[Cloud Tasks] Testing after release v2.0.0

[Daniel-I-Am]

I maintain a small helper library in-house to allow our development team to not worry about the Google code and differences between development environment (locally) and production (GCP) by implementing the Psr-18 standard with an implementation using Cloud Tasks. We depend on Cloud Tasks for production use, but fall back to a simple HTTP Client implementation for development.

V2 of the Cloud Tasks library was released a couple days ago with some major changes. The most important one for me being that the Client class was marked final therefor no longer mockable in unit tests. From what I can tell there is no interface to allow mocking either.

I have a simple question, how can I test code interacting with the Cloud Tasks client library using PHPUnit now?

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Here's a sample of a test I had before, which is no longer possible with the new final Google\Cloud\Tasks\V2\Client\CloudTasksClient, as far as I know:

<?php

declare(strict_types=1);

namespace tests\<redacted>\CloudTasksDispatcher\Psr18;

use Google\Cloud\Tasks\V2\CloudTasksClient as GCPCloudTasksClient;
use Google\Cloud\Tasks\V2\Task;
use GuzzleHttp\Psr7\Request;
use Lukasoppermann\Httpstatus\Httpstatuscodes;
use PHPUnit\Framework\Assert;
use PHPUnit\Framework\TestCase;
use Psr\Http\Message\ResponseInterface;
use <redacted>\CloudTasksDispatcher\Psr18\CloudTasksClient;

final class CloudTasksClientTest extends TestCase
{
    public function testItSendsValidRequest(): void
    {
        // Create a Task object with an ID set
        $task = new Task();
        $task->setName('MyRandomTaskID');

        // Instantiate a Mock version of the official GCP Client Library's Client class
        $mockCloudTasksClient = $this->getMockBuilder(GCPCloudTasksClient::class)->disableOriginalConstructor()->getMock();
        $mockCloudTasksClient->expects($this->once())->method('createTask')->willReturn($task);

        // Instantiate our custom Psr-18 compatible Cloud Tasks Client class
        $client = new CloudTasksClient(
            $mockCloudTasksClient,
            'mockedQueueId',
            'audience',
            '[email protected]',
        );

        // Send a Psr-18 request
        $mockRequest = new Request('POST', 'https://my-uri/');

        $response = $client->sendRequest($mockRequest);

        // Check the results are as expected
        Assert::assertInstanceOf(ResponseInterface::class, $response);
        Assert::assertSame($response->getBody()->getContents(), $task->getName());
        Assert::assertSame($response->getStatusCode(), Httpstatuscodes::HTTP_ACCEPTED);
    }
}