Security update for Core, with self-updated composer
[yaffs-website] / web / core / modules / page_cache / tests / src / Functional / PageCacheTest.php
diff --git a/web/core/modules/page_cache/tests/src/Functional/PageCacheTest.php b/web/core/modules/page_cache/tests/src/Functional/PageCacheTest.php
new file mode 100644 (file)
index 0000000..bf4951d
--- /dev/null
@@ -0,0 +1,646 @@
+<?php
+
+namespace Drupal\Tests\page_cache\Functional;
+
+use Drupal\Component\Datetime\DateTimePlus;
+use Drupal\Core\Site\Settings;
+use Drupal\Core\Url;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\Core\Cache\Cache;
+use Drupal\Tests\BrowserTestBase;
+use Drupal\Tests\system\Functional\Cache\AssertPageCacheContextsAndTagsTrait;
+use Drupal\user\RoleInterface;
+
+/**
+ * Enables the page cache and tests it with various HTTP requests.
+ *
+ * @group page_cache
+ */
+class PageCacheTest extends BrowserTestBase {
+
+  use AssertPageCacheContextsAndTagsTrait;
+
+  protected $dumpHeaders = TRUE;
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['test_page_test', 'system_test', 'entity_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->config('system.site')
+      ->set('name', 'Drupal')
+      ->set('page.front', '/test-page')
+      ->save();
+  }
+
+  /**
+   * Test that cache tags are properly persisted.
+   *
+   * Since tag based invalidation works, we know that our tag properly
+   * persisted.
+   */
+  public function testPageCacheTags() {
+    $config = $this->config('system.performance');
+    $config->set('cache.page.max_age', 300);
+    $config->save();
+
+    $path = 'system-test/cache_tags_page';
+    $tags = ['system_test_cache_tags_page'];
+    $this->drupalGet($path);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+
+    // Verify a cache hit, but also the presence of the correct cache tags.
+    $this->drupalGet($path);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+    $cid_parts = [\Drupal::url('system_test.cache_tags_page', [], ['absolute' => TRUE]), 'html'];
+    $cid = implode(':', $cid_parts);
+    $cache_entry = \Drupal::cache('page')->get($cid);
+    sort($cache_entry->tags);
+    $expected_tags = [
+      'config:user.role.anonymous',
+      'http_response',
+      'pre_render',
+      'rendered',
+      'system_test_cache_tags_page',
+    ];
+    $this->assertIdentical($cache_entry->tags, $expected_tags);
+
+    Cache::invalidateTags($tags);
+    $this->drupalGet($path);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+  }
+
+  /**
+   * Test that the page cache doesn't depend on cacheability headers.
+   */
+  public function testPageCacheTagsIndependentFromCacheabilityHeaders() {
+    // Disable the cacheability headers.
+    $this->setContainerParameter('http.response.debug_cacheability_headers', FALSE);
+    $this->rebuildContainer();
+    $this->resetAll();
+
+    $path = 'system-test/cache_tags_page';
+    $tags = ['system_test_cache_tags_page'];
+    $this->drupalGet($path);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+
+    // Verify a cache hit, but also the presence of the correct cache tags.
+    $this->drupalGet($path);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+    $cid_parts = [\Drupal::url('system_test.cache_tags_page', [], ['absolute' => TRUE]), 'html'];
+    $cid = implode(':', $cid_parts);
+    $cache_entry = \Drupal::cache('page')->get($cid);
+    sort($cache_entry->tags);
+    $expected_tags = [
+      'config:user.role.anonymous',
+      'http_response',
+      'pre_render',
+      'rendered',
+      'system_test_cache_tags_page',
+    ];
+    $this->assertIdentical($cache_entry->tags, $expected_tags);
+
+    Cache::invalidateTags($tags);
+    $this->drupalGet($path);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+  }
+
+  /**
+   * Tests support for different cache items with different request formats
+   * specified via a query parameter.
