Usually users extends tests classes doing something like:
ActionView::TestCase.include MyCustomTestHelpers
This is bad because it will load the ActionView::TestCase right aways
and this will load ActionController::Base making its on_load hooks to
execute early than it should.
One way to fix this is using the on_load hooks of the components like:
ActiveSupport.on_load(:action_view) do
ActionView::TestCase.include MyCustomTestHelpers
end
The problem with this approach is that the test extension will be only
load when ActionView::Base is loaded and this may happen too late in the
test.
To fix this we are adding hooks to people extend the test classes that
will be loaded exactly when the test classes are needed.