src/Tests/BigPipeTest.php                          | 177 +++++++++++----------
 .../big_pipe_test/src/Form/BigPipeTestForm.php     |   2 +-
 .../Render/Placeholder/BigPipeStrategyTest.php     |   2 +-
 3 files changed, 91 insertions(+), 90 deletions(-)

diff --git a/src/Tests/BigPipeTest.php b/src/Tests/BigPipeTest.php
index c192b91..f44844b 100644
--- a/src/Tests/BigPipeTest.php
+++ b/src/Tests/BigPipeTest.php
@@ -122,45 +122,106 @@ class BigPipeTest extends WebTestBase {
     $this->assertSessionCookieExists(TRUE);
     $this->assertBigPipeNoJsCookieExists(FALSE);
 
-    // By not calling checkForMetaRefresh() manually here, we simulate
-    // JavaScript being enabled, because as far as the BigPipe module is
-    // concerned, JavaScript is enabled in the browser as long as the BigPipe
-    // no-JS cookie is *not* set.
+    // By not calling performMetaRefresh() here, we simulate JavaScript being
+    // enabled, because as far as the BigPipe module is concerned, JavaScript is
+    // enabled in the browser as long as the BigPipe no-JS cookie is *not* set.
     // @see setUp()
+    // @see performMetaRefresh()
 
     $this->drupalGet(Url::fromRoute('big_pipe_test'));
+    $this->assertBigPipeResponseHeadersPresent();
 
-    // Ensure we can generate CSRF tokens for the current user's session.
-    $session_data = $this->container->get('session_handler.write_safe')->read($this->cookies[$this->getSessionName()]['value']);
-    $csrf_token_seed = unserialize(explode('_sf2_meta|', $session_data)[1])['s'];
-    $this->container->get('session_manager.metadata_bag')->setCsrfTokenSeed($csrf_token_seed);
-
-    $this->pass('Verifying BigPipe response headers…', 'Debug');
-    $this->assertTrue(FALSE !== strpos($this->drupalGetHeader('Cache-Control'), 'private'), 'Cache-Control header set to "private".');
-    $this->assertEqual('no-store, content="BigPipe/1.0"', $this->drupalGetHeader('Surrogate-Control'));
-    $this->assertEqual('no', $this->drupalGetHeader('X-Accel-Buffering'));
-
-    $cases = \Drupal\big_pipe\Tests\BigPipePlaceholderTestCases::cases($this->container, $this->rootUser);
-
-    // Keys: BigPipe no-JS placeholder markup. Values: expected replacement markup.
-    $expected_big_pipe_nojs_placeholders = [
+    $cases = $this->getTestCases();
+    $this->assertBigPipeNoJsPlaceholders([
       $cases['edge_case__invalid_html']->bigPipeNoJsPlaceholder     => $cases['edge_case__invalid_html']->embeddedHtmlResponse,
       $cases['html_attribute_value']->bigPipeNoJsPlaceholder        => $cases['html_attribute_value']->embeddedHtmlResponse,
       $cases['html_attribute_value_subset']->bigPipeNoJsPlaceholder => $cases['html_attribute_value_subset']->embeddedHtmlResponse,
-    ];
-    // Keys: BigPipe placeholder IDs. Values: expected AJAX response.
-    $expected_big_pipe_placeholders = [
+    ]);
+    $this->assertBigPipePlaceholders([
       $cases['html']->bigPipePlaceholderId                             => Json::encode($cases['html']->embeddedAjaxResponseCommands),
       $cases['edge_case__html_non_lazy_builder']->bigPipePlaceholderId => Json::encode($cases['edge_case__html_non_lazy_builder']->embeddedAjaxResponseCommands),
-    ];
+    ]);
+
+    $this->pass('Verifying BigPipe assets are present…', 'Debug');
+    $this->assertFalse(empty($this->getDrupalSettings()), 'drupalSettings present.');
+    $this->assertTrue(in_array('big_pipe/big_pipe', explode(',', $this->getDrupalSettings()['ajaxPageState']['libraries'])), 'BigPipe asset library is present.');
+  }
+
+  /**
+   * Tests BigPipe-delivered HTML responses when JavaScript is disabled.
+   *
+   * Covers:
+   * - \Drupal\big_pipe\EventSubscriber\HtmlResponseBigPipeSubscriber
+   * - \Drupal\big_pipe\Render\BigPipe
+   * - \Drupal\big_pipe\Render\BigPipe::sendNoJsPlaceholders()
+   *
+   * @see \Drupal\big_pipe\Tests\BigPipePlaceholderTestCases
+   */
+  public function testBigPipeNoJs() {
+    $this->drupalLogin($this->rootUser);
+    $this->assertSessionCookieExists(TRUE);
+    $this->assertBigPipeNoJsCookieExists(FALSE);
 