+   */
+  public function testQueryParameterFormatRequests() {
+    $config = $this->config('system.performance');
+    $config->set('cache.page.max_age', 300);
+    $config->save();
+
+    $accept_header_cache_url = Url::fromRoute('system_test.page_cache_accept_header');
+    $accept_header_cache_url_with_json = Url::fromRoute('system_test.page_cache_accept_header', ['_format' => 'json']);
+
+    $this->drupalGet($accept_header_cache_url);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS', 'HTML page was not yet cached.');
+    $this->drupalGet($accept_header_cache_url);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'HTML page was cached.');
+    $this->assertRaw('<p>oh hai this is html.</p>', 'The correct HTML response was returned.');
+
+    $this->drupalGet($accept_header_cache_url_with_json);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS', 'Json response was not yet cached.');
+    $this->drupalGet($accept_header_cache_url_with_json);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Json response was cached.');
+    $this->assertRaw('{"content":"oh hai this is json"}', 'The correct Json response was returned.');
+
+    // Enable REST support for nodes and hal+json.
+    \Drupal::service('module_installer')->install(['node', 'rest', 'hal', 'basic_auth']);
+    $this->drupalCreateContentType(['type' => 'article']);
+    $node = $this->drupalCreateNode(['type' => 'article']);
+    $node_uri = $node->urlInfo();
+    $node_url_with_hal_json_format = $node->urlInfo('canonical')->setRouteParameter('_format', 'hal_json');
+
+    $this->drupalGet($node_uri);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+    $this->assertEqual($this->drupalGetHeader('Content-Type'), 'text/html; charset=UTF-8');
+    $this->drupalGet($node_uri);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+    $this->assertEqual($this->drupalGetHeader('Content-Type'), 'text/html; charset=UTF-8');
+
+    // Now request a HAL page, we expect that the first request is a cache miss
+    // and it serves HTML.
+    $this->drupalGet($node_url_with_hal_json_format);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+    $this->assertEqual($this->drupalGetHeader('Content-Type'), 'application/hal+json');
+    $this->drupalGet($node_url_with_hal_json_format);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+    $this->assertEqual($this->drupalGetHeader('Content-Type'), 'application/hal+json');
+
+    // Clear the page cache. After that request a HAL request, followed by an
+    // ordinary HTML one.
+    \Drupal::cache('page')->deleteAll();
+    $this->drupalGet($node_url_with_hal_json_format);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+    $this->assertEqual($this->drupalGetHeader('Content-Type'), 'application/hal+json');
+    $this->drupalGet($node_url_with_hal_json_format);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+    $this->assertEqual($this->drupalGetHeader('Content-Type'), 'application/hal+json');
+
+    $this->drupalGet($node_uri);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+    $this->assertEqual($this->drupalGetHeader('Content-Type'), 'text/html; charset=UTF-8');
+    $this->drupalGet($node_uri);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+    $this->assertEqual($this->drupalGetHeader('Content-Type'), 'text/html; charset=UTF-8');
+  }
+
+  /**
+   * Tests support of requests with If-Modified-Since and If-None-Match headers.
+   */
+  public function testConditionalRequests() {
+    $config = $this->config('system.performance');
+    $config->set('cache.page.max_age', 300);
+    $config->save();
+
+    // Fill the cache.
+    $this->drupalGet('');
+    // Verify the page is not printed twice when the cache is cold.
+    $this->assertNoPattern('#<html.*<html#');
+
+    $this->drupalGet('');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
+    $etag = $this->drupalGetHeader('ETag');
+    $last_modified = $this->drupalGetHeader('Last-Modified');
+
+    $this->drupalGet('', [], ['If-Modified-Since' => $last_modified, 'If-None-Match' => $etag]);
+    $this->assertResponse(304, 'Conditional request returned 304 Not Modified.');
+
+    $this->drupalGet('', [], [
+      'If-Modified-Since' => gmdate(DATE_RFC822, strtotime($last_modified)),
+      'If-None-Match' => $etag,
+    ]);
+    $this->assertResponse(304, 'Conditional request with obsolete If-Modified-Since date returned 304 Not Modified.');
+
+    $this->drupalGet('', [], [
+      'If-Modified-Since' => gmdate(DATE_RFC850, strtotime($last_modified)),
+      'If-None-Match' => $etag,
+    ]);
+    $this->assertResponse(304, 'Conditional request with obsolete If-Modified-Since date returned 304 Not Modified.');
+
+    $this->drupalGet('', [], ['If-Modified-Since' => $last_modified, 'If-None-Match' => NULL]);
+    // Verify the page is not printed twice when the cache is warm.
