Assert
Assert is a PHP library that provides an alternative to PHP's assert() that allows for a simple and reliable way to check preconditions and postconditions in PHP code.
It was proposed as a MediaWiki RFC, but is completely generic and can be used by any PHP program or library.
Usage[edit]
The Assert class provides several static methods for checking various kinds of assertions. The most common kind is to check the type of a parameter, typically in a constructor or a setter method:
use Wikimedia\Assert\Assert;
function setFoo( $foo ) {
Assert::parameterType( 'integer', $foo, 'foo' );
Assert::parameter( $foo > 0, 'foo', 'must be greater than 0' );
}
function __construct( $bar, array $bazz ) {
Assert::parameterType( 'Me\MyApp\SomeClass', $bar );
Assert::parameterElementType( 'int', $bazz );
}
Checking parameters, or other assertions such as pre- or postconditions, is not recommended for performance critical regions of the code, since evaluating expressions and calling the assertion functions costs time.