www.aleph1.co.uk Git - yaffs-website/blob - web/core/modules/big_pipe/src/Tests/BigPipeTest.php

   1 <?php
   2
   3 namespace Drupal\big_pipe\Tests;
   4
   5 use Drupal\big_pipe\Render\Placeholder\BigPipeStrategy;
   6 use Drupal\big_pipe\Render\BigPipe;
   7 use Drupal\Component\Serialization\Json;
   8 use Drupal\Component\Utility\Html;
   9 use Drupal\Core\Logger\RfcLogLevel;
  10 use Drupal\Core\Url;
  11 use Drupal\simpletest\WebTestBase;
  12
  13 /**
  14  * Tests BigPipe's no-JS detection & response delivery (with and without JS).
  15  *
  16  * Covers:
  17  * - big_pipe_page_attachments()
  18  * - \Drupal\big_pipe\Controller\BigPipeController
  19  * - \Drupal\big_pipe\EventSubscriber\HtmlResponseBigPipeSubscriber
  20  * - \Drupal\big_pipe\Render\BigPipe
  21  *
  22  * @group big_pipe
  23  */
  24 class BigPipeTest extends WebTestBase {
  25
  26   /**
  27    * Modules to enable.
  28    *
  29    * @var array
  30    */
  31   public static $modules = ['big_pipe', 'big_pipe_test', 'dblog'];
  32
  33   /**
  34    * {@inheritdoc}
  35    */
  36   protected $dumpHeaders = TRUE;
  37
  38   /**
  39    * {@inheritdoc}
  40    */
  41   protected function setUp() {
  42     parent::setUp();
  43
  44     // Ignore the <meta> refresh that big_pipe.module sets. It causes a redirect
  45     // to a page that sets another cookie, which causes WebTestBase to lose the
  46     // session cookie. To avoid this problem, tests should first call
  47     // drupalGet() and then call checkForMetaRefresh() manually, and then reset
  48     // $this->maximumMetaRefreshCount and $this->metaRefreshCount.
  49     // @see doMetaRefresh()
  50     $this->maximumMetaRefreshCount = 0;
  51   }
  52
  53   /**
  54    * Performs a single <meta> refresh explicitly.
  55    *
  56    * This test disables the automatic <meta> refresh checking, each time it is
  57    * desired that this runs, a test case must explicitly call this.
  58    *
  59    * @see setUp()
  60    */
  61   protected function performMetaRefresh() {
  62     $this->maximumMetaRefreshCount = 1;
  63     $this->checkForMetaRefresh();
  64     $this->maximumMetaRefreshCount = 0;
  65     $this->metaRefreshCount = 0;
  66   }
  67
  68   /**
  69    * Tests BigPipe's no-JS detection.
  70    *
  71    * Covers:
  72    * - big_pipe_page_attachments()
  73    * - \Drupal\big_pipe\Controller\BigPipeController
  74    */
  75   public function testNoJsDetection() {
  76     $no_js_to_js_markup = '<script>document.cookie = "' . BigPipeStrategy::NOJS_COOKIE . '=1; path=/; expires=Thu, 01 Jan 1970 00:00:00 GMT"</script>';
  77
  78     // 1. No session (anonymous).
  79     $this->drupalGet(Url::fromRoute('<front>'));
  80     $this->assertSessionCookieExists(FALSE);
  81     $this->assertBigPipeNoJsCookieExists(FALSE);
  82     $this->assertNoRaw('<noscript><meta http-equiv="Refresh" content="0; URL=');
  83     $this->assertNoRaw($no_js_to_js_markup);
  84
  85     // 2. Session (authenticated).
  86     $this->drupalLogin($this->rootUser);
  87     $this->assertSessionCookieExists(TRUE);
  88     $this->assertBigPipeNoJsCookieExists(FALSE);
  89     $this->assertRaw('<noscript><meta http-equiv="Refresh" content="0; URL=' . base_path() . 'big_pipe/no-js?destination=' . base_path() . 'user/1" />' . "\n" . '</noscript>');
  90     $this->assertNoRaw($no_js_to_js_markup);
  91     $this->assertBigPipeNoJsMetaRefreshRedirect();
  92     $this->assertBigPipeNoJsCookieExists(TRUE);
  93     $this->assertNoRaw('<noscript><meta http-equiv="Refresh" content="0; URL=');
  94     $this->assertRaw($no_js_to_js_markup);
  95     $this->drupalLogout();
  96
  97     // Close the prior connection and remove the collected state.
