It seems like you code against a concrete implementation and not the interface Traversable as the method count() does only exist in the following implementations of said interface: ArrayIterator, ArrayObject, CachingIterator, Doctrine\Common\Collections\AbstractLazyCollection, Doctrine\Common\Collections\ArrayCollection, Doctrine\ORM\LazyCriteriaCollection, Doctrine\ORM\PersistentCollection, Doctrine\ORM\Tools\Console\MetadataFilter, Doctrine\ORM\Tools\Pagination\Paginator, GlobIterator, HttpMessage, HttpRequestPool, Issue523, MongoCursor, MongoGridFSCursor, PHPUnit\Framework\DataProviderTestSuite, PHPUnit\Framework\TestSuite, PHP_Token_Stream, Pagerfanta\Pagerfanta, Phar, PharData, PharIo\Manifest\AuthorCollection, PharIo\Manifest\BundledComponentCollection, PharIo\Manifest\RequirementCollection, RecursiveArrayIterator, RecursiveCachingIterator, SQLiteResult, SebastianBergmann\CodeCoverage\Node\Directory, SimpleXMLElement, SimpleXMLIterator, SplDoublyLinkedList, SplFixedArray, SplHeap, SplMaxHeap, SplMinHeap, SplObjectStorage, SplPriorityQueue, SplQueue, SplStack, TheSeer\Tokenizer\TokenCollection, Zenstruck\Porpaginas\Doc...ry\DBALObjectRepository, Zenstruck\Porpaginas\Pager.
Let’s take a look at an example:
interfaceUser{/** @return string */publicfunctiongetPassword();}classMyUserimplementsUser{publicfunctiongetPassword(){// return something}publicfunctiongetDisplayName(){// return some name.}}classAuthSystem{publicfunctionauthenticate(User$user){$this->logger->info(sprintf('Authenticating %s.',$user->getDisplayName()));// do something.}}
In the above example, the authenticate() method works fine as long as you just pass
instances of MyUser. However, if you now also want to pass a different implementation
of User which does not have a getDisplayName() method, the code will break.
classAuthSystem{publicfunctionauthenticate(User$user){if($userinstanceofMyUser){$this->logger->info(/** ... */);}// or alternativelyif(!$userinstanceofMyUser){thrownew\LogicException('$user must be an instance of MyUser, '.'other instances are not supported.');}}}
Note: PHP Analyzer uses reverse abstract interpretation to narrow down the types
inside the if block in such a case.
kbond /
porpaginas
Let’s take a look at an example:
In the above example, the authenticate() method works fine as long as you just pass instances of MyUser. However, if you now also want to pass a different implementation of User which does not have a getDisplayName() method, the code will break.
Available Fixes
Change the type-hint for the parameter:
Add an additional type-check:
Add the method to the interface: