require-tothrow-message.md

Require a message for toThrow() (require-tothrow-message)

toThrow(), and its alias toThrowError(), are used to check if an error is thrown by a function call, such as in expect(() => a()).toThrow(). However, if no message is defined, then the test will pass for any thrown error. Requiring a message ensures that the intended error is thrown.

Rule details

This rule triggers a warning if toThrow() or toThrowError() is used without an error message.

Default configuration

The following patterns are considered warnings:

expect(() => a()).toThrow();

expect(() => a()).toThrowError();

await expect(a()).rejects.toThrow();

await expect(a()).rejects.toThrowError();

The following patterns are not considered warnings:

expect(() => a()).toThrow('a');

expect(() => a()).toThrowError('a');

await expect(a()).rejects.toThrow('a');

await expect(a()).rejects.toThrowError('a');