Wie schreibe ich PHP-Unit-Tests?

composer require --dev phpunit/phpunit ^6.2

composer require monolog/monolog

"require": { 

    "monolog/monolog": "^1.23",

   },

"require-dev": {

       "phpunit/phpunit": "^6.2"

   },

<?php
/**
 * 1、composer 安装Monolog日志扩展，安装phpunit单元测试扩展包
 * 2、引入autoload.php文件
 * 3、测试案例
 *
 *
 */
namespace App\tests;
require_once __DIR__ . &#39;/../vendor/autoload.php&#39;;
define("ROOT_PATH", dirname(__DIR__) . "/"); 
use Monolog\Logger;
use Monolog\Handler\StreamHandler; 
use PHPUnit\Framework\TestCase;
class StackTest extends TestCase
{
    public function testPushAndPop()
    {
        $stack = [];
        $this->assertEquals(0, count($stack));
        array_push($stack, 'foo');
 
        // 添加日志文件,如果没有安装monolog，则有关monolog的代码都可以注释掉
        $this->Log()->error('hello', $stack);
 
        $this->assertEquals('foo', $stack[count($stack)-1]);
        $this->assertEquals(1, count($stack)); 
        $this->assertEquals('foo', array_pop($stack));
        $this->assertEquals(0, count($stack));
    }
 
    public function Log()
    {
        // create a log channel
        $log = new Logger('Tester');
        $log->pushHandler(new StreamHandler(ROOT_PATH . 'storage/logs/app.log', Logger::WARNING));
        $log->error("Error");
        return $log;
    }
}

 framework#  ./vendor/bin/phpunit tests/StackTest.php
 
// 或者可以省略文件后缀名
//  ./vendor/bin/phpunit tests/StackTest

➜  framework# ./vendor/bin/phpunit tests/StackTest.php
PHPUnit 6.4.1 by Sebastian Bergmann and contributors. 
.                                                                   1 / 1 (100%)
Time: 56 ms, Memory: 4.00MB
OK (1 test, 5 assertions)