From c0b99c980ce21bb920792ce1ac65dc5614b4a9a6 Mon Sep 17 00:00:00 2001
From: Mauro George <maurogot@gmail.com>
Date: Sat, 29 Aug 2015 12:37:24 -0300
Subject: [PATCH 1/9] Bring back assert_serializer for controller testing

The `assert_serializer` test helper was added in 0.9.0.apha1[1],
and was not included in 0.10.

This patch brings back the `assert_serializer` test helper. This is the last
revision[2] that has the helper. The original helper was used as base.

[1]: https://github.com/rails-api/active_model_serializers/pull/596
[2]: https://github.com/rails-api/active_model_serializers/tree/610aeb2e9297fa31b8d561f0be9a4597f0258f8c

- Create the AssertSerializer

- Use the Test namespace

- Make the tests pass on the Rails master
  - Rails 5 does not include `assert_template` but we need this on the tests of
the helper.
  - This add the `rails-controller-testing` to keep support on `assert_template`.

- Only load test helpers in the test environment
---
 CHANGELOG.md                                  |   1 +
 Gemfile                                       |   1 +
 docs/README.md                                |   1 +
 docs/howto/test.md                            |  29 +++++
 lib/active_model/serializer/railtie.rb        |   4 +
 lib/active_model_serializers.rb               |   1 +
 lib/active_model_serializers/test.rb          |   5 +
 .../test/serializer.rb                        | 122 ++++++++++++++++++
 .../test/serializer_test.rb                   |  73 +++++++++++
 test/fixtures/template.html.erb               |   1 +
 10 files changed, 238 insertions(+)
 create mode 100644 docs/howto/test.md
 create mode 100644 lib/active_model_serializers/test.rb
 create mode 100644 lib/active_model_serializers/test/serializer.rb
 create mode 100644 test/active_model_serializers/test/serializer_test.rb
 create mode 100644 test/fixtures/template.html.erb

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a89c9e05..8ec8a389 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -45,6 +45,7 @@ Features:
     CollectionSerializer for clarity, add ActiveModelSerializers.config.collection_serializer (@bf4)
 - [#1295](https://github.com/rails-api/active_model_serializers/pull/1295) Add config `serializer_lookup_enabled` that,
   when disabled, requires serializers to explicitly specified. (@trek)
+- [#1099](https://github.com/rails-api/active_model_serializers/pull/1099) Adds `assert_serializer` test helper (@maurogeorge)
 
 Fixes:
 - [#1239](https://github.com/rails-api/active_model_serializers/pull/1239) Fix duplicates in JSON API compound documents (@beauby)
diff --git a/Gemfile b/Gemfile
index 9a386356..659f82e0 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,6 +12,7 @@ version = ENV['RAILS_VERSION'] || '4.2'
 if version == 'master'
   gem 'rack', github: 'rack/rack'
   gem 'arel', github: 'rails/arel'
+  gem 'rails-controller-testing', github: 'rails/rails-controller-testing'
   git 'https://github.com/rails/rails.git' do
     gem 'railties'
     gem 'activesupport'
diff --git a/docs/README.md b/docs/README.md
index a20c086e..7f0a8ac0 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -22,6 +22,7 @@ This is the documentation of ActiveModelSerializers, it's focused on the **0.10.
 - [How to add root key](howto/add_root_key.md)
 - [How to add pagination links](howto/add_pagination_links.md)
 - [Using ActiveModelSerializers Outside Of Controllers](howto/outside_controller_use.md)
+- [Testing ActiveModelSerializers](howto/test.md)
 
