Test contents of return array in PHPSpec - testing

Question

Say I have this method of a RuleFactory:
public function makeFromArray($rules)
{
$array = [];
foreach ($rules as $rule) {
$array[] = new Rule($rule[0], $rule[1]);
}
return $array;
}
I want to test that the return array contains Rule elements. Here is my test:
function it_should_create_multiple_rules_at_once()
{
$rules = [
['required', 'Please provide your first name'],
['alpha', 'Please provide a valid first name']
];
$this->makeFromArray($rules)->shouldHaveCount(2);
$this->makeFromArray($rules)[0]->shouldBeInstanceOf('Rule');
$this->makeFromArray($rules)[1]->shouldBeInstanceOf('Rule');
}
But this does not work, it throws an error in PHPSpec.
The strange thing is that I can do this just fine on other methods that return arrays, but for some reason I cannot do that here.
The error I get is this:
! it should create multiple rules at once
method [array:2] not found
How do I test the contents of this return array, WITHOUT creating my own inline matcher?

Answer 1

Your method accepts a single rule, not all of them. The spec should be:
$this->makeFromArray($rules)->shouldHaveCount(2);
$this->makeFromArray($rules[0])[0]->shouldBeAnInstanceOf('Rule');
$this->makeFromArray($rules[1])[1]->shouldBeAnInstanceOf('Rule');
Or, to avoid multiple calls:
$rules = $this->makeFromArray($rules);
$rules->shouldHaveCount(2);
$rules[0]->shouldBeAnInstanceOf('Rule');
$rules[1]->shouldBeAnInstanceOf('Rule');
Still, the most readable version would be the one leveraging a custom matcher:
$rules->shouldHaveCount(2);
$rules->shouldContainOnlyInstancesOf('Rule');