+    $this->assertNoPattern('#<html.*<html#');
+    $this->assertResponse(200, 'Conditional request without If-None-Match returned 200 OK.');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
+
+    $this->drupalGet('', [], [
+      'If-Modified-Since' => gmdate(DateTimePlus::RFC7231, strtotime($last_modified) + 1),
+      'If-None-Match' => $etag,
+    ]);
+    $this->assertResponse(200, 'Conditional request with new a If-Modified-Since date newer than Last-Modified returned 200 OK.');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
+
+    $user = $this->drupalCreateUser();
+    $this->drupalLogin($user);
+    $this->drupalGet('', [], ['If-Modified-Since' => $last_modified, 'If-None-Match' => $etag]);
+    $this->assertResponse(200, 'Conditional request returned 200 OK for authenticated user.');
+    $this->assertFalse($this->drupalGetHeader('X-Drupal-Cache'), 'Absence of Page was not cached.');
+  }
+
+  /**
+   * Tests cache headers.
+   */
+  public function testPageCache() {
+    $config = $this->config('system.performance');
+    $config->set('cache.page.max_age', 300);
+    $config->save();
+
+    // Fill the cache.
+    $this->drupalGet('system-test/set-header', ['query' => ['name' => 'Foo', 'value' => 'bar']]);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS', 'Page was not cached.');
+    $this->assertEqual(strtolower($this->drupalGetHeader('Vary')), 'cookie,accept-encoding', 'Vary header was sent.');
+    // Symfony's Response logic determines a specific order for the subvalues
+    // of the Cache-Control header, even if they are explicitly passed in to
+    // the response header bag in a different order.
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'max-age=300, public', 'Cache-Control header was sent.');
+    $this->assertEqual($this->drupalGetHeader('Expires'), 'Sun, 19 Nov 1978 05:00:00 GMT', 'Expires header was sent.');
+    $this->assertEqual($this->drupalGetHeader('Foo'), 'bar', 'Custom header was sent.');
+
+    // Check cache.
+    $this->drupalGet('system-test/set-header', ['query' => ['name' => 'Foo', 'value' => 'bar']]);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
+    $this->assertEqual(strtolower($this->drupalGetHeader('Vary')), 'cookie,accept-encoding', 'Vary: Cookie header was sent.');
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'max-age=300, public', 'Cache-Control header was sent.');
+    $this->assertEqual($this->drupalGetHeader('Expires'), 'Sun, 19 Nov 1978 05:00:00 GMT', 'Expires header was sent.');
+    $this->assertEqual($this->drupalGetHeader('Foo'), 'bar', 'Custom header was sent.');
+
+    // Check replacing default headers.
+    $this->drupalGet('system-test/set-header', ['query' => ['name' => 'Expires', 'value' => 'Fri, 19 Nov 2008 05:00:00 GMT']]);
+    $this->assertEqual($this->drupalGetHeader('Expires'), 'Fri, 19 Nov 2008 05:00:00 GMT', 'Default header was replaced.');
+    $this->drupalGet('system-test/set-header', ['query' => ['name' => 'Vary', 'value' => 'User-Agent']]);
+    $this->assertEqual(strtolower($this->drupalGetHeader('Vary')), 'user-agent,accept-encoding', 'Default header was replaced.');
+
+    // Check that authenticated users bypass the cache.
