Avoid documenting private or external classes

There are a lot of monkey patches inside the code base but there's
no need to document external constants so let's remove them from
the documentation

Also, since there are monkey patches for some test cases classes,
there were sometimes both documented and sneaked under the wrong
section in the sidebar.

Finally, for future references, the `active_support/vendor`
folder has been originally ignored in https://git.io/vDqfA but
no longer exists.

[ci skip]

2 files changed, 14 insertions, 7 deletions

diff --git a/railties/lib/rails/api/task.rb b/railties/lib/rails/api/task.rb
index bc670b1d75..101e8806d0 100644
--- a/railties/lib/rails/api/task.rb
+++ b/railties/lib/rails/api/task.rb
@@ -8,8 +8,7 @@ module Rails
           include: %w(
             README.rdoc
             lib/active_support/**/*.rb
-          ),
-          exclude: "lib/active_support/vendor/*"
+          )
         },
 
         "activerecord" => {
@@ -69,7 +68,11 @@ module Rails
             README.rdoc
             lib/**/*.rb
           ),
-          exclude: "lib/rails/generators/rails/**/templates/**/*.rb"
+          exclude: %w(
+            lib/rails/generators/rails/**/templates/**/*.rb
+            lib/rails/test_unit/*
+            lib/rails/api/generator.rb
+          )
         }
       }
 
diff --git a/railties/lib/rails/test_help.rb b/railties/lib/rails/test_help.rb
index 5fda160012..0f9bf98737 100644
--- a/railties/lib/rails/test_help.rb
+++ b/railties/lib/rails/test_help.rb
@@ -14,10 +14,12 @@ require "active_support/testing/autorun"
 if defined?(ActiveRecord::Base)
   ActiveRecord::Migration.maintain_test_schema!
 
-  class ActiveSupport::TestCase
-    include ActiveRecord::TestFixtures
-    self.fixture_path = "#{Rails.root}/test/fixtures/"
-    self.file_fixture_path = fixture_path + "files"
+  module ActiveSupport
+    class TestCase
+      include ActiveRecord::TestFixtures
+      self.fixture_path = "#{Rails.root}/test/fixtures/"
+      self.file_fixture_path = fixture_path + "files"
+    end
   end
 
   ActionDispatch::IntegrationTest.fixture_path = ActiveSupport::TestCase.fixture_path
@@ -27,6 +29,8 @@ if defined?(ActiveRecord::Base)
   end
 end
 
+# :enddoc:
+
 class ActionController::TestCase
   def before_setup # :nodoc:
     @routes = Rails.application.routes