The argument of array_key_exists cannot be null

[baijunyao]

#796

[ob-stripe]

I'm still not sure what could cause $this->filters to be null, but more defensive programming can't hurt :)

Thanks for the contribution!

[baijunyao]

1. For example, I call the all() method of Account

    foreach (\Stripe\Account::all()->autoPagingIterator() as $payout) {
        var_dump($payout);
    }

2. lib/ApiOperations/All.php
   The all() method calls the setFilters() method

    public static function all($params = null, $opts = null)
    {
        self::_validateParams($params);
        $url = static::classUrl();

        list($response, $opts) = static::_staticRequest('get', $url, $params, $opts);
        $obj = \Stripe\Util\Util::convertToStripeObject($response->json, $opts);
        if (!($obj instanceof \Stripe\Collection)) {
            throw new \Stripe\Exception\UnexpectedValueException(
                'Expected type ' . \Stripe\Collection::class . ', got "' . get_class($obj) . '" instead.'
            );
        }
        $obj->setLastResponse($response);
        $obj->setFilters($params);
        return $obj;
    }

• $params = null.
• $obj->setFilters($params);

3. lib/Collection.php

    public function setFilters($filters)
    {
        $this->filters = $filters;
    }

$this->filters = null

[ob-stripe]

Ah, I see. Thanks for the explanation (and the patch!).

[baijunyao]

So, I think #796 may need to be merged, this completely solves the problem that filters maybe null, Otherwise we don't know where it will be called in a place where filters is not allowed to be null.