e79ae14518
Draper::Decorater provides the object method and we should delegate === to this
method only for these types.
Other classes could respond_to?(:object) so using is_a? clarifies not just any
class implementing object but only classes that are a Draper::Decorator.
Besides this, another major reason is is_a? is much faster than respond_to?
in ActiveRecord models because of the number of methods AR provides and the
layers of delegation. There is a cache specifically for respond_to? [1] because
it's so slow.
Even with this cache, some of our pages are 10% faster by using the is_a? change
from this patch.
The original implementation [2] used the method source, which was later renamed
to object. The tests seem to indicate the intention was to always have
this === delegation to source/object for decorated objects... which is what
Drapper::Decorator types are.
Test changes:
* verify decorated instances of Product and instances derived from
decorated instances of Product are === Product.
* verify unrelated decorated instances and non-decorators that
happen to implement object are not === Product.
[1] https://github.com/rails/rails/blob/4-2-stable/activemodel/lib/active_model/attribute_methods.rb#L343-L351
[2]
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| draper | ||
| generators | ||
| draper.rb | ||