<?PHP
function autoloader($dir){
    spl_autoload_register(function($name) use ($dir){
        $name = str_replace(‘\\‘,DIRECTORY_SEPARATOR,$name);
        require $dir.DIRECTORY_SEPARATOR.$name.‘.PHP‘;
    });
}
define(‘ROOT‘,__DIR__);
autoloader(ROOT);

<?PHP
class Money
{
    private $amount;
    public function __construct($amount)
    {
        $this->amount = $amount;
    }
    public function getAmount()
    {
        return $this->amount;
    }
    public function negate()
    {
        return new Money(-1*$this->amount);
    }
}

<?PHP

use PHPUnit\Framework\TestCase;

class MoneyTest extends TestCase
{
    public function testCanBeNegated()
    {
        $a = new Money(1);
        $b = $a->negate();
        $this->assertEquals(-1,$b->getAmount());
    }
}

AssertTrue/AssertFalse    断言是否为真值还是假
AssertEquals　　　　　　　　判断输出是否和预期的相等
AssertGreaterThan         断言结果是否大于某个值，同样的也有LessThan(小于),GreaterThanOrEqual(大于等于)，
LessThanOrEqual           (小于等于).
AssertContains            判断输入是否包含指定的值
AssertType                判断是否属于指定类型
AssertNull                判断是否为空值
AssertFileExists          判断文件是否存在
AssertRegExp              根据正则表达式判断