Hey there!

I’m updating Programming TypeScript to include assertions in control flow analysis, and was looking for guidance about naming.

Type assertions (x as T) and assertions in control flow analysis (asserts x is T) are similarly named. What’s a good way to call these these features, in a way that doesn’t confuse people and aligns with the way the TS team is communicating it?

A couple of ideas:

1. Rename x as T to “type coercion” or “type casting" (even though it’s not a runtime behavior), and call asserts x is T a “type assertion”
2. Keep x as T as-is (“type assertion”), and call asserts x is T a “user-defined type assertion”, similar to a “user-defined type guard”

Thanks!