<?php
/*
* This file is part of PHPUnit.
*
* (c) Sebastian Bergmann <sebastian@phpunit.de>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace PHPUnit\Framework\Constraint;

use Countable;

/**
* Constraint that checks whether a variable is empty().
*/
class IsEmpty extends Constraint
{
/**
* Evaluates the constraint for parameter $other. Returns true if the
* constraint is met, false otherwise.
*
* @param mixed $other Value or object to evaluate.
*
* @return bool
*/
protected function matches($other)
{
if ($other instanceof Countable) {
return \count($other) === 0;
}

return empty($other);
}

/**
* Returns a string representation of the constraint.
*
* @return string
*/
public function toString()
{
return 'is empty';
}

/**
* Returns the description of the failure
*
* The beginning of failure messages is "Failed asserting that" in most
* cases. This method should return the second part of that sentence.
*
* @param mixed $other Evaluated value or object.
*
* @return string
*/
protected function failureDescription($other)
{
$type = \gettype($other);

return \sprintf(
'%s %s %s',
$type[0] == 'a' || $type[0] == 'o' ? 'an' : 'a',
$type,
$this->toString()
);
}
}