it will also be
       # written back to the underlying cache store.
-      def fetch_or_cache_partial(cached_partials, order_by:)
+      def fetch_or_cache_partial(cached_partials, template, order_by:)
         order_by.map do |cache_key|
-          cached_partials.fetch(cache_key) do
+          if content = cached_partials[cache_key]
+            build_rendered_template(content, nil, template)
+          else
             yield.tap do |rendered_partial|
-              collection_cache.write(cache_key, rendered_partial)
+              collection_cache.write(cache_key, rendered_partial.body)
             end
           end
         end
diff --git a/actionview/lib/action_view/renderer/renderer.rb b/actionview/lib/action_view/renderer/renderer.rb
index 3f3a97529d..485eb1a5b4 100644
--- a/actionview/lib/action_view/renderer/renderer.rb
+++ b/actionview/lib/action_view/renderer/renderer.rb
@@ -19,10 +19,14 @@ module ActionView
 
     # Main render entry point shared by Action View and Action Controller.
     def render(context, options)
+      render_to_object(context, options).body
+    end
+
+    def render_to_object(context, options) # :nodoc:
       if options.key?(:partial)
-        render_partial(context, options)
+        render_partial_to_object(context, options)
       else
-        render_template(context, options)
+        render_template_to_object(context, options)
       end
     end
 
@@ -41,16 +45,24 @@ module ActionView
 
     # Direct access to template rendering.
     def render_template(context, options) #:nodoc:
-      TemplateRenderer.new(@lookup_context).render(context, options)
+      render_template_to_object(context, options).body
     end
 
     # Direct access to partial rendering.
     def render_partial(context, options, &block) #:nodoc:
-      PartialRenderer.new(@lookup_context).render(context, options, block)
+      render_partial_to_object(context, options, &block).body
     end
 
     def cache_hits # :nodoc:
       @cache_hits ||= {}
     end
+
+    def render_template_to_object(context, options) #:nodoc:
+      TemplateRenderer.new(@lookup_context).render(context, options)
+    end
+
+    def render_partial_to_object(context, options, &block) #:nodoc:
+      PartialRenderer.new(@lookup_context).render(context, options, block)
+    end
   end
 end
diff --git a/actionview/lib/action_view/renderer/streaming_template_renderer.rb b/actionview/lib/action_view/renderer/streaming_template_renderer.rb
index f414620923..279ef3c680 100644
--- a/actionview/lib/action_view/renderer/streaming_template_renderer.rb
+++ b/actionview/lib/action_view/renderer/streaming_template_renderer.rb
@@ -44,7 +44,7 @@ module ActionView
     # object that responds to each. This object is initialized with a block
     # that knows how to render the template.
     def render_template(view, template, layout_name = nil, locals = {}) #:nodoc:
-      return [super] unless layout_name && template.supports_streaming?
+      return [super.body] unless layout_name && template.supports_streaming?
 
       locals ||= {}
       layout   = layout_name && find_layout(layout_name, locals.keys, [formats.first])
diff --git a/actionview/lib/action_view/renderer/template_renderer.rb b/actionview/lib/action_view/renderer/template_renderer.rb
index c36baeffcd..7052fe0961 100644
--- a/actionview/lib/action_view/renderer/template_renderer.rb
+++ b/actionview/lib/action_view/renderer/template_renderer.rb
@@ -10,8 +10,6 @@ module ActionView
 
       prepend_formats(template.formats)
 
-      @lookup_context.rendered_format ||= (template.formats.first || formats.first)
-
       render_template(context, template, options[:layout], options[:locals] || {})
     end
 
@@ -46,23 +44,24 @@ module ActionView
       # Renders the given template. A string representing the layout can be
       # supplied as well.
       def render_template(view, template, layout_name, locals)
-        render_with_layout(view, layout_name, locals) do |layout|
+        render_with_layout(view, layout_name, template, locals) do |layout|
           instrument(:template, identifier: template.identifier, layout: layout.try(:virtual_path)) do
             template.render(view, locals) { |*name| view._layout_for(*name) }
           end
         end
       end
 
-      def render_with_layout(view, path, locals)
+      def render_with_layout(view, path, template, locals)
         layout  = path && find_layout(path, locals.keys, [formats.first])
         content = yield(layout)
 
-        if layout
+        body = if layout
           view.view_flow.set(:layout, content)
           layout.render(view, locals) { |*name| view._layout_for(*name) }
         else
           content
         end
+        build_rendered_template(body, layout, template)
       end
 
       # This is the method which actually finds the layout using details in the lookup
diff --git a/actionview/lib/action_view/rendering.rb b/actionview/lib/action_view/rendering.rb
index b798e80b04..699ccb0ca8 100644
--- a/actionview/lib/action_view/rendering.rb
+++ b/actionview/lib/action_view/rendering.rb
@@ -109,10 +109,15 @@ module ActionView
         context = view_context
 
         context.assign assigns if assigns
-        lookup_context.rendered_format = nil if options[:formats]
         lookup_context.variants = variant if variant
 
