What is the purpose of the 'never' type?

The never type in TypeScript is used to denote values that never occur. This means that a function with a return type of never will never complete normally — for example, it always throws an error or enters an infinite loop.

Example usage:

function throwError(message: string): never {
  throw new Error(message);
}

function infiniteLoop(): never {
  while(true) {}
}

never helps the compiler understand that code after such function calls will not continue, which improves type checking and prevents errors.