"Enforcing new on constructor" style prevents inheritance? about hapi-contrib

[hueniverse]

This is done to protect users of the public API from forgetting to call new. There are two typical ways of doing this, one is passive which is what we do (just prevent it) and active (call new in the constructor).

This is done only in publicly exposed APIs. Internal prototypes don't have that. You should have no reason to use prototypical inheritance from hapi object API interfaces.

[harrytruong]

Thanks for the very quick response!

This is done to protect users of the public API from forgetting to call new. There are two typical ways of doing this, one is passive which is what we do (just prevent it) and active (call new in the constructor).

I agree with the passive method (just preventing it), but the check logic is what I'm surprised by: this.constructor === Constructor instead of this instanceof Constructor.

Just to be clear, I'm not advocating for active protection.

You should have no reason to use prototypical inheritance from hapi object API interfaces.

Haha, I agree. I'm not using hapi's objects in the intended way, but I don't think it hurts to reuse and extend hapi's objects for other projects? The current implementation prevents inheritance, while the alternative would allow for it (and would still passively protect against missing new).

[harrytruong]

[deleted] Commented on wrong issue ticket.

[hueniverse]

What's your use case here?

[harrytruong]

Just repeating myself here for clarity:

I have no real reason. I was playing around with reusing Hapi's components in a side project. When I extended from Server to test something, I saw the implementation, and was just curious about the rationale behind it.

Also pinging @geek here because he added this style rule back in 2012.

Just want to be 100% sure I'm not misunderstanding the reason for this.constructor === Server. (TBH, the fact that it explicitly says // Wrong, makes me very paranoid.)