 ## Integrations
 
diff --git a/docs/howto/test.md b/docs/howto/test.md
new file mode 100644
index 00000000..67cbef1c
--- /dev/null
+++ b/docs/howto/test.md
@@ -0,0 +1,29 @@
+# How to test
+
+## Test helpers
+
+ActiveModelSerializers provides a `assert_serializer` method to be used on your controller tests to
+assert that a specific serializer was used.
+
+```ruby
+class PostsControllerTest < ActionController::TestCase
+  test "should render post serializer" do
+    get :index
+    assert_serializer "PostSerializer"
+    #  # return a custom error message
+    #  assert_serializer "PostSerializer", "PostSerializer not rendered"
+    #
+    #  # assert that the instance of PostSerializer was rendered
+    #  assert_serializer PostSerializer
+    #
+    #  # assert that the "PostSerializer" serializer was rendered
+    #  assert_serializer :post_serializer
+    #
+    #  # assert that the rendered serializer starts with "Post"
+    #  assert_serializer %r{\APost.+\Z}
+    #
+    #  # assert that no serializer was rendered
+    #  assert_serializer nil
+  end
+end
+```
diff --git a/lib/active_model/serializer/railtie.rb b/lib/active_model/serializer/railtie.rb
index 18bb513c..e0af1cad 100644
--- a/lib/active_model/serializer/railtie.rb
+++ b/lib/active_model/serializer/railtie.rb
@@ -19,5 +19,9 @@ module ActiveModel
       app.load_generators
       require 'generators/serializer/resource_override'
     end
+
+    if Rails.env.test?
+      ActionController::TestCase.send(:include, ActiveModelSerializers::Test::Serializer)
+    end
   end
 end
diff --git a/lib/active_model_serializers.rb b/lib/active_model_serializers.rb
index b955d7a0..af216516 100644
--- a/lib/active_model_serializers.rb
+++ b/lib/active_model_serializers.rb
@@ -14,6 +14,7 @@ module ActiveModelSerializers
   autoload :Callbacks
   autoload :Deserialization
   autoload :Logging
+  autoload :Test
 end
 
