Remove ActionController::TestCase from documentation

In Rails 5.1 `ActionController::TestCase` will be moved out of Rails
into it's own gem.

Please use `ActionDispatch::IntegrationTest` going foward.

Because this will be moved to a gem I used `# :stopdoc:` instead of
deleting the documentation. This will remove it from the Rails
documentation but still leave the method documented for when we move it
to a gem.

Guides have been updated to use the routing structure used in Integration
and all test examples have been updated to inherit from
`ActionDispatch::IntegrationTest` instead of `ActionController::TestCase.

Fixes #22496

3 files changed, 17 insertions, 1 deletions

diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index 271a57a7ad..98320f05a3 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1,3 +1,15 @@
+*   `ActionController::TestCase` will be moved to it's own gem in Rails 5.1
+
+    With the speed improvements made to `ActionDispatch::IntegrationTest` we no
+    longer need to keep two separate code bases for testing controllers. In
+    Rails 5.1 `ActionController::TestCase` will be deprecated and moved into a
+    gem outside of Rails source.
+
+    This is a documentation deprecation so that going forward so new tests will use
+    `ActionDispatch::IntegrationTest` instead of `ActionController::TestCase`.
+
+    *Eileen M. Uchitelle*
+
 *   Add a `response_format` option to `ActionDispatch::DebugExceptions`
     to configure the format of the response when errors occur in
     development mode.
diff --git a/actionpack/lib/action_controller/test_case.rb b/actionpack/lib/action_controller/test_case.rb
index 442ffd6d7c..c55720859e 100644
--- a/actionpack/lib/action_controller/test_case.rb
+++ b/actionpack/lib/action_controller/test_case.rb
@@ -7,6 +7,9 @@ require 'action_controller/template_assertions'
 require 'rails-dom-testing'
 
 module ActionController
+  # :stopdoc:
+  # ActionController::TestCase will be deprecated and moved to a gem in Rails 5.1.
+  # Please use ActionDispatch::IntegrationTest going forward.
   class TestRequest < ActionDispatch::TestRequest #:nodoc:
     DEFAULT_ENV = ActionDispatch::TestRequest::DEFAULT_ENV.dup
     DEFAULT_ENV.delete 'PATH_INFO'
@@ -658,4 +661,5 @@ module ActionController
 
     include Behavior
   end
+  # :startdoc:
 end
diff --git a/actionpack/lib/action_dispatch/testing/test_process.rb b/actionpack/lib/action_dispatch/testing/test_process.rb
index c28d701b48..eca0439909 100644
--- a/actionpack/lib/action_dispatch/testing/test_process.rb
+++ b/actionpack/lib/action_dispatch/testing/test_process.rb
@@ -26,7 +26,7 @@ module ActionDispatch
       @response.redirect_url
     end
 
-    # Shortcut for <tt>Rack::Test::UploadedFile.new(File.join(ActionController::TestCase.fixture_path, path), type)</tt>:
+    # Shortcut for <tt>Rack::Test::UploadedFile.new(File.join(ActionDispatch::IntegrationTest.fixture_path, path), type)</tt>:
     #
     #   post :change_avatar, avatar: fixture_file_upload('files/spongebob.png', 'image/png')
     #