CollectionInputFilter throws exception on scalar input

[autowp]

    public function testCollectionInputFilterMustNotThrowsExceptionOnScalar()
    {
        $inputFilterManager = $this->getApplicationServiceLocator()->get('InputFilterManager');

        $factory = new \Zend\InputFilter\Factory($inputFilterManager);
        $inputFilter = $factory->createInputFilter([
            'type' => \Zend\InputFilter\CollectionInputFilter::class,
        ]);

        $inputFilter->setData('asd'); // throws Zend\InputFilter\Exception\InvalidArgumentException: Zend\InputFilter\CollectionInputFilter::setData expects an array or Traversable collection; invalid collection of type string provided
    }

That breaks to use input-filter especially where used nested collection filters.

[weierophinney]

@autowp That's expected behavior. Collections require that the incoming data is an array or traversable. If you're seeing that, it means the client-side code is submitting something that the input filter cannot deal with. As such, you have two options:

• If this is from a form-based submission, fix the markup to ensure the submitted values are structured correctly.
• If this is within an API, you can either let that bubble out, and have your error handler report a client-side error to the user, or manually wrap the setData() call in a try/catch block so you can report it yourself.

[autowp]

Ok. But that looks not symmetrical to scalar validations like StringLength where wrong type never follow to Exception (->isValid([]))

[weierophinney]

Validation is a separate subsystem, and independent from the input filters. Additionally, in this case, the exception happens before any validation is even attempted; it's thrown precisely because the value for would likely lead to serious errors further down the stack, including hydrators, filters, and validators.