 require 'active_model/serializer'
diff --git a/lib/active_model_serializers/test.rb b/lib/active_model_serializers/test.rb
new file mode 100644
index 00000000..77f0b702
--- /dev/null
+++ b/lib/active_model_serializers/test.rb
@@ -0,0 +1,5 @@
+module ActiveModelSerializers
+  module Test
+    autoload :Serializer, 'active_model_serializers/test/serializer'
+  end
+end
diff --git a/lib/active_model_serializers/test/serializer.rb b/lib/active_model_serializers/test/serializer.rb
new file mode 100644
index 00000000..8e8c9549
--- /dev/null
+++ b/lib/active_model_serializers/test/serializer.rb
@@ -0,0 +1,122 @@
+module ActiveModelSerializers
+  module Test
+    module Serializer
+      extend ActiveSupport::Concern
+
+      included do
+        setup :setup_serialization_subscriptions
+      end
+
+      # Asserts that the request was rendered with the appropriate serializers.
+      #
+      #  # assert that the "PostSerializer" serializer was rendered
+      #  assert_serializer "PostSerializer"
+      #
+      #  # return a custom error message
+      #  assert_serializer "PostSerializer", "PostSerializer not rendered"
+      #
+      #  # assert that the instance of PostSerializer was rendered
+      #  assert_serializer PostSerializer
+      #
+      #  # assert that the "PostSerializer" serializer was rendered
+      #  assert_serializer :post_serializer
+      #
+      #  # assert that the rendered serializer starts with "Post"
+      #  assert_serializer %r{\APost.+\Z}
+      #
+      #  # assert that no serializer was rendered
+      #  assert_serializer nil
+      #
+      def assert_serializer(expectation, message = nil)
+        @assert_serializer.expectation = expectation
+        @assert_serializer.message = message
+        @assert_serializer.response = response
+        assert(@assert_serializer.matches?, @assert_serializer.message)
+      end
+
+      class AssertSerializer
+        attr_reader :serializers, :message
+        attr_accessor :response, :expectation
+
+        def initialize
+          @serializers = []
+        end
+
+        def message=(message)
+          @message = message || "expecting <#{expectation.inspect}> but rendering with <#{serializers}>"
+        end
+
+        def matches?
+          # Force body to be read in case the template is being streamed.
+          response.body
+
+          case expectation
+          when a_serializer?
+            matches_class?
+          when Symbol
+            matches_symbol?
+          when String
+            matches_string?
+          when Regexp
+            matches_regexp?
+          when NilClass
+            matches_nil?
+          else
+            fail ArgumentError, 'assert_serializer only accepts a String, Symbol, Regexp, ActiveModel::Serializer, or nil'
+          end
+        end
+
+        def subscribe
+          ActiveSupport::Notifications.subscribe(event_name) do |_name, _start, _finish, _id, payload|
+            serializer = payload[:serializer].name
+            serializers << serializer
+          end
+        end
+
+        def unsubscribe
+          ActiveSupport::Notifications.unsubscribe(event_name)
+        end
+
+        private
+
+        def matches_class?
+          serializers.include?(expectation.name)
+        end
+
+        def matches_symbol?
+          camelize_expectation = expectation.to_s.camelize
+          serializers.include?(camelize_expectation)
+        end
+
+        def matches_string?
+          !expectation.empty? && serializers.include?(expectation)
+        end
+
+        def matches_regexp?
+          serializers.any? do |serializer|
+            serializer.match(expectation)
+          end
+        end
+
+        def matches_nil?
+          serializers.blank?
+        end
+
+        def a_serializer?
+          ->(exp) { exp.is_a?(Class) && exp < ActiveModel::Serializer }
+        end
+
+        def event_name
+          'render.active_model_serializers'
+        end
+      end
+
+      private
+
+      def setup_serialization_subscriptions
+        @assert_serializer = AssertSerializer.new
+        @assert_serializer.subscribe
+      end
+    end
+  end
+end
diff --git a/test/active_model_serializers/test/serializer_test.rb b/test/active_model_serializers/test/serializer_test.rb
new file mode 100644
index 00000000..3a5f0e99
--- /dev/null
+++ b/test/active_model_serializers/test/serializer_test.rb
@@ -0,0 +1,73 @@
+require 'test_helper'
+require 'rails-controller-testing' if Rails::VERSION::MAJOR >= 5
+
+module ActiveModelSerializers
+  module Test
+    class SerializerTest < ActionController::TestCase
+      include ActiveModelSerializers::Test::Serializer
+
+      class MyController < ActionController::Base
+        def render_using_serializer
+          render json: Profile.new(name: 'Name 1', description: 'Description 1', comments: 'Comments 1')
+        end
+
+        def render_text
+          render text: 'ok'
+        end
+
+        def render_template
+          prepend_view_path './test/fixtures'
+          render template: 'template'
+        end
+      end
+
+      tests MyController
+
+      def test_supports_specifying_serializers_with_a_serializer_class
+        get :render_using_serializer
+        assert_serializer ProfileSerializer
+      end
+
+      def test_supports_specifying_serializers_with_a_regexp
+        get :render_using_serializer
+        assert_serializer(/\AProfile.+\Z/)
+      end
+
+      def test_supports_specifying_serializers_with_a_string
+        get :render_using_serializer
+        assert_serializer 'ProfileSerializer'
+      end
+
+      def test_supports_specifying_serializers_with_a_symbol
+        get :render_using_serializer
+        assert_serializer :profile_serializer
+      end
+
+      def test_supports_specifying_serializers_with_a_nil
+        get :render_text
+        assert_serializer nil
+      end
+
+      def test_raises_descriptive_error_message_when_serializer_was_not_rendered
+        get :render_using_serializer
+        e = assert_raise ActiveSupport::TestCase::Assertion do
+          assert_serializer 'PostSerializer'
+        end
+        assert_match 'expecting <"PostSerializer"> but rendering with <["ProfileSerializer"]>', e.message
+      end
+
+      def test_raises_argument_error_when_asserting_with_invalid_object
+        get :render_using_serializer
+        e = assert_raise ArgumentError do
+          assert_serializer Hash
+        end
+        assert_match 'assert_serializer only accepts a String, Symbol, Regexp, ActiveModel::Serializer, or nil', e.message
+      end
+
+      def test_does_not_overwrite_notification_subscriptions
+        get :render_template
+        assert_template 'template'
+      end
+    end
+  end
+end
diff --git a/test/fixtures/template.html.erb b/test/fixtures/template.html.erb
new file mode 100644
index 00000000..1f87be87
--- /dev/null
+++ b/test/fixtures/template.html.erb
@@ -0,0 +1 @@
+<p>Hello.</p>

From 37a6d2b2454d39d3dd2550c45cf1f40f53df8fa2 Mon Sep 17 00:00:00 2001
From: Benjamin Fleischer <github@benjaminfleischer.com>
Date: Tue, 22 Dec 2015 22:42:15 -0600
Subject: [PATCH 2/9] Be consisent in usage of ActiveSupport::Autoload