  98     $this->curlClose();
  99     $this->curlCookies = [];
 100     $this->cookies = [];
 101
 102     // 3. Session (anonymous).
 103     $this->drupalGet(Url::fromRoute('user.login', [], ['query' => ['trigger_session' => 1]]));
 104     $this->drupalGet(Url::fromRoute('user.login'));
 105     $this->assertSessionCookieExists(TRUE);
 106     $this->assertBigPipeNoJsCookieExists(FALSE);
 107     $this->assertRaw('<noscript><meta http-equiv="Refresh" content="0; URL=' . base_path() . 'big_pipe/no-js?destination=' . base_path() . 'user/login" />' . "\n" . '</noscript>');
 108     $this->assertNoRaw($no_js_to_js_markup);
 109     $this->assertBigPipeNoJsMetaRefreshRedirect();
 110     $this->assertBigPipeNoJsCookieExists(TRUE);
 111     $this->assertNoRaw('<noscript><meta http-equiv="Refresh" content="0; URL=');
 112     $this->assertRaw($no_js_to_js_markup);
 113
 114     // Close the prior connection and remove the collected state.
 115     $this->curlClose();
 116     $this->curlCookies = [];
 117     $this->cookies = [];
 118
 119     // Edge case: route with '_no_big_pipe' option.
 120     $this->drupalGet(Url::fromRoute('no_big_pipe'));
 121     $this->assertSessionCookieExists(FALSE);
 122     $this->assertBigPipeNoJsCookieExists(FALSE);
 123     $this->assertNoRaw('<noscript><meta http-equiv="Refresh" content="0; URL=');
 124     $this->assertNoRaw($no_js_to_js_markup);
 125     $this->drupalLogin($this->rootUser);
 126     $this->drupalGet(Url::fromRoute('no_big_pipe'));
 127     $this->assertSessionCookieExists(TRUE);
 128     $this->assertBigPipeNoJsCookieExists(FALSE);
 129     $this->assertNoRaw('<noscript><meta http-equiv="Refresh" content="0; URL=');
 130     $this->assertNoRaw($no_js_to_js_markup);
 131   }
 132
 133   /**
 134    * Tests BigPipe-delivered HTML responses when JavaScript is enabled.
 135    *
 136    * Covers:
 137    * - \Drupal\big_pipe\EventSubscriber\HtmlResponseBigPipeSubscriber
 138    * - \Drupal\big_pipe\Render\BigPipe
 139    * - \Drupal\big_pipe\Render\BigPipe::sendPlaceholders()
 140    *
 141    * @see \Drupal\big_pipe\Tests\BigPipePlaceholderTestCases
 142    */
 143   public function testBigPipe() {
 144     // Simulate production.
 145     $this->config('system.logging')->set('error_level', ERROR_REPORTING_HIDE)->save();
 146
 147     $this->drupalLogin($this->rootUser);
 148     $this->assertSessionCookieExists(TRUE);
 149     $this->assertBigPipeNoJsCookieExists(FALSE);
 150
 151     $log_count = db_query('SELECT COUNT(*) FROM {watchdog}')->fetchField();
 152
 153     // By not calling performMetaRefresh() here, we simulate JavaScript being
 154     // enabled, because as far as the BigPipe module is concerned, JavaScript is
 155     // enabled in the browser as long as the BigPipe no-JS cookie is *not* set.
 156     // @see setUp()
 157     // @see performMetaRefresh()
 158
 159     $this->drupalGet(Url::fromRoute('big_pipe_test'));
 160     $this->assertBigPipeResponseHeadersPresent();
 161     $this->assertNoCacheTag('cache_tag_set_in_lazy_builder');
 162
 163     $this->setCsrfTokenSeedInTestEnvironment();
 164     $cases = $this->getTestCases();
 165     $this->assertBigPipeNoJsPlaceholders([
 166       $cases['edge_case__invalid_html']->bigPipeNoJsPlaceholder     => $cases['edge_case__invalid_html']->embeddedHtmlResponse,
 167       $cases['html_attribute_value']->bigPipeNoJsPlaceholder        => $cases['html_attribute_value']->embeddedHtmlResponse,
 168       $cases['html_attribute_value_subset']->bigPipeNoJsPlaceholder => $cases['html_attribute_value_subset']->embeddedHtmlResponse,
 169     ]);
 170     $this->assertBigPipePlaceholders([
 171       $cases['html']->bigPipePlaceholderId                             => Json::encode($cases['html']->embeddedAjaxResponseCommands),
 172       $cases['edge_case__html_non_lazy_builder']->bigPipePlaceholderId => Json::encode($cases['edge_case__html_non_lazy_builder']->embeddedAjaxResponseCommands),
 173       $cases['exception__lazy_builder']->bigPipePlaceholderId          => NULL,
 174       $cases['exception__embedded_response']->bigPipePlaceholderId     => NULL,
 175     ], [
 176       0 => $cases['edge_case__html_non_lazy_builder']->bigPipePlaceholderId,
 177       // The 'html' case contains the 'status messages' placeholder, which is
 178       // always rendered last.
