Gateway tests assume any string is valid for a gateway parameter

[judgej]

The tests are in here, and send uniqu() into every gateway default parameter to see what comes back. This fails when the gateway is not accepting a string, and either casts it to another value or throws an exception.

https://github.com/thephpleague/omnipay-tests/blob/master/src/Omnipay/Tests/GatewayTestCase.php

Gateway classes define a set of defaults, and those defaults can tell the test what would be acceptable. Defaults are commonly 0 (integer), '' (string) and ['foo','bar'] (array). This can be used to set up the test to generate a random number, a random string, or pick a random element from the array.

[judgej]

I'm using this at the moment to generate a random gateway parameter, rather than uniqid():

    protected function makeUnique($default)
    {
        switch (gettype($default)) {
            case 'integer':
                $value = rand(100000, 999999);
                break;

            case 'array':
                $value = $default[array_rand($default)];
                break;

            case 'string':
            default:
                $value = uniqid();
                break;
        }

        return $value;
    }

I'll give it some more testing before getting a PR together. Using this can mean having to avoid an awful lot of core test overrides in a gateway driver.

This can also be used to improve the parameter entry form on the example application - showing whether a parameter needs to be a number, string or drop-down of possible values.

[coatesap]

Completely agree - we've encountered the same issue. The test always issues a uniqueid but the getter might quite rightly want to return a boolean, for instance. Your proposed solution seems like a smart workaround.