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

   1 <?php
   2
   3 namespace Drupal\Tests\big_pipe\Functional;
   4
   5 use Behat\Mink\Element\NodeElement;
   6 use Drupal\big_pipe\Render\Placeholder\BigPipeStrategy;
   7 use Drupal\big_pipe\Render\BigPipe;
   8 use Drupal\big_pipe_test\BigPipePlaceholderTestCases;
   9 use Drupal\Component\Serialization\Json;
  10 use Drupal\Component\Utility\Html;
  11 use Drupal\Core\Logger\RfcLogLevel;
  12 use Drupal\Core\Url;
  13 use Drupal\Tests\BrowserTestBase;
  14
  15 /**
  16  * Tests BigPipe's no-JS detection & response delivery (with and without JS).
  17  *
  18  * Covers:
  19  * - big_pipe_page_attachments()
  20  * - \Drupal\big_pipe\Controller\BigPipeController
  21  * - \Drupal\big_pipe\EventSubscriber\HtmlResponseBigPipeSubscriber
  22  * - \Drupal\big_pipe\Render\BigPipe
  23  *
  24  * @group big_pipe
  25  */
  26 class BigPipeTest extends BrowserTestBase {
  27
  28   /**
  29    * Modules to enable.
  30    *
  31    * @var array
  32    */
  33   public static $modules = ['big_pipe', 'big_pipe_test', 'dblog'];
  34
  35   /**
  36    * {@inheritdoc}
  37    */
  38   protected $dumpHeaders = TRUE;
  39
  40   /**
  41    * {@inheritdoc}
  42    */
  43   protected function setUp() {
  44     parent::setUp();
  45
  46     // Ignore the <meta> refresh that big_pipe.module sets. It causes a redirect
  47     // to a page that sets another cookie, which causes WebTestBase to lose the
  48     // session cookie. To avoid this problem, tests should first call
  49     // drupalGet() and then call checkForMetaRefresh() manually, and then reset
  50     // $this->maximumMetaRefreshCount and $this->metaRefreshCount.
  51     // @see doMetaRefresh()
  52     $this->maximumMetaRefreshCount = 0;
  53   }
  54
  55   /**
  56    * Performs a single <meta> refresh explicitly.
  57    *
  58    * This test disables the automatic <meta> refresh checking, each time it is
  59    * desired that this runs, a test case must explicitly call this.
  60    *
  61    * @see setUp()
  62    */
  63   protected function performMetaRefresh() {
  64     $this->maximumMetaRefreshCount = 1;
  65     $this->checkForMetaRefresh();
  66     $this->maximumMetaRefreshCount = 0;
  67     $this->metaRefreshCount = 0;
  68   }
  69
  70   /**
  71    * Tests BigPipe's no-JS detection.
  72    *
  73    * Covers:
  74    * - big_pipe_page_attachments()
  75    * - \Drupal\big_pipe\Controller\BigPipeController
  76    */
  77   public function testNoJsDetection() {
  78     $no_js_to_js_markup = '<script>document.cookie = "' . BigPipeStrategy::NOJS_COOKIE . '=1; path=/; expires=Thu, 01 Jan 1970 00:00:00 GMT"</script>';
  79
  80     // 1. No session (anonymous).
  81     $this->drupalGet(Url::fromRoute('<front>'));
  82     $this->assertSessionCookieExists(FALSE);
  83     $this->assertBigPipeNoJsCookieExists(FALSE);
  84     $this->assertNoRaw('<noscript><meta http-equiv="Refresh" content="0; URL=');
  85     $this->assertNoRaw($no_js_to_js_markup);
  86
  87     // 2. Session (authenticated).
  88     $this->drupalLogin($this->rootUser);
  89     $this->assertSessionCookieExists(TRUE);
  90     $this->assertBigPipeNoJsCookieExists(FALSE);
  91     $this->assertRaw('<noscript><meta http-equiv="Refresh" content="0; URL=' . base_path() . 'big_pipe/no-js?destination=' . base_path() . 'user/1" />' . "\n" . '</noscript>');
  92     $this->assertNoRaw($no_js_to_js_markup);
  93     $this->assertBigPipeNoJsMetaRefreshRedirect();
  94     $this->assertBigPipeNoJsCookieExists(TRUE);
  95     $this->assertNoRaw('<noscript><meta http-equiv="Refresh" content="0; URL=');
  96     $this->assertRaw($no_js_to_js_markup);
  97     $this->drupalLogout();
  98
  99     // Close the prior connection and remove the collected state.