+    $user = $this->drupalCreateUser();
+    $this->drupalLogin($user);
+    $this->drupalGet('system-test/set-header', ['query' => ['name' => 'Foo', 'value' => 'bar']]);
+    $this->assertFalse($this->drupalGetHeader('X-Drupal-Cache'), 'Caching was bypassed.');
+    $this->assertTrue(strpos(strtolower($this->drupalGetHeader('Vary')), 'cookie') === FALSE, 'Vary: Cookie header was not sent.');
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'must-revalidate, no-cache, private', 'Cache-Control header was sent.');
+    $this->assertEqual($this->drupalGetHeader('Expires'), 'Sun, 19 Nov 1978 05:00:00 GMT', 'Expires header was sent.');
+    $this->assertEqual($this->drupalGetHeader('Foo'), 'bar', 'Custom header was sent.');
+
+    // Until bubbling of max-age up to the response is supported, verify that
+    // a custom #cache max-age set on an element does not affect page max-age.
+    $this->drupalLogout();
+    $this->drupalGet('system-test/cache_maxage_page');
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'max-age=300, public');
+  }
+
+  /**
+   * Tests the automatic presence of the anonymous role's cache tag.
+   *
+   * The 'user.permissions' cache context ensures that if the permissions for a
+   * role are modified, users are not served stale render cache content. But,
+   * when entire responses are cached in reverse proxies, the value for the
+   * cache context is never calculated, causing the stale response to not be
+   * invalidated. Therefore, when varying by permissions and the current user is
+   * the anonymous user, the cache tag for the 'anonymous' role must be added.
+   *
+   * This test verifies that, and it verifies that it does not happen for other
+   * roles.
+   */
+  public function testPageCacheAnonymousRolePermissions() {
+    $config = $this->config('system.performance');
+    $config->set('cache.page.max_age', 300);
+    $config->save();
+
+    $content_url = Url::fromRoute('system_test.permission_dependent_content');
+    $route_access_url = Url::fromRoute('system_test.permission_dependent_route_access');
+
+    // 1. anonymous user, without permission.
+    $this->drupalGet($content_url);
+    $this->assertText('Permission to pet llamas: no!');
+    $this->assertCacheContext('user.permissions');
+    $this->assertCacheTag('config:user.role.anonymous');
+    $this->drupalGet($route_access_url);
+    $this->assertCacheContext('user.permissions');
+    $this->assertCacheTag('config:user.role.anonymous');
+
+    // 2. anonymous user, with permission.
+    user_role_grant_permissions(RoleInterface::ANONYMOUS_ID, ['pet llamas']);
+    $this->drupalGet($content_url);
+    $this->assertText('Permission to pet llamas: yes!');
+    $this->assertCacheContext('user.permissions');
+    $this->assertCacheTag('config:user.role.anonymous');
+    $this->drupalGet($route_access_url);
+    $this->assertCacheContext('user.permissions');
+    $this->assertCacheTag('config:user.role.anonymous');
+
+    // 3. authenticated user, without permission.
+    $auth_user = $this->drupalCreateUser();
+    $this->drupalLogin($auth_user);
+    $this->drupalGet($content_url);
+    $this->assertText('Permission to pet llamas: no!');
+    $this->assertCacheContext('user.permissions');
+    $this->assertNoCacheTag('config:user.role.authenticated');
+    $this->drupalGet($route_access_url);
+    $this->assertCacheContext('user.permissions');
+    $this->assertNoCacheTag('config:user.role.authenticated');
+
+    // 4. authenticated user, with permission.
+    user_role_grant_permissions(RoleInterface::AUTHENTICATED_ID, ['pet llamas']);
+    $this->drupalGet($content_url);
+    $this->assertText('Permission to pet llamas: yes!');
+    $this->assertCacheContext('user.permissions');
+    $this->assertNoCacheTag('config:user.role.authenticated');
+    $this->drupalGet($route_access_url);
+    $this->assertCacheContext('user.permissions');
+    $this->assertNoCacheTag('config:user.role.authenticated');
+  }
+
+  /**
+   * Tests the 4xx-response cache tag is added and invalidated.
+   */
+  public function testPageCacheAnonymous403404() {
+    $admin_url = Url::fromRoute('system.admin');
+    $invalid_url = 'foo/does_not_exist';
+    $tests = [
+      403 => $admin_url,
+      404 => $invalid_url,
+    ];
+    $cache_ttl_4xx = Settings::get('cache_ttl_4xx', 3600);
+    foreach ($tests as $code => $content_url) {
+      // Anonymous user, without permissions.