---
 lib/active_model_serializers/test.rb | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/active_model_serializers/test.rb b/lib/active_model_serializers/test.rb
index 77f0b702..4f539a44 100644
--- a/lib/active_model_serializers/test.rb
+++ b/lib/active_model_serializers/test.rb
@@ -1,5 +1,6 @@
 module ActiveModelSerializers
   module Test
-    autoload :Serializer, 'active_model_serializers/test/serializer'
+    extend ActiveSupport::Autoload
+    autoload :Serializer
   end
 end

From ef09c9043f46807c61d1f82d2cf1c717cc046e43 Mon Sep 17 00:00:00 2001
From: Benjamin Fleischer <github@benjaminfleischer.com>
Date: Tue, 22 Dec 2015 22:43:06 -0600
Subject: [PATCH 3/9] Small perf, readability refactor to Test::Serializer

---
 .../test/serializer.rb                        | 28 ++++++++-----------
 1 file changed, 12 insertions(+), 16 deletions(-)

diff --git a/lib/active_model_serializers/test/serializer.rb b/lib/active_model_serializers/test/serializer.rb
index 8e8c9549..a122d31d 100644
--- a/lib/active_model_serializers/test/serializer.rb
+++ b/lib/active_model_serializers/test/serializer.rb
@@ -1,3 +1,4 @@
+require 'set'
 module ActiveModelSerializers
   module Test
     module Serializer
@@ -35,15 +36,16 @@ module ActiveModelSerializers
       end
 
       class AssertSerializer
+        EVENT_NAME = 'render.active_model_serializers'
         attr_reader :serializers, :message
         attr_accessor :response, :expectation
 
         def initialize
-          @serializers = []
+          @serializers = Set.new
         end
 
         def message=(message)
-          @message = message || "expecting <#{expectation.inspect}> but rendering with <#{serializers}>"
+          @message = message || "expecting <#{expectation.inspect}> but rendering with <#{serializers.to_a}>"
         end
 
         def matches?
@@ -51,18 +53,12 @@ module ActiveModelSerializers
           response.body
 
           case expectation
-          when a_serializer?
-            matches_class?
-          when Symbol
-            matches_symbol?
-          when String
-            matches_string?
-          when Regexp
-            matches_regexp?
-          when NilClass
-            matches_nil?
-          else
-            fail ArgumentError, 'assert_serializer only accepts a String, Symbol, Regexp, ActiveModel::Serializer, or nil'
+          when a_serializer? then matches_class?
+          when Symbol        then matches_symbol?
+          when String        then matches_string?
+          when Regexp        then matches_regexp?
+          when NilClass      then matches_nil?
+          else fail ArgumentError, 'assert_serializer only accepts a String, Symbol, Regexp, ActiveModel::Serializer, or nil'
           end
         end
 
@@ -99,7 +95,7 @@ module ActiveModelSerializers
         end
 
         def matches_nil?
-          serializers.blank?
+          serializers.empty?
         end
 
         def a_serializer?
@@ -107,7 +103,7 @@ module ActiveModelSerializers
         end
 
         def event_name
-          'render.active_model_serializers'
+          EVENT_NAME
         end
       end
 

From f59431439d1bf2b389f3869fb3117d4d9b45e6fc Mon Sep 17 00:00:00 2001
From: Benjamin Fleischer <github@benjaminfleischer.com>
Date: Tue, 22 Dec 2015 22:49:42 -0600
Subject: [PATCH 4/9] Remove unused/unusable unsubscribe since we don't want to
 unsubscribe

In 0.9 (which this implementation is based on), the instrumentation
was `!serialize.active_model_serializers`.

https://github.com/rails-api/active_model_serializers/pull/596/

The '!' in the event name meant the event wasn't meant for
production.

https://github.com/rails/rails/pull/10446/files#r4075679

Since we intend the event for production and have a log subscriber,
if we unsubscribe from `render.active_model_serializers`, we'll
break other tests that are relying on that event being subscribed.
---
 lib/active_model_serializers/test/serializer.rb | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/lib/active_model_serializers/test/serializer.rb b/lib/active_model_serializers/test/serializer.rb
index a122d31d..5e1b826b 100644
--- a/lib/active_model_serializers/test/serializer.rb
+++ b/lib/active_model_serializers/test/serializer.rb
@@ -69,10 +69,6 @@ module ActiveModelSerializers
           end
         end
 
-        def unsubscribe
-          ActiveSupport::Notifications.unsubscribe(event_name)
-        end
-
         private
 
         def matches_class?

