Check existence of source class in TestFramework FactoryGenerator

Would anything speak against a check for the existence of the source class in Magento\Framework\TestFramework\Unit\Autoloader\FactoryGenerator?

The current code looks like:

private function isFactory($className)
    {
        if (!preg_match('/[\\\A-Z]/', substr(ltrim($className), 0, 1))) {
            return false;
        }
        $sourceName = rtrim(substr($className, 0, -strlen('Factory')), '\\');

        return $sourceName . 'Factory' == $className;
    }

If it would be changed to the following, there would be another degree of safety in unit tests, since it checks for the validity of a factory:

private function isFactory($className)
    {
        if (!preg_match('/[\\\A-Z]/', substr(ltrim($className), 0, 1))) {
            return false;
        }
        $sourceName = rtrim(substr($className, 0, -strlen('Factory')), '\\');

        if (!\class_exists($sourceName))
        {
            return false;
        }

        return $sourceName . 'Factory' == $className;
    }

It can also prevent missspelling errors. Currently unit tests can pass although the code won't work in production.

Any opinions on this?

magento / community-features

Check existence of source class in TestFramework FactoryGenerator #303