+    // By calling performMetaRefresh() here, we simulate JavaScript being
+    // disabled, because as far as the BigPipe module is concerned, it is
+    // enabled in the browser when the BigPipe no-JS cookie is set.
+    // @see setUp()
+    // @see performMetaRefresh()
+    $this->performMetaRefresh();
+    $this->assertBigPipeNoJsCookieExists(TRUE);
+
+    $this->drupalGet(Url::fromRoute('big_pipe_test'));
+    $this->assertBigPipeResponseHeadersPresent();
+
+    $cases = $this->getTestCases();
+    $this->assertBigPipeNoJsPlaceholders([
+      $cases['edge_case__invalid_html']->bigPipeNoJsPlaceholder           => $cases['edge_case__invalid_html']->embeddedHtmlResponse,
+      $cases['html_attribute_value']->bigPipeNoJsPlaceholder              => $cases['html_attribute_value']->embeddedHtmlResponse,
+      $cases['html_attribute_value_subset']->bigPipeNoJsPlaceholder       => $cases['html_attribute_value_subset']->embeddedHtmlResponse,
+      $cases['html']->bigPipeNoJsPlaceholder                              => $cases['html']->embeddedHtmlResponse,
+      $cases['edge_case__html_non_lazy_builder']->bigPipeNoJsPlaceholder  => $cases['edge_case__html_non_lazy_builder']->embeddedHtmlResponse,
+    ]);
+
+    $this->pass('Verifying there are no BigPipe placeholders & replacements…', 'Debug');
+    $this->assertEqual('<none>', $this->drupalGetHeader('BigPipe-Test-Placeholders'));
+    $this->pass('Verifying BigPipe start/stop signals are absent…', 'Debug');
+    $this->assertNoRaw(static::START_SIGNAL, 'BigPipe start signal absent.');
+    $this->assertNoRaw(static::STOP_SIGNAL, 'BigPipe stop signal absent.');
+
+    $this->pass('Verifying BigPipe assets are absent…', 'Debug');
+    $this->assertFalse(empty($this->getDrupalSettings()), 'drupalSettings and BigPipe asset library absent.');
+  }
+
+  protected function assertBigPipeResponseHeadersPresent() {
+    $this->pass('Verifying BigPipe response headers…', 'Debug');
+    $this->assertTrue(FALSE !== strpos($this->drupalGetHeader('Cache-Control'), 'private'), 'Cache-Control header set to "private".');
+    $this->assertEqual('no-store, content="BigPipe/1.0"', $this->drupalGetHeader('Surrogate-Control'));
+    $this->assertEqual('no', $this->drupalGetHeader('X-Accel-Buffering'));
+  }
+
+  /**
+   * Asserts expected BigPipe no-JS placeholders are present and replaced.
+   *
+   * @param array $expected_big_pipe_nojs_placeholders
+   *   Keys: BigPipe no-JS placeholder markup. Values: expected replacement
+   *   markup.
+   */
+  protected function assertBigPipeNoJsPlaceholders(array $expected_big_pipe_nojs_placeholders) {
     $this->pass('Verifying BigPipe no-JS placeholders & replacements…', 'Debug');
     $this->assertSetsEqual(array_keys($expected_big_pipe_nojs_placeholders), array_map('rawurldecode', explode(' ', $this->drupalGetHeader('BigPipe-Test-No-Js-Placeholders'))));
     foreach ($expected_big_pipe_nojs_placeholders as $big_pipe_nojs_placeholder => $expected_replacement) {
       $this->pass('Checking whether the replacement for the BigPipe no-JS placeholder "' . $big_pipe_nojs_placeholder . '" is present:');
       $this->assertRaw($expected_replacement);
     }
+  }
 
+  /**
+   * Asserts expected BigPipe placeholders are present and replaced.
+   *
+   * @param array $expected_big_pipe_placeholders
+   *   Keys: BigPipe placeholder IDs. Values: expected AJAX response.
+   */
+  protected function assertBigPipePlaceholders(array $expected_big_pipe_placeholders) {
     $this->pass('Verifying BigPipe placeholders & replacements…', 'Debug');
     $this->assertSetsEqual(array_keys($expected_big_pipe_placeholders), explode(' ', $this->drupalGetHeader('BigPipe-Test-Placeholders')));
     $placeholder_positions = [];
@@ -186,10 +247,6 @@ class BigPipeTest extends WebTestBase {
     $this->assertEqual(array_keys($expected_big_pipe_placeholders), array_values($placeholder_replacement_positions));
     $this->assertEqual(count($expected_big_pipe_placeholders), preg_match_all('/' . preg_quote('<script type="application/json" data-big-pipe-replacement-for-placeholder-with-id="', '/') . '/', $this->getRawContent()));
 