From a43cff4ae3012874d6bb721fad46150dd2d30d66 Mon Sep 17 00:00:00 2001
From: Benjamin Fleischer <github@benjaminfleischer.com>
Date: Tue, 22 Dec 2015 22:59:04 -0600
Subject: [PATCH 5/9] Remove `assert_template` from Test::SerializerTest

Rails 5 removed this assertion after considering it not
a good testing practice. https://github.com/rails/rails/issues/18950

Rather that add a gem to our Rails 5 matrix to support it,
the assertion is made that the template is rendering using
active support notifications.

Also, to clarify that the action 'render_template' is unrelated to the
event name '!render_template.action_view', I renamed the actions
so that would not look like event names.
---
 Gemfile                                       |  1 -
 .../test/serializer_test.rb                   | 29 ++++++++++++++-----
 2 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/Gemfile b/Gemfile
index 659f82e0..9a386356 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,7 +12,6 @@ version = ENV['RAILS_VERSION'] || '4.2'
 if version == 'master'
   gem 'rack', github: 'rack/rack'
   gem 'arel', github: 'rails/arel'
-  gem 'rails-controller-testing', github: 'rails/rails-controller-testing'
   git 'https://github.com/rails/rails.git' do
     gem 'railties'
     gem 'activesupport'
diff --git a/test/active_model_serializers/test/serializer_test.rb b/test/active_model_serializers/test/serializer_test.rb
index 3a5f0e99..c6c10b71 100644
--- a/test/active_model_serializers/test/serializer_test.rb
+++ b/test/active_model_serializers/test/serializer_test.rb
@@ -1,5 +1,4 @@
 require 'test_helper'
-require 'rails-controller-testing' if Rails::VERSION::MAJOR >= 5
 
 module ActiveModelSerializers
   module Test
@@ -7,17 +6,19 @@ module ActiveModelSerializers
       include ActiveModelSerializers::Test::Serializer
 
       class MyController < ActionController::Base
+        TEMPLATE_NAME = 'template'
         def render_using_serializer
           render json: Profile.new(name: 'Name 1', description: 'Description 1', comments: 'Comments 1')
         end
 
-        def render_text
-          render text: 'ok'
+        # For Rails4.0
+        def render_some_text
+          Rails.version > '4.1' ? render(plain: 'ok') : render(text: 'ok')
         end
 
-        def render_template
+        def render_a_template
           prepend_view_path './test/fixtures'
-          render template: 'template'
+          render template: TEMPLATE_NAME
         end
       end
 
@@ -44,7 +45,7 @@ module ActiveModelSerializers
       end
 
       def test_supports_specifying_serializers_with_a_nil
-        get :render_text
+        get :render_some_text
         assert_serializer nil
       end
 
@@ -65,8 +66,20 @@ module ActiveModelSerializers
       end
 
       def test_does_not_overwrite_notification_subscriptions
-        get :render_template
-        assert_template 'template'
+        payloads = []
+        event_name = '!render_template.action_view'
+        ActiveSupport::Notifications.subscribe(event_name) do |_name, _start, _finish, _id, payload|
+          payloads << payload
+        end
+
+        get :render_a_template
+
+        assert_equal 1, payloads.size, 'Only expected one template rendering to be registered'
+        payload = payloads.first
+        assert_equal MyController::TEMPLATE_NAME, payload[:virtual_path]
+        assert_match %r{test/fixtures/#{MyController::TEMPLATE_NAME}.html.erb}, payload[:identifier]
+      ensure
+        ActiveSupport::Notifications.unsubscribe(event_name)
       end
     end
   end

From 28f314aef24cc0d5664800106da29fb3b1633e6b Mon Sep 17 00:00:00 2001
From: Benjamin Fleischer <github@benjaminfleischer.com>
Date: Tue, 22 Dec 2015 23:08:37 -0600
Subject: [PATCH 6/9] Surface logging event name for re-use

