What does this TypeScript code demonstrate? type IsNever = [T] extends [never] ? true : false;

Question

TypeScript Associate — Hard

What does this TypeScript code demonstrate? type IsNever = [T] extends [never] ? true : false;

Accepted Answer

The TypeScript code demonstrates the use of a tuple to prevent conditional type distribution, accurately detecting when T is never. Without the tuple, T extends never would always result in never for a naked type parameter.