+      $this->drupalGet($content_url);
+      $this->assertResponse($code);
+      $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+      $this->assertCacheTag('4xx-response');
+      $this->drupalGet($content_url);
+      $this->assertResponse($code);
+      $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+      $entity_values = [
+        'name' => $this->randomMachineName(),
+        'user_id' => 1,
+        'field_test_text' => [
+          0 => [
+            'value' => $this->randomString(),
+            'format' => 'plain_text',
+          ]
+        ],
+      ];
+      $entity = EntityTest::create($entity_values);
+      $entity->save();
+      // Saving an entity clears 4xx cache tag.
+      $this->drupalGet($content_url);
+      $this->assertResponse($code);
+      $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+      $this->drupalGet($content_url);
+      $this->assertResponse($code);
+      $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT');
+      // Rebuilding the router should invalidate the 4xx cache tag.
+      $this->container->get('router.builder')->rebuild();
+      $this->drupalGet($content_url);
+      $this->assertResponse($code);
+      $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+
+      // Ensure the 'expire' field on the cache entry uses cache_ttl_4xx.
+      $cache_item = \Drupal::service('cache.page')->get($this->getUrl() . ':html');
+      $difference = $cache_item->expire - (int) $cache_item->created;
+      // Given that a second might have passed we cannot be sure that
+      // $difference will exactly equal the default cache_ttl_4xx setting.
+      // Account for any timing difference or rounding errors by ensuring the
+      // value is within 10 seconds.
+      $this->assertTrue(
+        $difference > $cache_ttl_4xx - 10 &&
+        $difference < $cache_ttl_4xx + 10,
+        "The cache entry expiry time uses the cache_ttl_4xx setting. Expire: {$cache_item->expire} Created: {$cache_item->created}"
+      );
+    }
+
+    // Disable 403 and 404 caching.
+    $settings['settings']['cache_ttl_4xx'] = (object) [
+      'value' => 0,
+      'required' => TRUE,
+    ];
+    $this->writeSettings($settings);
+    \Drupal::service('cache.page')->deleteAll();
+
+    foreach ($tests as $code => $content_url) {
+      // Getting the 404 page twice should still result in a cache miss.
+      $this->drupalGet($content_url);
+      $this->drupalGet($content_url);
+      $this->assertResponse($code);
+      $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS');
+    }
+  }
+
+  /**
+   * Tests the omit_vary_cookie setting.
+   */
+  public function testPageCacheWithoutVaryCookie() {
+    $config = $this->config('system.performance');
+    $config->set('cache.page.max_age', 300);
+    $config->save();
+
+    $settings['settings']['omit_vary_cookie'] = (object) [
+      'value' => TRUE,
+      'required' => TRUE,
+    ];
+    $this->writeSettings($settings);
+
+    // Fill the cache.
+    $this->drupalGet('');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS', 'Page was not cached.');
+    $this->assertTrue(strpos($this->drupalGetHeader('Vary'), 'Cookie') === FALSE, 'Vary: Cookie header was not sent.');
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'max-age=300, public', 'Cache-Control header was sent.');
+
+    // Check cache.
+    $this->drupalGet('');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
+    $this->assertTrue(strpos($this->drupalGetHeader('Vary'), 'Cookie') === FALSE, 'Vary: Cookie header was not sent.');
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'max-age=300, public', 'Cache-Control header was sent.');
+  }
+
+  /**
+   * Test the setting of forms to be immutable.
+   */
+  public function testFormImmutability() {
+    // Install the module that provides the test form.
+    $this->container->get('module_installer')
+      ->install(['page_cache_form_test']);
+    // Uninstall the page_cache module to verify that form is immutable
+    // regardless of the internal page cache module.
