What does the following variadic tuple type compute? type Concat = […A, …B];

Question

TypeScript Professional — Hard

What does the following variadic tuple type compute? type Concat = […A, …B];

Accepted Answer

The variadic tuple type Concat = [...A, ...B] computes a new tuple type that is the concatenation of tuples A and B with fully preserved positional types. This means that the resulting tuple will maintain the order and types of elements from both A and B.