Private classes in Ruby
One of the most common way to make some part of your code more understandable and explicit is to extract a class. However, many times this class is not intended for public usage. It’s an implementation detail of a bigger unit. It should not be used be anyone else but the module in which it is defined.
So how do we hide such class so that others are not tempted to use it? So that it is clear that it is an implementation detail?
I recently noticed that many people don’t know that since Ruby 1.9.3 you can make a constant private. And that’s your answer to how.
Person class can use
# => 1234vW74X&
But others cannot access it.
# NameError: private constant Person::Secret referenced
Person is the public API that you expose to other parts of the system and
Person::Secret is just an
You should probably not test
Person::Secret directly as well but rather through the public
that your clients are going to use. That way your tests won’t be brittle and depended on implementation.
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