 100     $this->getSession()->reset();
 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->getSession()->reset();
 116
 117     // Edge case: route with '_no_big_pipe' option.
 118     $this->drupalGet(Url::fromRoute('no_big_pipe'));
 119     $this->assertSessionCookieExists(FALSE);
 120     $this->assertBigPipeNoJsCookieExists(FALSE);
 121     $this->assertNoRaw('<noscript><meta http-equiv="Refresh" content="0; URL=');
 122     $this->assertNoRaw($no_js_to_js_markup);
 123     $this->drupalLogin($this->rootUser);
 124     $this->drupalGet(Url::fromRoute('no_big_pipe'));
 125     $this->assertSessionCookieExists(TRUE);
 126     $this->assertBigPipeNoJsCookieExists(FALSE);
 127     $this->assertNoRaw('<noscript><meta http-equiv="Refresh" content="0; URL=');
 128     $this->assertNoRaw($no_js_to_js_markup);
 129   }
 130
 131   /**
 132    * Tests BigPipe-delivered HTML responses when JavaScript is enabled.
 133    *
 134    * Covers:
 135    * - \Drupal\big_pipe\EventSubscriber\HtmlResponseBigPipeSubscriber
 136    * - \Drupal\big_pipe\Render\BigPipe
 137    * - \Drupal\big_pipe\Render\BigPipe::sendPlaceholders()
 138    *
 139    * @see \Drupal\big_pipe_test\BigPipePlaceholderTestCases
 140    */
 141   public function testBigPipe() {
 142     // Simulate production.
 143     $this->config('system.logging')->set('error_level', ERROR_REPORTING_HIDE)->save();
 144
 145     $this->drupalLogin($this->rootUser);
 146     $this->assertSessionCookieExists(TRUE);
 147     $this->assertBigPipeNoJsCookieExists(FALSE);
 148
 149     $log_count = db_query('SELECT COUNT(*) FROM {watchdog}')->fetchField();
 150
 151     // By not calling performMetaRefresh() here, we simulate JavaScript being
 152     // enabled, because as far as the BigPipe module is concerned, JavaScript is
 153     // enabled in the browser as long as the BigPipe no-JS cookie is *not* set.
 154     // @see setUp()
 155     // @see performMetaRefresh()
 156
 157     $this->drupalGet(Url::fromRoute('big_pipe_test'));
 158     $this->assertBigPipeResponseHeadersPresent();
 159     $this->assertNoCacheTag('cache_tag_set_in_lazy_builder');
 160
 161     $this->setCsrfTokenSeedInTestEnvironment();
 162     $cases = $this->getTestCases();
 163     $this->assertBigPipeNoJsPlaceholders([
 164       $cases['edge_case__invalid_html']->bigPipeNoJsPlaceholder     => $cases['edge_case__invalid_html']->embeddedHtmlResponse,
 165       $cases['html_attribute_value']->bigPipeNoJsPlaceholder        => $cases['html_attribute_value']->embeddedHtmlResponse,
 166       $cases['html_attribute_value_subset']->bigPipeNoJsPlaceholder => $cases['html_attribute_value_subset']->embeddedHtmlResponse,
 167     ]);
 168     $this->assertBigPipePlaceholders([
 169       $cases['html']->bigPipePlaceholderId                             => Json::encode($cases['html']->embeddedAjaxResponseCommands),
 170       $cases['edge_case__html_non_lazy_builder']->bigPipePlaceholderId => Json::encode($cases['edge_case__html_non_lazy_builder']->embeddedAjaxResponseCommands),
 171       $cases['exception__lazy_builder']->bigPipePlaceholderId          => NULL,
 172       $cases['exception__embedded_response']->bigPipePlaceholderId     => NULL,
 173     ], [
 174       0 => $cases['edge_case__html_non_lazy_builder']->bigPipePlaceholderId,
 175       // The 'html' case contains the 'status messages' placeholder, which is
 176       // always rendered last.
