test.Matchers.toThrow

toThrow(

expected?: unknown

): void;

Asserts that a function throws an error.

If expected is a string or RegExp, it will check the message property.
If expected is an Error object, it will check the name and message properties.
If expected is an Error constructor, it will check the class of the Error.
If expected is not provided, it will check if anything has thrown.

@param expected

the expected error, error message, or error pattern

function fail() {
  throw new Error("Oops!");
}
expect(fail).toThrow("Oops!");
expect(fail).toThrow(/oops/i);
expect(fail).toThrow(Error);
expect(fail).toThrow();