---
 lib/active_model_serializers/logging.rb         | 3 ++-
 lib/active_model_serializers/test/serializer.rb | 3 +--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/active_model_serializers/logging.rb b/lib/active_model_serializers/logging.rb
index bfe535c3..2a859c41 100644
--- a/lib/active_model_serializers/logging.rb
+++ b/lib/active_model_serializers/logging.rb
@@ -5,6 +5,7 @@
 #
 module ActiveModelSerializers
   module Logging
+    RENDER_EVENT = 'render.active_model_serializers'.freeze
     extend ActiveSupport::Concern
 
     included do
@@ -73,7 +74,7 @@ module ActiveModelSerializers
     end
 
     def notify_render(*)
-      event_name = 'render.active_model_serializers'.freeze
+      event_name = RENDER_EVENT
       ActiveSupport::Notifications.instrument(event_name, notify_render_payload) do
         yield
       end
diff --git a/lib/active_model_serializers/test/serializer.rb b/lib/active_model_serializers/test/serializer.rb
index 5e1b826b..16446989 100644
--- a/lib/active_model_serializers/test/serializer.rb
+++ b/lib/active_model_serializers/test/serializer.rb
@@ -36,7 +36,6 @@ module ActiveModelSerializers
       end
 
       class AssertSerializer
-        EVENT_NAME = 'render.active_model_serializers'
         attr_reader :serializers, :message
         attr_accessor :response, :expectation
 
@@ -99,7 +98,7 @@ module ActiveModelSerializers
         end
 
         def event_name
-          EVENT_NAME
+          ::ActiveModelSerializers::Logging::RENDER_EVENT
         end
       end
 

From e60937bc2f0961b6b97432aac2f1d30b6409ad3f Mon Sep 17 00:00:00 2001
From: Benjamin Fleischer <github@benjaminfleischer.com>
Date: Tue, 22 Dec 2015 23:10:29 -0600
Subject: [PATCH 7/9] Remove duplicate documentation

