never
is a type that a function can return.
If you have a function that always throws an error, that function never returns a value.
function generateError(message: string) {
throw new Error(message);
}
Since above function always throws an error, the function not even returns an undefined
. So, in cases like this, we can specify the function to return never
.
function generateError(message: string): never {
throw new Error(message);
}
If you want to verify if the function does not return anything, try below code:
function generateError(message: string) {
throw new Error(message);
}
const result = generateError("My error");
console.log(result);
Above code does not print anything in console.