Issue #2873732 by vijaycs85, GaëlG: Array to string conversion in...

   */

  public function getContext($cookie = NULL) {

    if ($cookie === NULL) {

      return $this->requestStack->getCurrentRequest()->cookies->all();

      $cookies = $this->requestStack->getCurrentRequest()->cookies->all();

      // Sort the cookies by names, to always set the same context if the cookies

      // are the same but in a different order.

      ksort($cookies);

      // Use http_build_query() to get a short string from the cookies array.

      return http_build_query($cookies);

    }

    else {

      return $this->requestStack->getCurrentRequest()->cookies->get($cookie);

<?php

namespace Drupal\Tests\Core\Cache\Context;

use Drupal\Core\Cache\Context\CookiesCacheContext;

use Drupal\Tests\UnitTestCase;

use Symfony\Component\HttpFoundation\Request;

use Symfony\Component\HttpFoundation\RequestStack;

/**

 * @coversDefaultClass \Drupal\Core\Cache\Context\CookiesCacheContext

 * @group Cache

 */

class CookieCacheContextTest extends UnitTestCase {

  /**

   * @covers ::getContext

   *

   * @dataProvider providerTestGetContext

   */

  public function testGetContext($cookies, $cookie_name, $context) {

    $request_stack = new RequestStack();

    $request = Request::create('/', 'GET');

    foreach ($cookies as $cookie => $value) {

      $request->cookies->set($cookie, $value);

    }

    $request_stack->push($request);

    $cache_context = new CookiesCacheContext($request_stack);

    $this->assertSame($cache_context->getContext($cookie_name), $context);

  }

  /**

   * Provides a list of cookies and expected cache contexts.

   */

  public function providerTestGetContext() {

    return [

      [['foo' => 1, 'bar' => 2, 'baz' => 3], 'foo', 1],

      // Context is ordered by cookie name.

      [['foo' => 1, 'bar' => 2, 'baz' => 3], NULL, 'bar=2&baz=3&foo=1'],

    ];

  }

}