Fix incompatibility w/ PHP7.2+

[mbeccati]

Mock_ParserResult_*::getParameterMappings() was returning null, which was then passed to count() on Query.php:308, causing a "Parameter must be an array or an object that implements Countable" error.

[lcobucci]

@mbeccati that sounds like a phpunit-mock issue, since when you call createMock() with a concrete class it should stub the public interface of the object...

[mbeccati]

By default, all methods of the original class are replaced with a dummy implementation that just returns null

Which is not what you'd want there, @lcobucci

[Ocramius]

Got a link to the failure? I don't understand the reason for this change.

Specifically, I don't understand why it fails on 7.2 only.

[lcobucci]

Which is not what you'd want there, @lcobucci

@mbeccati We just don't care here if we stub everything or not, you might right when saying that we're just need to do that for the method getSqlExecutor() but there's no reason to change doctrine's test suite if it's passing for the other builds.

Got a link to the failure? I don't understand the reason for this change.

@Ocramius It's failing for nightly builds (like https://travis-ci.org/doctrine/doctrine2/jobs/177333526)

[mbeccati]

@Ocramius https://revive.beccati.com/bamboo/browse/PHP-DOCTR-MAS-919/test/case/11810654 w/ php-src master, since count() has been restricted to work only on array|Countable.

[Ocramius]

Merging, since I feel like digging further into this is just going to be more pain.

The fix is simple/easy: let's roll with it, since it's a test-suite change only.

[mbeccati]

Thanks @Ocramius. Since I've did that digging already, I'll try to write it down for posterity:

1. \Doctrine\ORM\Query\ParserResult has a private property $_parameterMappings, which is initialised as an empty array;
2. such property is never overwritten with non-array values;
3. \Doctrine\ORM\Query\ParserResult::getParameterMappings() returns its value, which means it is always returning an array;
4. Doctrine/ORM/Query.php on line 306 calls getParameterMappings() and on line 308 calls count() on its return value, which is guaranteed to be an array;
5. Doctrine/Tests/ORM/Functional/QueryCacheTest.php was injecting a stub of ParserResult that returned null for all methods but getSqlExecutor();
6. that means that getParameterMappings() was unexpectedly returning null and causing the above count() to fail on PHP 7.2 since the introduction of this RFC;
7. the test was fixed by using a mock that only overrides getSqlExecutor().