Laravel 事件调度断言失败

Question

我正在编写一些单元测试来测试数据库事务中间件，出现异常时事务中的所有内容都应该回滚。这段代码工作得很好并且通过了单元测试：

成功的单元测试方法

public function testTransactionShouldRollback()
{
    Event::fake();

    // Ignore the exception so the test itself can continue.
    $this->expectException('Exception');

    $this->middleware->handle($this->request, function () {
        throw new Exception('Transaction should fail');
    });

    Event::assertDispatched(TransactionRolledBack::class);
}

然而，每当我测试一个TransactionBeginning事件时，它都无法断言该事件已被调度。

失败的单元测试方法

public function testTransactionShouldBegin()
{
    Event::fake();

    $this->middleware->handle($this->request, function () {
        return $this->response;
    });

    Event::assertDispatched(TransactionBeginning::class);
}

实际的中间件

public function handle($request, Closure $next)
{
    DB::beginTransaction();

    try {
        $response = $next($request);

        if ($response->exception) {
            throw $response->exception;
        }
    } catch (Throwable $e) {
        DB::rollBack();
        throw $e;
    }

    if (!$response->exception) {
        DB::commit();
    }

    return $response;
}

所有事务事件都会触发事件，DB::beginTransaction, DB::rollBack, DB::commit所有触发事件也应如此。然而，当我测试时，我什至只看到事务回滚事件触发。

在这种情况下其他事件没有触发并且我的assertDispatched失败是否有原因？

Answer 1

我不知道确切的原因（必须更深入地挖掘），但我找到了解决此问题的解决方案。

似乎这里仍然使用默认事件调度程序，因此当您运行Event::fake()数据库连接时使用默认调度程序。解决方案不是仅仅运行：

Event::fake();

跑步：

$fake = Event::fake();
DB::setEventDispatcher($fake);

经过这样的修改后，我的测试运行良好。下面是完整的测试用例类：

<?php

namespace Tests\Feature;

use App\Http\Middleware\TestMiddleware;
use Exception;
use Illuminate\Database\Events\TransactionBeginning;
use Illuminate\Database\Events\TransactionCommitted;
use Illuminate\Database\Events\TransactionRolledBack;
use Illuminate\Http\Request;
use Illuminate\Http\Response;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Event;
use Tests\TestCase;

class ExampleTest extends TestCase
{
    /**
     * @var \App\Http\Middleware\TestMiddleware
     */
    protected $middleware;

    /**
     * @var \Illuminate\Http\Request
     */
    protected $request;

    /**
     * @var \Illuminate\Http\Response
     */
    protected $response;

    public function setUp():void
    {
        parent::setUp();

        Event::fake();

        $this->middleware = new TestMiddleware();

        $this->request = new Request();

        $this->response = new Response();
    }

    public function testTransactionShouldRollback()
    {
        $fake = Event::fake();
        DB::setEventDispatcher($fake);

        // Ignore the exception so the test itself can continue.
        $this->expectException('Exception');

        $this->middleware->handle($this->request, function () {
            throw new Exception('Transaction should fail');
        });

        Event::assertDispatched(TransactionBeginning::class);
        Event::assertDispatched(TransactionRolledBack::class);
        Event::asserNotDispatched(TransactionCommitted::class);
    }

    public function testTransactionShouldBegin()
    {
        $fake = Event::fake();
        DB::setEventDispatcher($fake);

        $this->middleware->handle($this->request, function () {
            return $this->response;
        });

        Event::assertDispatched(TransactionBeginning::class);
        Event::assertNotDispatched(TransactionRolledBack::class);
        Event::assertDispatched(TransactionCommitted::class);
    }
}