获取PHPUnit ajax测试的cookie

I'm trying to write some PHPUnit tests for ajax endpoints. I can do this no sweat when the user doesn't have to be logged in. But to test the endpoint in question, the user does have to be logged in and I want to get the cookie programmatically as part of the test. Basically the test I want to run looks like:

    $url = "https://example.com/ajax/endpoint";
    $fields = array(
        'name'=>'test '.rand(),       
        'host'=>rand(0,255).'.'.rand(0,255).'.'.rand(0,255).'.'.rand(0,255),
        'port'=>rand(1,1000)
    );
    $fields_string = "";
    foreach ($fields as $key=>$value) {
        $fields_string .= $key.'='.$value.'&';
    }
    $fields_string = rtrim($fields_string, '&');
    ob_start();
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $fields_string);
    curl_setopt($ch, CURLOPT_COOKIE, $userCookie);
    curl_setopt($ch, CURLOPT_URL, $url);
    $response = curl_exec($ch);
    $this->assertEquals(true, $response);
    $json = ob_get_contents();
    $return = json_decode($json);
    $this->assertEquals('false', $return->success);
    $this->assertEquals('', $return->data);
    ob_end_clean();

But I don't know a good way to get $userCookie other than opening a browser, logging in, and then reading PHPSESSID from the cookies in the browser. How can I get the cookie for this without grabbing it manually? I'd like to be able to get it from a curl request to the login endpoint:

    $url = "https://example.com/ajax/login";
    $fields = array(
        'username'=>$username,
        'password'=>$password
    );
    $fields_string = "";
    foreach ($fields as $key=>$value) {
        $fields_string .= $key.'='.$value.'&';
    }
    $fields_string = rtrim($fields_string, '&');
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $fields_string);
    curl_setopt($ch, CURLOPT_URL, $url);
    $response = curl_exec($ch);

Does anything stop you to grab it programmatically?

$ch = curl_init('https://example.com/login');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, "login=root&password=toor");
curl_setopt($ch, CURLOPT_HEADER, 1);

$result = curl_exec($ch);
preg_match_all('/^Set-Cookie: PHPSESSID=(.*?);/mi', $result, $matches);
$userCookie = $matches[1];

You're halfway there with your login cURL request. What you need to do is retrieve the cookie from the response headers to get the PHPSESSID.

How to get response headers with cURL has been asked in another question you can find here.

Once you've got the response headers, you'll have to parse it to get the Set-Cookie header. Using the content of that header for your subsequent tests should work from there.