 177       1 => $cases['html']->bigPipePlaceholderId,
 178     ]);
 179
 180     $this->assertRaw('</body>', 'Closing body tag present.');
 181
 182     $this->pass('Verifying BigPipe assets are present…', 'Debug');
 183     $this->assertFalse(empty($this->getDrupalSettings()), 'drupalSettings present.');
 184     $this->assertTrue(in_array('big_pipe/big_pipe', explode(',', $this->getDrupalSettings()['ajaxPageState']['libraries'])), 'BigPipe asset library is present.');
 185
 186     // Verify that the two expected exceptions are logged as errors.
 187     $this->assertEqual($log_count + 2, db_query('SELECT COUNT(*) FROM {watchdog}')->fetchField(), 'Two new watchdog entries.');
 188     $records = db_query('SELECT * FROM {watchdog} ORDER BY wid DESC LIMIT 2')->fetchAll();
 189     $this->assertEqual(RfcLogLevel::ERROR, $records[0]->severity);
 190     $this->assertTrue(FALSE !== strpos((string) unserialize($records[0]->variables)['@message'], 'Oh noes!'));
 191     $this->assertEqual(RfcLogLevel::ERROR, $records[1]->severity);
 192     $this->assertTrue(FALSE !== strpos((string) unserialize($records[1]->variables)['@message'], 'You are not allowed to say llamas are not cool!'));
 193
 194     // Verify that 4xx responses work fine. (4xx responses are handled by
 195     // subrequests to a route pointing to a controller with the desired output.)
 196     $this->drupalGet(Url::fromUri('base:non-existing-path'));
 197
 198     // Simulate development.
 199     $this->pass('Verifying BigPipe provides useful error output when an error occurs while rendering a placeholder if verbose error logging is enabled.', 'Debug');
 200     $this->config('system.logging')->set('error_level', ERROR_REPORTING_DISPLAY_VERBOSE)->save();
 201     $this->drupalGet(Url::fromRoute('big_pipe_test'));
 202     // The 'edge_case__html_exception' case throws an exception.
 203     $this->assertRaw('The website encountered an unexpected error. Please try again later');
 204     $this->assertRaw('You are not allowed to say llamas are not cool!');
 205     $this->assertNoRaw(BigPipe::STOP_SIGNAL, 'BigPipe stop signal absent: error occurred before then.');
 206     $this->assertNoRaw('</body>', 'Closing body tag absent: error occurred before then.');
 207     // The exception is expected. Do not interpret it as a test failure.
 208     unlink(\Drupal::root() . '/' . $this->siteDirectory . '/error.log');
 209   }
 210
 211   /**
 212    * Tests BigPipe-delivered HTML responses when JavaScript is disabled.
 213    *
 214    * Covers:
 215    * - \Drupal\big_pipe\EventSubscriber\HtmlResponseBigPipeSubscriber
 216    * - \Drupal\big_pipe\Render\BigPipe
 217    * - \Drupal\big_pipe\Render\BigPipe::sendNoJsPlaceholders()
 218    *
 219    * @see \Drupal\big_pipe_test\BigPipePlaceholderTestCases
 220    */
 221   public function testBigPipeNoJs() {
 222     // Simulate production.
 223     $this->config('system.logging')->set('error_level', ERROR_REPORTING_HIDE)->save();
 224
 225     $this->drupalLogin($this->rootUser);
 226     $this->assertSessionCookieExists(TRUE);
 227     $this->assertBigPipeNoJsCookieExists(FALSE);
 228
 229     // By calling performMetaRefresh() here, we simulate JavaScript being
 230     // disabled, because as far as the BigPipe module is concerned, it is
 231     // enabled in the browser when the BigPipe no-JS cookie is set.