 179       1 => $cases['html']->bigPipePlaceholderId,
 180     ]);
 181
 182     $this->assertRaw('</body>', 'Closing body tag present.');
 183
 184     $this->pass('Verifying BigPipe assets are present…', 'Debug');
 185     $this->assertFalse(empty($this->getDrupalSettings()), 'drupalSettings present.');
 186     $this->assertTrue(in_array('big_pipe/big_pipe', explode(',', $this->getDrupalSettings()['ajaxPageState']['libraries'])), 'BigPipe asset library is present.');
 187
 188     // Verify that the two expected exceptions are logged as errors.
 189     $this->assertEqual($log_count + 2, db_query('SELECT COUNT(*) FROM {watchdog}')->fetchField(), 'Two new watchdog entries.');
 190     $records = db_query('SELECT * FROM {watchdog} ORDER BY wid DESC LIMIT 2')->fetchAll();
 191     $this->assertEqual(RfcLogLevel::ERROR, $records[0]->severity);
 192     $this->assertTrue(FALSE !== strpos((string) unserialize($records[0]->variables)['@message'], 'Oh noes!'));
 193     $this->assertEqual(RfcLogLevel::ERROR, $records[1]->severity);
 194     $this->assertTrue(FALSE !== strpos((string) unserialize($records[1]->variables)['@message'], 'You are not allowed to say llamas are not cool!'));
 195
 196     // Verify that 4xx responses work fine. (4xx responses are handled by
 197     // subrequests to a route pointing to a controller with the desired output.)
 198     $this->drupalGet(Url::fromUri('base:non-existing-path'));
 199
 200     // Simulate development.
 201     $this->pass('Verifying BigPipe provides useful error output when an error occurs while rendering a placeholder if verbose error logging is enabled.', 'Debug');
 202     $this->config('system.logging')->set('error_level', ERROR_REPORTING_DISPLAY_VERBOSE)->save();
 203     $this->drupalGet(Url::fromRoute('big_pipe_test'));
 204     // The 'edge_case__html_exception' case throws an exception.
 205     $this->assertRaw('The website encountered an unexpected error. Please try again later');
 206     $this->assertRaw('You are not allowed to say llamas are not cool!');
 207     $this->assertNoRaw(BigPipe::STOP_SIGNAL, 'BigPipe stop signal absent: error occurred before then.');
 208     $this->assertNoRaw('</body>', 'Closing body tag absent: error occurred before then.');
 209     // The exception is expected. Do not interpret it as a test failure.
 210     unlink(\Drupal::root() . '/' . $this->siteDirectory . '/error.log');
 211   }
 212
 213   /**
 214    * Tests BigPipe-delivered HTML responses when JavaScript is disabled.
 215    *
 216    * Covers:
 217    * - \Drupal\big_pipe\EventSubscriber\HtmlResponseBigPipeSubscriber
 218    * - \Drupal\big_pipe\Render\BigPipe
 219    * - \Drupal\big_pipe\Render\BigPipe::sendNoJsPlaceholders()
 220    *
 221    * @see \Drupal\big_pipe\Tests\BigPipePlaceholderTestCases
 222    */
 223   public function testBigPipeNoJs() {
 224     // Simulate production.
 225     $this->config('system.logging')->set('error_level', ERROR_REPORTING_HIDE)->save();
 226
 227     $this->drupalLogin($this->rootUser);
 228     $this->assertSessionCookieExists(TRUE);
 229     $this->assertBigPipeNoJsCookieExists(FALSE);
 230
 231     // By calling performMetaRefresh() here, we simulate JavaScript being
 232     // disabled, because as far as the BigPipe module is concerned, it is
 233     // enabled in the browser when the BigPipe no-JS cookie is set.
