A type is not the name you are looking for

Naming is one of the biggest challenges in programming. Meaningful names are crucial because developers spend far more time reading code than writing it. I’ve recently discovered that type is one of the most misused names in code.

I joined a team where conversation was one of our main entities. At the time, it already had a type property. What do you think: what is the type of a conversation? Take a moment to think about it before you read on…

In this case, the type property had an enumerated type taking the value OUTGOING or INCOMING. So far, so good. Up to that point, all conversations were telephone conversations. But surprise surprise… we decided to support SMS conversations as well. So what’s next? It’s time to add a new type property… Wait… What?!

That’s right. We needed to handle new types: PHONE and SMS. So what now?

What if we get a request to distinguish between INTERNAL and EXTERNAL conversations? How do we add another type?

In our case:

• OUTGOING and INCOMING could be called direction,
• PHONE and SMS could be called medium,
• INTERNAL and EXTERNAL could be called scope.

Of course, it is possible that these different names are still too broad and that we should think more deeply. But for sure, type is often too generic and too broad as a property name.

TOTD: Think twice before naming a property type. Possibly it is not the name you are looking for.