UndefinedThrowsDocblock

A @throws docblock references an exception class that does not exist or is not imported.

Example

<?php
/**
 * @throws UndefinedException
 */
function process(): void {
    // No such class exists
}

How to fix

Ensure the exception class exists and is properly imported:

<?php
use InvalidArgumentException;

/**
 * @throws InvalidArgumentException
 */
function process(string $value): void {
    if ($value === '') {
        throw new InvalidArgumentException('Value cannot be empty');
    }
}