 234     // @see setUp()
 235     // @see performMetaRefresh()
 236     $this->performMetaRefresh();
 237     $this->assertBigPipeNoJsCookieExists(TRUE);
 238
 239     $this->drupalGet(Url::fromRoute('big_pipe_test'));
 240     $this->assertBigPipeResponseHeadersPresent();
 241     $this->assertNoCacheTag('cache_tag_set_in_lazy_builder');
 242
 243     $this->setCsrfTokenSeedInTestEnvironment();
 244     $cases = $this->getTestCases();
 245     $this->assertBigPipeNoJsPlaceholders([
 246       $cases['edge_case__invalid_html']->bigPipeNoJsPlaceholder           => $cases['edge_case__invalid_html']->embeddedHtmlResponse,
 247       $cases['html_attribute_value']->bigPipeNoJsPlaceholder              => $cases['html_attribute_value']->embeddedHtmlResponse,
 248       $cases['html_attribute_value_subset']->bigPipeNoJsPlaceholder       => $cases['html_attribute_value_subset']->embeddedHtmlResponse,
 249       $cases['html']->bigPipeNoJsPlaceholder                              => $cases['html']->embeddedHtmlResponse,
 250       $cases['edge_case__html_non_lazy_builder']->bigPipeNoJsPlaceholder  => $cases['edge_case__html_non_lazy_builder']->embeddedHtmlResponse,
 251       $cases['exception__lazy_builder']->bigPipePlaceholderId             => NULL,
 252       $cases['exception__embedded_response']->bigPipePlaceholderId        => NULL,
 253     ]);
 254
 255     $this->pass('Verifying there are no BigPipe placeholders & replacements…', 'Debug');
 256     $this->assertEqual('<none>', $this->drupalGetHeader('BigPipe-Test-Placeholders'));
 257     $this->pass('Verifying BigPipe start/stop signals are absent…', 'Debug');
 258     $this->assertNoRaw(BigPipe::START_SIGNAL, 'BigPipe start signal absent.');
 259     $this->assertNoRaw(BigPipe::STOP_SIGNAL, 'BigPipe stop signal absent.');
 260
 261     $this->pass('Verifying BigPipe assets are absent…', 'Debug');
 262     $this->assertTrue(!isset($this->getDrupalSettings()['bigPipePlaceholderIds']) && empty($this->getDrupalSettings()['ajaxPageState']), 'BigPipe drupalSettings and BigPipe asset library absent.');
 263     $this->assertRaw('</body>', 'Closing body tag present.');
 264
 265     // Verify that 4xx responses work fine. (4xx responses are handled by
 266     // subrequests to a route pointing to a controller with the desired output.)
 267     $this->drupalGet(Url::fromUri('base:non-existing-path'));
 268
 269     // Simulate development.
 270     $this->pass('Verifying BigPipe provides useful error output when an error occurs while rendering a placeholder if verbose error logging is enabled.', 'Debug');
 271     $this->config('system.logging')->set('error_level', ERROR_REPORTING_DISPLAY_VERBOSE)->save();
 272     $this->drupalGet(Url::fromRoute('big_pipe_test'));
 273     // The 'edge_case__html_exception' case throws an exception.
 274     $this->assertRaw('The website encountered an unexpected error. Please try again later');
 275     $this->assertRaw('You are not allowed to say llamas are not cool!');
 276     $this->assertNoRaw('</body>', 'Closing body tag absent: error occurred before then.');
 277     // The exception is expected. Do not interpret it as a test failure.
 278     unlink(\Drupal::root() . '/' . $this->siteDirectory . '/error.log');
 279   }
 280
 281   /**
 282    * Tests BigPipe with a multi-occurrence placeholder.
 283    */
 284   public function testBigPipeMultiOccurrencePlaceholders() {
 285     $this->drupalLogin($this->rootUser);
 286     $this->assertSessionCookieExists(TRUE);
 287     $this->assertBigPipeNoJsCookieExists(FALSE);
 288
 289     // By not calling performMetaRefresh() here, we simulate JavaScript being
 290     // enabled, because as far as the BigPipe module is concerned, JavaScript is
 291     // enabled in the browser as long as the BigPipe no-JS cookie is *not* set.