---
 docs/howto/test.md | 17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/docs/howto/test.md b/docs/howto/test.md
index 67cbef1c..70f59374 100644
--- a/docs/howto/test.md
+++ b/docs/howto/test.md
@@ -10,20 +10,9 @@ class PostsControllerTest < ActionController::TestCase
   test "should render post serializer" do
     get :index
     assert_serializer "PostSerializer"
-    #  # return a custom error message
-    #  assert_serializer "PostSerializer", "PostSerializer not rendered"
-    #
-    #  # assert that the instance of PostSerializer was rendered
-    #  assert_serializer PostSerializer
-    #
-    #  # assert that the "PostSerializer" serializer was rendered
-    #  assert_serializer :post_serializer
-    #
-    #  # assert that the rendered serializer starts with "Post"
-    #  assert_serializer %r{\APost.+\Z}
-    #
-    #  # assert that no serializer was rendered
-    #  assert_serializer nil
   end
 end
 ```
+
+See [ActiveModelSerializers::Test::Serializer](../../lib/active_model_serializers/test/serializer.rb)
+for more examples and documentation.

From 9779185d576e3ec98ef33b52b96b8674c057a915 Mon Sep 17 00:00:00 2001
From: Benjamin Fleischer <github@benjaminfleischer.com>
Date: Tue, 22 Dec 2015 23:26:26 -0600
Subject: [PATCH 8/9] Restore test-local subscriber teardown

This commit revises 0ce4ad35a12ffd858f6a5d7bbeb48fc1e2cfac92
`Remove unused/unusable unsubscribe since we don't want to unsubscribe`

Looking at Rails implementation of assert_template
which was likely the inspiration for assert_serializer:

https://github.com/rails/rails-controller-testing/blob/f756b33c138c593eabe37f6085f8bac477b99bfe/lib/rails/controller/testing/template_assertions.rb

Ref:

- https://github.com/rails-api/active_model_serializers/pull/596
- https://github.com/rails-api/active_model_serializers/pull/620
- https://github.com/rails-api/active_model_serializers/issues/616
---
 lib/active_model_serializers/test/serializer.rb | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/lib/active_model_serializers/test/serializer.rb b/lib/active_model_serializers/test/serializer.rb
index 16446989..dc812c55 100644
--- a/lib/active_model_serializers/test/serializer.rb
+++ b/lib/active_model_serializers/test/serializer.rb
@@ -6,6 +6,7 @@ module ActiveModelSerializers
 
       included do
         setup :setup_serialization_subscriptions
+        teardown :teardown_serialization_subscriptions
       end
 
       # Asserts that the request was rendered with the appropriate serializers.
@@ -41,6 +42,7 @@ module ActiveModelSerializers
 
         def initialize
           @serializers = Set.new
+          @_subscribers = []
         end
 
         def message=(message)
@@ -62,12 +64,18 @@ module ActiveModelSerializers
         end
 
         def subscribe
-          ActiveSupport::Notifications.subscribe(event_name) do |_name, _start, _finish, _id, payload|
+          @_subscribers << ActiveSupport::Notifications.subscribe(event_name) do |_name, _start, _finish, _id, payload|
             serializer = payload[:serializer].name
             serializers << serializer
           end
         end
 
+        def unsubscribe
+          @_subscribers.each do |subscriber|
+            ActiveSupport::Notifications.unsubscribe(subscriber)
+          end
+        end
+
         private
 
         def matches_class?
@@ -108,6 +116,10 @@ module ActiveModelSerializers
         @assert_serializer = AssertSerializer.new
         @assert_serializer.subscribe
       end
+
+      def teardown_serialization_subscriptions
+        @assert_serializer.unsubscribe
+      end
     end
   end
 end

From f5e2b991bf6c54ed2e860f6e101e46c2587858e5 Mon Sep 17 00:00:00 2001
From: Benjamin Fleischer <github@benjaminfleischer.com>
Date: Sun, 3 Jan 2016 23:36:35 -0600
Subject: [PATCH 9/9] Remove outdated regression test

Per https://github.com/rails-api/active_model_serializers/pull/1390#discussion_r48322329
---
 .../test/serializer_test.rb                   | 23 -------------------
 test/fixtures/template.html.erb               |  1 -
 2 files changed, 24 deletions(-)
 delete mode 100644 test/fixtures/template.html.erb

diff --git a/test/active_model_serializers/test/serializer_test.rb b/test/active_model_serializers/test/serializer_test.rb
index c6c10b71..c4773d9b 100644
--- a/test/active_model_serializers/test/serializer_test.rb
+++ b/test/active_model_serializers/test/serializer_test.rb
@@ -6,7 +6,6 @@ module ActiveModelSerializers
       include ActiveModelSerializers::Test::Serializer
 
       class MyController < ActionController::Base
-        TEMPLATE_NAME = 'template'
         def render_using_serializer
           render json: Profile.new(name: 'Name 1', description: 'Description 1', comments: 'Comments 1')
         end
@@ -15,11 +14,6 @@ module ActiveModelSerializers
         def render_some_text
           Rails.version > '4.1' ? render(plain: 'ok') : render(text: 'ok')
         end
-
-        def render_a_template
-          prepend_view_path './test/fixtures'
-          render template: TEMPLATE_NAME
-        end
       end
 
       tests MyController
@@ -64,23 +58,6 @@ module ActiveModelSerializers
         end
         assert_match 'assert_serializer only accepts a String, Symbol, Regexp, ActiveModel::Serializer, or nil', e.message
       end
-
-      def test_does_not_overwrite_notification_subscriptions
-        payloads = []
-        event_name = '!render_template.action_view'
-        ActiveSupport::Notifications.subscribe(event_name) do |_name, _start, _finish, _id, payload|
-          payloads << payload
-        end
-
-        get :render_a_template
-
-        assert_equal 1, payloads.size, 'Only expected one template rendering to be registered'
-        payload = payloads.first
-        assert_equal MyController::TEMPLATE_NAME, payload[:virtual_path]
-        assert_match %r{test/fixtures/#{MyController::TEMPLATE_NAME}.html.erb}, payload[:identifier]
-      ensure
-        ActiveSupport::Notifications.unsubscribe(event_name)
-      end
     end
   end
 end
diff --git a/test/fixtures/template.html.erb b/test/fixtures/template.html.erb
deleted file mode 100644
index 1f87be87..00000000
--- a/test/fixtures/template.html.erb
+++ /dev/null
@@ -1 +0,0 @@
-<p>Hello.</p>