可能是因为您在测试中使用了完整的URL而不是相对URL。WebTestCase类自动创建一个模拟浏览器的客户端，但它实际上并不发送HTTP请求，而是直接调用Symfony应用程序。
请尝试以下代码：

<?php

// php bin/phpunit tests/Controller/DataControllerTest.php
namespace App\Tests\Controller;

use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;

class DataControllerTest extends WebTestCase
{
    public function testSomething(): void
    {
        $client = static::createClient();
        // Use a relative path instead of a full URL
        $crawler = $client->request('GET', '/get/data?active=1&sort=desc');

        $this->assertResponseIsSuccessful();
        $this->assertSelectorTextContains('h1', 'Hello World');
    }
}

这样，客户端将自动使用默认的域和端口（通常是localhost：8000）来访问应用程序。当然，您也可以在创建客户端时传递数组参数来更改默认值：

$client = static::createClient(['HTTP_HOST' => 'masch1']);

有关WebTestCase类和客户端的详细信息，请参阅以下链接：

• Testing (Symfony Docs)
• Using Symfony Bundle FrameworkBundle Test WebTestCase instead of PHPUnitFrameworkTestCase as a base class for our tests gives us a nice abstraction for functional tests. The $client variable simulates a browser. Instead of making HTTP calls to the server though, it calls the Symfony application directly.
• How to get the current URL after a redirect in a Symfony2 WebTestCase?

尝试在控制台中执行以下命令：

php bin/console debug:router

然后使用“路径”列中的值。路径不需要指定协议和域名：

$client->request('GET', '/value/from/path/column');

如果此建议没有帮助，请显示如何描述到控制器的路由，以及上面提到的命令显示的值。

我所需要的只是正确的插入URL的方法。

<?php

// php bin/phpunit tests/Controller/DataControllerTest.php
namespace App\Tests\Controller;

use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;

class DataControllerTest extends WebTestCase
{
    public function testSomething(): void
    {
        $client = static::createClient(['HTTP_HOST' => 'masch1']);
        $client->request('GET', '/get/data?active=1&sort=desc');
        $response = $client->getResponse();
        $content = $response->getContent();
        
        // Check json data with first record
        $jsonData = json_decode($content, true)[0];

        // check fields
        $this->assertArrayHasKey('field1', $jsonData);
        $this->assertArrayHasKey('field2', $jsonData);
        $this->assertArrayHasKey('field3', $jsonData);

        // Check field types
        $this->assertIsInt($jsonData['field1']);

        $this->assertEquals(200, $response->getStatusCode());

        $this->assertResponseIsSuccessful();
        
    }
}