 292     // @see setUp()
 293     // @see performMetaRefresh()
 294
 295     $this->drupalGet(Url::fromRoute('big_pipe_test_multi_occurrence'));
 296     $big_pipe_placeholder_id = 'callback=Drupal%5CCore%5CRender%5CElement%5CStatusMessages%3A%3ArenderMessages&amp;args%5B0%5D&amp;token=_HAdUpwWmet0TOTe2PSiJuMntExoshbm1kh2wQzzzAA';
 297     $expected_placeholder_replacement = '<script type="application/vnd.drupal-ajax" data-big-pipe-replacement-for-placeholder-with-id="' . $big_pipe_placeholder_id . '">';
 298     $this->assertRaw('The count is 1.');
 299     $this->assertNoRaw('The count is 2.');
 300     $this->assertNoRaw('The count is 3.');
 301     $raw_content = $this->getRawContent();
 302     $this->assertTrue(substr_count($raw_content, $expected_placeholder_replacement) == 1, 'Only one placeholder replacement was found for the duplicate #lazy_builder arrays.');
 303
 304     // By calling performMetaRefresh() here, we simulate JavaScript being
 305     // disabled, because as far as the BigPipe module is concerned, it is
 306     // enabled in the browser when the BigPipe no-JS cookie is set.
 307     // @see setUp()
 308     // @see performMetaRefresh()
 309     $this->performMetaRefresh();
 310     $this->assertBigPipeNoJsCookieExists(TRUE);
 311     $this->drupalGet(Url::fromRoute('big_pipe_test_multi_occurrence'));
 312     $this->assertRaw('The count is 1.');
 313     $this->assertNoRaw('The count is 2.');
 314     $this->assertNoRaw('The count is 3.');
 315   }
 316
 317   protected function assertBigPipeResponseHeadersPresent() {
 318     $this->pass('Verifying BigPipe response headers…', 'Debug');
 319     $this->assertTrue(FALSE !== strpos($this->drupalGetHeader('Cache-Control'), 'private'), 'Cache-Control header set to "private".');
 320     $this->assertEqual('no-store, content="BigPipe/1.0"', $this->drupalGetHeader('Surrogate-Control'));
 321     $this->assertEqual('no', $this->drupalGetHeader('X-Accel-Buffering'));
 322   }
 323
 324   /**
 325    * Asserts expected BigPipe no-JS placeholders are present and replaced.
 326    *
 327    * @param array $expected_big_pipe_nojs_placeholders
 328    *   Keys: BigPipe no-JS placeholder markup. Values: expected replacement
 329    *   markup.
 330    */
 331   protected function assertBigPipeNoJsPlaceholders(array $expected_big_pipe_nojs_placeholders) {
 332     $this->pass('Verifying BigPipe no-JS placeholders & replacements…', 'Debug');
 333     $this->assertSetsEqual(array_keys($expected_big_pipe_nojs_placeholders), array_map('rawurldecode', explode(' ', $this->drupalGetHeader('BigPipe-Test-No-Js-Placeholders'))));
 334     foreach ($expected_big_pipe_nojs_placeholders as $big_pipe_nojs_placeholder => $expected_replacement) {
 335       $this->pass('Checking whether the replacement for the BigPipe no-JS placeholder "' . $big_pipe_nojs_placeholder . '" is present:');
 336       $this->assertNoRaw($big_pipe_nojs_placeholder);
 337       if ($expected_replacement !== NULL) {
 338         $this->assertRaw($expected_replacement);
 339       }
 340     }
 341   }
 342
 343   /**
 344    * Asserts expected BigPipe placeholders are present and replaced.
 345    *
 346    * @param array $expected_big_pipe_placeholders
 347    *   Keys: BigPipe placeholder IDs. Values: expected AJAX response.
 348    * @param array $expected_big_pipe_placeholder_stream_order
 349    *   Keys: BigPipe placeholder IDs. Values: expected AJAX response. Keys are
 350    *   defined in the order that they are expected to be rendered & streamed.
 351    */
 352   protected function assertBigPipePlaceholders(array $expected_big_pipe_placeholders, array $expected_big_pipe_placeholder_stream_order) {
 353     $this->pass('Verifying BigPipe placeholders & replacements…', 'Debug');
 354     $this->assertSetsEqual(array_keys($expected_big_pipe_placeholders), explode(' ', $this->drupalGetHeader('BigPipe-Test-Placeholders')));
 355     $placeholder_positions = [];
 356     $placeholder_replacement_positions = [];
 357     foreach ($expected_big_pipe_placeholders as $big_pipe_placeholder_id => $expected_ajax_response) {
 358       $this->pass('BigPipe placeholder: ' . $big_pipe_placeholder_id, 'Debug');
 359       // Verify expected placeholder.