+    $this->container->get('module_installer')->uninstall(['page_cache']);
+    \Drupal::service('router.builder')->rebuild();
+
+    $this->drupalGet('page_cache_form_test_immutability');
+
+    $this->assertText("Immutable: TRUE", "Form is immutable.");
+
+    // The immutable flag is set unconditionally by system_form_alter(), set
+    // a flag to tell page_cache_form_test_module_implements_alter() to disable
+    // that implementation.
+    \Drupal::state()->set('page_cache_bypass_form_immutability', TRUE);
+    \Drupal::moduleHandler()->resetImplementations();
+    Cache::invalidateTags(['rendered']);
+
+    $this->drupalGet('page_cache_form_test_immutability');
+
+    $this->assertText("Immutable: FALSE", "Form is not immutable,");
+  }
+
+  /**
+   * Tests cacheability of a CacheableResponse.
+   *
+   * Tests the difference between having a controller return a plain Symfony
+   * Response object versus returning a Response object that implements the
+   * CacheableResponseInterface.
+   */
+  public function testCacheableResponseResponses() {
+    $config = $this->config('system.performance');
+    $config->set('cache.page.max_age', 300);
+    $config->save();
+
+    // GET a URL, which would be marked as a cache miss if it were cacheable.
+    $this->drupalGet('/system-test/respond-reponse');
+    $this->assertFalse($this->drupalGetHeader('X-Drupal-Cache'), 'Drupal page cache header not found.');
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'must-revalidate, no-cache, private', 'Cache-Control header was sent');
+
+    // GET it again, verify it's still not cached.
+    $this->drupalGet('/system-test/respond-reponse');
+    $this->assertFalse($this->drupalGetHeader('X-Drupal-Cache'), 'Drupal page cache header not found.');
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'must-revalidate, no-cache, private', 'Cache-Control header was sent');
+
+    // GET a URL, which would be marked as a cache miss if it were cacheable.
+    $this->drupalGet('/system-test/respond-public-response');
+    $this->assertFalse($this->drupalGetHeader('X-Drupal-Cache'), 'Drupal page cache header not found.');
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'max-age=60, public', 'Cache-Control header was sent');
+
+    // GET it again, verify it's still not cached.
+    $this->drupalGet('/system-test/respond-public-response');
+    $this->assertFalse($this->drupalGetHeader('X-Drupal-Cache'), 'Drupal page cache header not found.');
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'max-age=60, public', 'Cache-Control header was sent');
+
+    // GET a URL, which should be marked as a cache miss.
+    $this->drupalGet('/system-test/respond-cacheable-reponse');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS', 'Page was not cached.');
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'max-age=300, public', 'Cache-Control header was sent.');
+
+    // GET it again, it should now be a cache hit.
+    $this->drupalGet('/system-test/respond-cacheable-reponse');
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
+    $this->assertEqual($this->drupalGetHeader('Cache-Control'), 'max-age=300, public', 'Cache-Control header was sent.');
+
+    // Uninstall page cache. This should flush all caches so the next call to a
+    // previously cached page should be a miss now.
+    $this->container->get('module_installer')
+      ->uninstall(['page_cache']);
+
+    // GET a URL that was cached by Page Cache before, it should not be now.
+    $this->drupalGet('/respond-cacheable-reponse');
+    $this->assertFalse($this->drupalGetHeader('X-Drupal-Cache'), 'Drupal page cache header not found.');
+  }
+
+  /**
+   * Tests that HEAD requests are treated the same as GET requests.
+   */
+  public function testHead() {
+    /** @var \GuzzleHttp\ClientInterface $client */
+    $client = $this->getSession()->getDriver()->getClient()->getClient();
+
+    // GET, then HEAD.
+    $url_a = $this->buildUrl('system-test/set-header', ['query' => ['name' => 'Foo', 'value' => 'bar']]);
+    $response_body = $this->drupalGet($url_a);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS', 'Page was not cached.');
+    $this->assertEqual($this->drupalGetHeader('Foo'), 'bar', 'Custom header was sent.');
+    $this->assertEqual('The following header was set: <em class="placeholder">Foo</em>: <em class="placeholder">bar</em>', $response_body);
+    $response = $client->request('HEAD', $url_a);
+    $this->assertEqual($response->getHeaderLine('X-Drupal-Cache'), 'HIT', 'Page was cached.');
+    $this->assertEqual($response->getHeaderLine('Foo'), 'bar', 'Custom header was sent.');
+    $this->assertEqual('', $response->getBody()->getContents());
+
+    // HEAD, then GET.