 232     // @see setUp()
 233     // @see performMetaRefresh()
 234     $this->performMetaRefresh();
 235     $this->assertBigPipeNoJsCookieExists(TRUE);
 236
 237     $this->drupalGet(Url::fromRoute('big_pipe_test'));
 238     $this->assertBigPipeResponseHeadersPresent();
 239     $this->assertNoCacheTag('cache_tag_set_in_lazy_builder');
 240
 241     $this->setCsrfTokenSeedInTestEnvironment();
 242     $cases = $this->getTestCases();
 243     $this->assertBigPipeNoJsPlaceholders([
 244       $cases['edge_case__invalid_html']->bigPipeNoJsPlaceholder           => $cases['edge_case__invalid_html']->embeddedHtmlResponse,
 245       $cases['html_attribute_value']->bigPipeNoJsPlaceholder              => $cases['html_attribute_value']->embeddedHtmlResponse,
 246       $cases['html_attribute_value_subset']->bigPipeNoJsPlaceholder       => $cases['html_attribute_value_subset']->embeddedHtmlResponse,
 247       $cases['html']->bigPipeNoJsPlaceholder                              => $cases['html']->embeddedHtmlResponse,
 248       $cases['edge_case__html_non_lazy_builder']->bigPipeNoJsPlaceholder  => $cases['edge_case__html_non_lazy_builder']->embeddedHtmlResponse,
 249       $cases['exception__lazy_builder']->bigPipePlaceholderId             => NULL,
 250       $cases['exception__embedded_response']->bigPipePlaceholderId        => NULL,
 251     ]);
 252
 253     $this->pass('Verifying there are no BigPipe placeholders & replacements…', 'Debug');
 254     $this->assertEqual('<none>', $this->drupalGetHeader('BigPipe-Test-Placeholders'));
 255     $this->pass('Verifying BigPipe start/stop signals are absent…', 'Debug');
 256     $this->assertNoRaw(BigPipe::START_SIGNAL, 'BigPipe start signal absent.');
 257     $this->assertNoRaw(BigPipe::STOP_SIGNAL, 'BigPipe stop signal absent.');
 258
 259     $this->pass('Verifying BigPipe assets are absent…', 'Debug');
 260     $this->assertTrue(!isset($this->getDrupalSettings()['bigPipePlaceholderIds']) && empty($this->getDrupalSettings()['ajaxPageState']), 'BigPipe drupalSettings and BigPipe asset library absent.');
 261     $this->assertRaw('</body>', 'Closing body tag present.');
 262
 263     // Verify that 4xx responses work fine. (4xx responses are handled by
 264     // subrequests to a route pointing to a controller with the desired output.)
 265     $this->drupalGet(Url::fromUri('base:non-existing-path'));
 266
 267     // Simulate development.
 268     $this->pass('Verifying BigPipe provides useful error output when an error occurs while rendering a placeholder if verbose error logging is enabled.', 'Debug');
 269     $this->config('system.logging')->set('error_level', ERROR_REPORTING_DISPLAY_VERBOSE)->save();
 270     $this->drupalGet(Url::fromRoute('big_pipe_test'));
 271     // The 'edge_case__html_exception' case throws an exception.
 272     $this->assertRaw('The website encountered an unexpected error. Please try again later');
 273     $this->assertRaw('You are not allowed to say llamas are not cool!');
 274     $this->assertNoRaw('</body>', 'Closing body tag absent: error occurred before then.');
 275     // The exception is expected. Do not interpret it as a test failure.
 276     unlink(\Drupal::root() . '/' . $this->siteDirectory . '/error.log');
 277   }
 278
 279   /**
 280    * Tests BigPipe with a multi-occurrence placeholder.
 281    */
 282   public function testBigPipeMultiOccurrencePlaceholders() {
 283     $this->drupalLogin($this->rootUser);
 284     $this->assertSessionCookieExists(TRUE);
 285     $this->assertBigPipeNoJsCookieExists(FALSE);
 286
 287     // By not calling performMetaRefresh() here, we simulate JavaScript being
 288     // enabled, because as far as the BigPipe module is concerned, JavaScript is
 289     // enabled in the browser as long as the BigPipe no-JS cookie is *not* set.
 290     // @see setUp()
 291     // @see performMetaRefresh()
 292
 293     $this->drupalGet(Url::fromRoute('big_pipe_test_multi_occurrence'));
 294     $big_pipe_placeholder_id = 'callback=Drupal%5CCore%5CRender%5CElement%5CStatusMessages%3A%3ArenderMessages&amp;args%5B0%5D&amp;token=_HAdUpwWmet0TOTe2PSiJuMntExoshbm1kh2wQzzzAA';
 295     $expected_placeholder_replacement = '<script type="application/vnd.drupal-ajax" data-big-pipe-replacement-for-placeholder-with-id="' . $big_pipe_placeholder_id . '">';
 296     $this->assertRaw('The count is 1.');
 297     $this->assertNoRaw('The count is 2.');
 298     $this->assertNoRaw('The count is 3.');
 299     $raw_content = $this->getRawContent();
 300     $this->assertTrue(substr_count($raw_content, $expected_placeholder_replacement) == 1, 'Only one placeholder replacement was found for the duplicate #lazy_builder arrays.');
 301
 302     // By calling performMetaRefresh() here, we simulate JavaScript being
 303     // disabled, because as far as the BigPipe module is concerned, it is
 304     // enabled in the browser when the BigPipe no-JS cookie is set.