 360       $expected_placeholder_html = '<span data-big-pipe-placeholder-id="' . $big_pipe_placeholder_id . '"></span>';
 361       $this->assertRaw($expected_placeholder_html, 'BigPipe placeholder for placeholder ID "' . $big_pipe_placeholder_id . '" found.');
 362       $pos = strpos($this->getRawContent(), $expected_placeholder_html);
 363       $placeholder_positions[$pos] = $big_pipe_placeholder_id;
 364       // Verify expected placeholder replacement.
 365       $expected_placeholder_replacement = '<script type="application/vnd.drupal-ajax" data-big-pipe-replacement-for-placeholder-with-id="' . $big_pipe_placeholder_id . '">';
 366       $result = $this->xpath('//script[@data-big-pipe-replacement-for-placeholder-with-id=:id]', [':id' => Html::decodeEntities($big_pipe_placeholder_id)]);
 367       if ($expected_ajax_response === NULL) {
 368         $this->assertEqual(0, count($result));
 369         $this->assertNoRaw($expected_placeholder_replacement);
 370         continue;
 371       }
 372       $this->assertEqual($expected_ajax_response, trim((string) $result[0]));
 373       $this->assertRaw($expected_placeholder_replacement);
 374       $pos = strpos($this->getRawContent(), $expected_placeholder_replacement);
 375       $placeholder_replacement_positions[$pos] = $big_pipe_placeholder_id;
 376     }
 377     ksort($placeholder_positions, SORT_NUMERIC);
 378     $this->assertEqual(array_keys($expected_big_pipe_placeholders), array_values($placeholder_positions));
 379     $placeholders = array_map(function(\SimpleXMLElement $element) { return (string) $element['data-big-pipe-placeholder-id']; }, $this->cssSelect('[data-big-pipe-placeholder-id]'));
 380     $this->assertEqual(count($expected_big_pipe_placeholders), count(array_unique($placeholders)));
 381     $expected_big_pipe_placeholders_with_replacements = [];
 382     foreach ($expected_big_pipe_placeholder_stream_order as $big_pipe_placeholder_id) {
 383       $expected_big_pipe_placeholders_with_replacements[$big_pipe_placeholder_id] = $expected_big_pipe_placeholders[$big_pipe_placeholder_id];
 384     }
 385     $this->assertEqual($expected_big_pipe_placeholders_with_replacements, array_filter($expected_big_pipe_placeholders));
 386     $this->assertSetsEqual(array_keys($expected_big_pipe_placeholders_with_replacements), array_values($placeholder_replacement_positions));
 387     $this->assertEqual(count($expected_big_pipe_placeholders_with_replacements), preg_match_all('/' . preg_quote('<script type="application/vnd.drupal-ajax" data-big-pipe-replacement-for-placeholder-with-id="', '/') . '/', $this->getRawContent()));
 388
 389     $this->pass('Verifying BigPipe start/stop signals…', 'Debug');
 390     $this->assertRaw(BigPipe::START_SIGNAL, 'BigPipe start signal present.');
 391     $this->assertRaw(BigPipe::STOP_SIGNAL, 'BigPipe stop signal present.');
 392     $start_signal_position = strpos($this->getRawContent(), BigPipe::START_SIGNAL);
 393     $stop_signal_position = strpos($this->getRawContent(), BigPipe::STOP_SIGNAL);
 394     $this->assertTrue($start_signal_position < $stop_signal_position, 'BigPipe start signal appears before stop signal.');
 395
 396     $this->pass('Verifying BigPipe placeholder replacements and start/stop signals were streamed in the correct order…', 'Debug');
 397     $expected_stream_order = array_keys($expected_big_pipe_placeholders_with_replacements);
 398     array_unshift($expected_stream_order, BigPipe::START_SIGNAL);
 399     array_push($expected_stream_order, BigPipe::STOP_SIGNAL);
 400     $actual_stream_order = $placeholder_replacement_positions + [
 401         $start_signal_position => BigPipe::START_SIGNAL,
 402         $stop_signal_position => BigPipe::STOP_SIGNAL,
 403       ];
 404     ksort($actual_stream_order, SORT_NUMERIC);
 405     $this->assertEqual($expected_stream_order, array_values($actual_stream_order));
 406   }
 407
 408   /**
 409    * Ensures CSRF tokens can be generated for the current user's session.