+    $url_b = $this->buildUrl('system-test/set-header', ['query' => ['name' => 'Foo', 'value' => 'baz']]);
+    $response = $client->request('HEAD', $url_b);
+    $this->assertEqual($response->getHeaderLine('X-Drupal-Cache'), 'MISS', 'Page was not cached.');
+    $this->assertEqual($response->getHeaderLine('Foo'), 'baz', 'Custom header was sent.');
+    $this->assertEqual('', $response->getBody()->getContents());
+    $response_body = $this->drupalGet($url_b);
+    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
+    $this->assertEqual($this->drupalGetHeader('Foo'), 'baz', 'Custom header was sent.');
+    $this->assertEqual('The following header was set: <em class="placeholder">Foo</em>: <em class="placeholder">baz</em>', $response_body);
+  }
+
+  /**
+   * Test a cacheable response with custom cache control.
+   */
+  public function testCacheableWithCustomCacheControl() {
+    $config = $this->config('system.performance');
+    $config->set('cache.page.max_age', 300);
+    $config->save();
+
+    $this->drupalGet('/system-test/custom-cache-control');
+    $this->assertResponse(200);
+    $this->assertHeader('Cache-Control', 'bar, private');
+  }
+
+  /**
+   * Test that URLs are cached in a not normalized form.
+   */
+  public function testNoUrlNormalization() {
+
+    // Use absolute URLs to avoid any processing.
+    $url = Url::fromRoute('<front>')->setAbsolute()->toString();
+
+    // In each test, the first array value is raw URL, the second one is the
+    // possible normalized URL.
+    $tests = [
+      [
+        $url . '?z=z&a=a',
+        $url . '?a=a&z=z',
+      ],
+      [
+        $url . '?',
+        $url . '',
+      ],
+      [
+        $url . '?a=b+c',
+        $url . '?a=b%20c',
+      ],
+    ];
+
+    foreach ($tests as list($url_raw, $url_normalized)) {
+      // Initialize cache on raw URL.
+      $headers = $this->getHeaders($url_raw);
+      $this->assertEquals('MISS', $headers['X-Drupal-Cache']);
+
+      // Ensure cache was set.
+      $headers = $this->getHeaders($url_raw);
+      $this->assertEquals('HIT', $headers['X-Drupal-Cache'], "Cache was set for {$url_raw} URL.");
+
+      // Check if the normalized URL is not cached.
+      $headers = $this->getHeaders($url_normalized);
+      $this->assertEquals('MISS', $headers['X-Drupal-Cache'], "Cache is missing for {$url_normalized} URL.");
+    }
+  }
+
+  /**
+   * Retrieves only the headers for an absolute path.
+   *
+   * Executes a cURL request without any modifications to the given URL.
+   * Note that Guzzle always normalizes URLs which prevents testing all
+   * possible edge cases.
+   *
+   * @param string $url
+   *   URL to request.
+   *
+   * @return array
+   *   Array of headers.
+   */
+  protected function getHeaders($url) {
+    $ch = curl_init();
+    curl_setopt($ch, CURLOPT_URL, $url);
+    curl_setopt($ch, CURLOPT_HEADER, TRUE);
+    curl_setopt($ch, CURLOPT_NOBODY, TRUE);
+    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
+    curl_setopt($ch, CURLOPT_USERAGENT, drupal_generate_test_ua($this->databasePrefix));
+    $output = curl_exec($ch);
+    curl_close($ch);
+
+    $headers = [];
+    foreach (explode("\n", $output) as $header) {
+      if (strpos($header, ':')) {
+        list($key, $value) = explode(':', $header, 2);
+        $headers[trim($key)] = trim($value);
+      }
+    }
+
+    return $headers;
+  }
+
+}