Why is never assignable to every type?

Question

The TypeScript documentation says that

The never type is a subtype of, and assignable to, every type

but doesn\'t m

Answer 1

How type-checking works for assignments?

Take the R-value (right side of assignment). Verify if it can assume a value which the L-value (left side of assignment) can not. If any such value exists, then reject the assignment. Otherwise, it's fine.

Let's see examples:

let x: number;
let y: never;

x = y; // OKAY, can assign any given `never` value to a number

y = x; // Not OKAY, x can be, among other values, 1, which is can not be assigned to never

It looks absurb, as an assignment needs to move some data into the designated storage for a given variable, and no value exists, since it's not a runtime type. In practice though, an assignment from never to any other type, while valid, won't actually run (except if you trick TypeScript with type assertions).

Does that make sense?