 305     // @see setUp()
 306     // @see performMetaRefresh()
 307     $this->performMetaRefresh();
 308     $this->assertBigPipeNoJsCookieExists(TRUE);
 309     $this->drupalGet(Url::fromRoute('big_pipe_test_multi_occurrence'));
 310     $this->assertRaw('The count is 1.');
 311     $this->assertNoRaw('The count is 2.');
 312     $this->assertNoRaw('The count is 3.');
 313   }
 314
 315   protected function assertBigPipeResponseHeadersPresent() {
 316     $this->pass('Verifying BigPipe response headers…', 'Debug');
 317     $this->assertTrue(FALSE !== strpos($this->drupalGetHeader('Cache-Control'), 'private'), 'Cache-Control header set to "private".');
 318     $this->assertEqual('no-store, content="BigPipe/1.0"', $this->drupalGetHeader('Surrogate-Control'));
 319     $this->assertEqual('no', $this->drupalGetHeader('X-Accel-Buffering'));
 320   }
 321
 322   /**
 323    * Asserts expected BigPipe no-JS placeholders are present and replaced.
 324    *
 325    * @param array $expected_big_pipe_nojs_placeholders
 326    *   Keys: BigPipe no-JS placeholder markup. Values: expected replacement
 327    *   markup.
 328    */
 329   protected function assertBigPipeNoJsPlaceholders(array $expected_big_pipe_nojs_placeholders) {
 330     $this->pass('Verifying BigPipe no-JS placeholders & replacements…', 'Debug');
 331     $this->assertSetsEqual(array_keys($expected_big_pipe_nojs_placeholders), array_map('rawurldecode', explode(' ', $this->drupalGetHeader('BigPipe-Test-No-Js-Placeholders'))));
 332     foreach ($expected_big_pipe_nojs_placeholders as $big_pipe_nojs_placeholder => $expected_replacement) {
 333       $this->pass('Checking whether the replacement for the BigPipe no-JS placeholder "' . $big_pipe_nojs_placeholder . '" is present:');
 334       $this->assertNoRaw($big_pipe_nojs_placeholder);
 335       if ($expected_replacement !== NULL) {
 336         $this->assertRaw($expected_replacement);
 337       }
 338     }
 339   }
 340
 341   /**
 342    * Asserts expected BigPipe placeholders are present and replaced.
 343    *
 344    * @param array $expected_big_pipe_placeholders
 345    *   Keys: BigPipe placeholder IDs. Values: expected AJAX response.
 346    * @param array $expected_big_pipe_placeholder_stream_order
 347    *   Keys: BigPipe placeholder IDs. Values: expected AJAX response. Keys are
 348    *   defined in the order that they are expected to be rendered & streamed.
 349    */
 350   protected function assertBigPipePlaceholders(array $expected_big_pipe_placeholders, array $expected_big_pipe_placeholder_stream_order) {
 351     $this->pass('Verifying BigPipe placeholders & replacements…', 'Debug');
 352     $this->assertSetsEqual(array_keys($expected_big_pipe_placeholders), explode(' ', $this->drupalGetHeader('BigPipe-Test-Placeholders')));
 353     $placeholder_positions = [];
 354     $placeholder_replacement_positions = [];
 355     foreach ($expected_big_pipe_placeholders as $big_pipe_placeholder_id => $expected_ajax_response) {
 356       $this->pass('BigPipe placeholder: ' . $big_pipe_placeholder_id, 'Debug');
 357       // Verify expected placeholder.
 358       $expected_placeholder_html = '<span data-big-pipe-placeholder-id="' . $big_pipe_placeholder_id . '"></span>';
 359       $this->assertRaw($expected_placeholder_html, 'BigPipe placeholder for placeholder ID "' . $big_pipe_placeholder_id . '" found.');
 360       $pos = strpos($this->getRawContent(), $expected_placeholder_html);
 361       $placeholder_positions[$pos] = $big_pipe_placeholder_id;
 362       // Verify expected placeholder replacement.