-        context.view_renderer.render(context, options)
+        rendered_template = context.in_rendering_context(options) do |renderer|
+          renderer.render_to_object(context, options)
+        end
+
+        lookup_context.rendered_format = rendered_template.format || lookup_context.formats.first
+
+        rendered_template.body
       end
 
       # Assign the rendered format to look up context.

From 3f84a814aa1d934fc0e577ff1d69f0e814b9d1c2 Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Tue, 19 Feb 2019 14:57:29 -0800
Subject: [PATCH 5/5] Fix up style

---
 actionview/lib/action_view/renderer/abstract_renderer.rb  | 4 ++--
 actionview/lib/action_view/renderer/partial_renderer.rb   | 8 ++++----
 .../renderer/partial_renderer/collection_caching.rb       | 2 +-
 actionview/lib/action_view/renderer/template_renderer.rb  | 2 +-
 4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/actionview/lib/action_view/renderer/abstract_renderer.rb b/actionview/lib/action_view/renderer/abstract_renderer.rb
index 2a51f2ef99..200dc3e10e 100644
--- a/actionview/lib/action_view/renderer/abstract_renderer.rb
+++ b/actionview/lib/action_view/renderer/abstract_renderer.rb
@@ -90,12 +90,12 @@ module ActionView
         @lookup_context.formats = formats | @lookup_context.formats
       end
 
-      def build_rendered_template(content, layout, template)
+      def build_rendered_template(content, template, layout = nil)
         RenderedTemplate.new content, layout, template
       end
 
       def build_rendered_collection(templates, spacer)
-        RenderedCollection.new(templates, spacer)
+        RenderedCollection.new templates, spacer
       end
   end
 end
diff --git a/actionview/lib/action_view/renderer/partial_renderer.rb b/actionview/lib/action_view/renderer/partial_renderer.rb
index f4319b8528..4ae6f635ae 100644
--- a/actionview/lib/action_view/renderer/partial_renderer.rb
+++ b/actionview/lib/action_view/renderer/partial_renderer.rb
@@ -330,7 +330,7 @@ module ActionView
 
           spacer = if @options.key?(:spacer_template)
             spacer_template = find_template(@options[:spacer_template], @locals.keys)
-            build_rendered_template(spacer_template.render(view, @locals), nil, spacer_template)
+            build_rendered_template(spacer_template.render(view, @locals), spacer_template)
           else
             RenderedTemplate::EMPTY_SPACER
           end
@@ -364,7 +364,7 @@ module ActionView
 
           content = layout.render(view, locals) { content } if layout
           payload[:cache_hit] = view.view_renderer.cache_hits[template.virtual_path]
-          build_rendered_template(content, layout, template)
+          build_rendered_template(content, template, layout)
         end
       end
 
@@ -455,7 +455,7 @@ module ActionView
           content = template.render(view, locals)
           content = layout.render(view, locals) { content } if layout
           partial_iteration.iterate!
-          build_rendered_template(content, layout, template)
+          build_rendered_template(content, template, layout)
         end
       end
 
@@ -477,7 +477,7 @@ module ActionView
           template = (cache[path] ||= find_template(path, keys + [as, counter, iteration]))
           content = template.render(view, locals)
           partial_iteration.iterate!
-          build_rendered_template(content, nil, template)
+          build_rendered_template(content, template)
         end
       end
 
diff --git a/actionview/lib/action_view/renderer/partial_renderer/collection_caching.rb b/actionview/lib/action_view/renderer/partial_renderer/collection_caching.rb
index 401391290f..ed59033e27 100644
--- a/actionview/lib/action_view/renderer/partial_renderer/collection_caching.rb
+++ b/actionview/lib/action_view/renderer/partial_renderer/collection_caching.rb
@@ -84,7 +84,7 @@ module ActionView
       def fetch_or_cache_partial(cached_partials, template, order_by:)
         order_by.map do |cache_key|
           if content = cached_partials[cache_key]
-            build_rendered_template(content, nil, template)
+            build_rendered_template(content, template)
           else
             yield.tap do |rendered_partial|
               collection_cache.write(cache_key, rendered_partial.body)
diff --git a/actionview/lib/action_view/renderer/template_renderer.rb b/actionview/lib/action_view/renderer/template_renderer.rb
index 7052fe0961..c17d6182e8 100644
--- a/actionview/lib/action_view/renderer/template_renderer.rb
+++ b/actionview/lib/action_view/renderer/template_renderer.rb
@@ -61,7 +61,7 @@ module ActionView
         else
           content
         end
-        build_rendered_template(body, layout, template)
+        build_rendered_template(body, template, layout)
       end
 
       # This is the method which actually finds the layout using details in the lookup