 410    */
 411   protected function setCsrfTokenSeedInTestEnvironment() {
 412     $session_data = $this->container->get('session_handler.write_safe')->read($this->cookies[$this->getSessionName()]['value']);
 413     $csrf_token_seed = unserialize(explode('_sf2_meta|', $session_data)[1])['s'];
 414     $this->container->get('session_manager.metadata_bag')->setCsrfTokenSeed($csrf_token_seed);
 415   }
 416
 417   /**
 418    * @return \Drupal\big_pipe\Tests\BigPipePlaceholderTestCase[]
 419    */
 420   protected function getTestCases($has_session = TRUE) {
 421     return BigPipePlaceholderTestCases::cases($this->container, $this->rootUser);
 422   }
 423
 424   /**
 425    * Asserts whether arrays A and B are equal, when treated as sets.
 426    */
 427   protected function assertSetsEqual(array $a, array $b) {
 428     return count($a) == count($b) && !array_diff_assoc($a, $b);
 429   }
 430
 431   /**
 432    * Asserts whether a BigPipe no-JS cookie exists or not.
 433    */
 434   protected function assertBigPipeNoJsCookieExists($expected) {
 435     $this->assertCookieExists('big_pipe_nojs', $expected, 'BigPipe no-JS');
 436   }
 437
 438   /**
 439    * Asserts whether a session cookie exists or not.
 440    */
 441   protected function assertSessionCookieExists($expected) {
 442     $this->assertCookieExists($this->getSessionName(), $expected, 'Session');
 443   }
 444
 445   /**
 446    * Asserts whether a cookie exists on the client or not.
 447    */
 448   protected function assertCookieExists($cookie_name, $expected, $cookie_label) {
 449     $non_deleted_cookies = array_filter($this->cookies, function ($item) { return $item['value'] !== 'deleted'; });
 450     $this->assertEqual($expected, isset($non_deleted_cookies[$cookie_name]), $expected ? "$cookie_label cookie exists." : "$cookie_label cookie does not exist.");
 451   }
 452
 453   /**
 454    * Calls ::performMetaRefresh() and asserts the responses.
 455    */
 456   protected function assertBigPipeNoJsMetaRefreshRedirect() {
 457     $original_url = $this->url;
 458     $this->performMetaRefresh();
 459
 460     $this->assertEqual($original_url, $this->url, 'Redirected back to the original location.');
 461
 462     $headers = $this->drupalGetHeaders(TRUE);
 463     $this->assertEqual(2, count($headers), 'Two requests were made upon following the <meta> refresh, there are headers for two responses.');
 464
 465     // First response: redirect.
 466     $this->assertEqual('HTTP/1.1 302 Found', $headers[0][':status'], 'The first response was a 302 (redirect).');
 467     $this->assertIdentical(0, strpos($headers[0]['set-cookie'], 'big_pipe_nojs=1'), 'The first response sets the big_pipe_nojs cookie.');
 468     $this->assertEqual($original_url, $headers[0]['location'], 'The first response redirected back to the original page.');
 469     $this->assertTrue(empty(array_diff(['cookies:big_pipe_nojs', 'session.exists'], explode(' ', $headers[0]['x-drupal-cache-contexts']))), 'The first response varies by the "cookies:big_pipe_nojs" and "session.exists" cache contexts.');
 470     $this->assertFalse(isset($headers[0]['surrogate-control']), 'The first response has no "Surrogate-Control" header.');
 471
 472     // Second response: redirect followed.
 473     $this->assertEqual('HTTP/1.1 200 OK', $headers[1][':status'], 'The second response was a 200.');
 474     $this->assertTrue(empty(array_diff(['cookies:big_pipe_nojs', 'session.exists'], explode(' ', $headers[0]['x-drupal-cache-contexts']))), 'The first response varies by the "cookies:big_pipe_nojs" and "session.exists" cache contexts.');
 475     $this->assertEqual('no-store, content="BigPipe/1.0"', $headers[1]['surrogate-control'], 'The second response has a "Surrogate-Control" header.');
 476
 477     $this->assertNoRaw('<noscript><meta http-equiv="Refresh" content="0; URL=', 'Once the BigPipe no-JS cookie is set, the <meta> refresh is absent: only one redirect ever happens.');
 478   }
 479
 480 }