 363       $expected_placeholder_replacement = '<script type="application/vnd.drupal-ajax" data-big-pipe-replacement-for-placeholder-with-id="' . $big_pipe_placeholder_id . '">';
 364       $result = $this->xpath('//script[@data-big-pipe-replacement-for-placeholder-with-id=:id]', [':id' => Html::decodeEntities($big_pipe_placeholder_id)]);
 365       if ($expected_ajax_response === NULL) {
 366         $this->assertEqual(0, count($result));
 367         $this->assertNoRaw($expected_placeholder_replacement);
 368         continue;
 369       }
 370       $this->assertEqual($expected_ajax_response, trim($result[0]->getText()));
 371       $this->assertRaw($expected_placeholder_replacement);
 372       $pos = strpos($this->getRawContent(), $expected_placeholder_replacement);
 373       $placeholder_replacement_positions[$pos] = $big_pipe_placeholder_id;
 374     }
 375     ksort($placeholder_positions, SORT_NUMERIC);
 376     $this->assertEqual(array_keys($expected_big_pipe_placeholders), array_values($placeholder_positions));
 377     $placeholders = array_map(function (NodeElement $element) {
 378       return $element->getAttribute('data-big-pipe-placeholder-id');
 379     }, $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->getSession()->getCookie($this->getSessionName()));
 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_test\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     $this->assertEqual($expected, !empty($this->getSession()->getCookie($cookie_name)), $expected ? "$cookie_label cookie exists." : "$cookie_label cookie does not exist.");
 450   }
 451
 452   /**
 453    * Calls ::performMetaRefresh() and asserts the responses.
 454    */
 455   protected function assertBigPipeNoJsMetaRefreshRedirect() {
 456     $original_url = $this->getSession()->getCurrentUrl();
 457
 458     // Disable automatic following of redirects by the HTTP client, so that this
 459     // test can analyze the response headers of each redirect response.
 460     $this->getSession()->getDriver()->getClient()->followRedirects(FALSE);
 461     $this->performMetaRefresh();
 462     $headers[0] = $this->getSession()->getResponseHeaders();
 463     $statuses[0] = $this->getSession()->getStatusCode();
 464     $this->performMetaRefresh();
 465     $headers[1] = $this->getSession()->getResponseHeaders();
 466     $statuses[1] = $this->getSession()->getStatusCode();
 467     $this->getSession()->getDriver()->getClient()->followRedirects(TRUE);
 468
 469     $this->assertEqual($original_url, $this->getSession()->getCurrentUrl(), 'Redirected back to the original location.');
 470
 471     // First response: redirect.
 472     $this->assertEqual(302, $statuses[0], 'The first response was a 302 (redirect).');
 473     $this->assertIdentical(0, strpos($headers[0]['Set-Cookie'][0], 'big_pipe_nojs=1'), 'The first response sets the big_pipe_nojs cookie.');
 474     $this->assertEqual($original_url, $headers[0]['Location'][0], 'The first response redirected back to the original page.');
 475     $this->assertTrue(empty(array_diff(['cookies:big_pipe_nojs', 'session.exists'], explode(' ', $headers[0]['X-Drupal-Cache-Contexts'][0]))), 'The first response varies by the "cookies:big_pipe_nojs" and "session.exists" cache contexts.');
 476     $this->assertFalse(isset($headers[0]['Surrogate-Control']), 'The first response has no "Surrogate-Control" header.');
 477
 478     // Second response: redirect followed.
 479     $this->assertEqual(200, $statuses[1], 'The second response was a 200.');
 480     $this->assertTrue(empty(array_diff(['cookies:big_pipe_nojs', 'session.exists'], explode(' ', $headers[0]['X-Drupal-Cache-Contexts'][0]))), 'The first response varies by the "cookies:big_pipe_nojs" and "session.exists" cache contexts.');
 481     $this->assertEqual('no-store, content="BigPipe/1.0"', $headers[1]['Surrogate-Control'][0], 'The second response has a "Surrogate-Control" header.');
 482
 483     $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.');
 484   }
 485
 486 }