-    $this->pass('Verifying BigPipe assets are present…', 'Debug');
-    $this->assertFalse(empty($this->getDrupalSettings()), 'drupalSettings present.');
-    $this->assertTrue(in_array('big_pipe/big_pipe', explode(',', $this->getDrupalSettings()['ajaxPageState']['libraries'])), 'BigPipe asset library is present.');
-
     $this->pass('Verifying BigPipe start/stop signals…', 'Debug');
     $this->assertRaw(static::START_SIGNAL, 'BigPipe start signal present.');
     $this->assertRaw(static::STOP_SIGNAL, 'BigPipe stop signal present.');
@@ -202,75 +259,20 @@ class BigPipeTest extends WebTestBase {
     array_unshift($expected_stream_order, static::START_SIGNAL);
     array_push($expected_stream_order, static::STOP_SIGNAL);
     $actual_stream_order = $placeholder_replacement_positions + [
-      $start_signal_position => static::START_SIGNAL,
-      $stop_signal_position => static::STOP_SIGNAL,
-    ];
+        $start_signal_position => static::START_SIGNAL,
+        $stop_signal_position => static::STOP_SIGNAL,
+      ];
     ksort($actual_stream_order, SORT_NUMERIC);
     $this->assertEqual($expected_stream_order, array_values($actual_stream_order));
   }
 
-  /**
-   * Tests BigPipe-delivered HTML responses when JavaScript is disabled.
-   *
-   * Covers:
-   * - \Drupal\big_pipe\EventSubscriber\HtmlResponseBigPipeSubscriber
-   * - \Drupal\big_pipe\Render\BigPipe
-   * - \Drupal\big_pipe\Render\BigPipe::sendNoJsPlaceholders()
-   *
-   * @see \Drupal\big_pipe\Tests\BigPipePlaceholderTestCases
-   */
-  public function testBigPipeNoJs() {
-    $this->drupalLogin($this->rootUser);
-    $this->assertSessionCookieExists(TRUE);
-    $this->assertBigPipeNoJsCookieExists(FALSE);
-
-    // By calling checkForMetaRefresh() manually here, we simulate JavaScript
-    // being disabled, because as far as the BigPipe module is concerned, it is
-    // enabled in the browser when the BigPipe no-JS cookie is set.
-    // @see setUp()
-    $this->performMetaRefresh();
-    $this->assertBigPipeNoJsCookieExists(TRUE);
-
-    $this->drupalGet(Url::fromRoute('big_pipe_test'));
-
+  protected function getTestCases() {
     // Ensure we can generate CSRF tokens for the current user's session.
     $session_data = $this->container->get('session_handler.write_safe')->read($this->cookies[$this->getSessionName()]['value']);
     $csrf_token_seed = unserialize(explode('_sf2_meta|', $session_data)[1])['s'];
     $this->container->get('session_manager.metadata_bag')->setCsrfTokenSeed($csrf_token_seed);
 
-    $this->pass('Verifying BigPipe response headers…', 'Debug');
-    $this->assertTrue(FALSE !== strpos($this->drupalGetHeader('Cache-Control'), 'private'), 'Cache-Control header set to "private".');
-    $this->assertEqual('no-store, content="BigPipe/1.0"', $this->drupalGetHeader('Surrogate-Control'));
-    $this->assertEqual('no', $this->drupalGetHeader('X-Accel-Buffering'));
-
-
-    $cases = \Drupal\big_pipe\Tests\BigPipePlaceholderTestCases::cases($this->container, $this->rootUser);
-
-    // Keys: BigPipe no-JS placeholder markup. Values: expected replacement markup.
-    $expected_big_pipe_nojs_placeholders = [
-      $cases['edge_case__invalid_html']->bigPipeNoJsPlaceholder           => $cases['edge_case__invalid_html']->embeddedHtmlResponse,
-      $cases['html_attribute_value']->bigPipeNoJsPlaceholder              => $cases['html_attribute_value']->embeddedHtmlResponse,
-      $cases['html_attribute_value_subset']->bigPipeNoJsPlaceholder       => $cases['html_attribute_value_subset']->embeddedHtmlResponse,
-      $cases['html']->bigPipeNoJsPlaceholder                              => $cases['html']->embeddedHtmlResponse,
-      $cases['edge_case__html_non_lazy_builder']->bigPipeNoJsPlaceholder  => $cases['edge_case__html_non_lazy_builder']->embeddedHtmlResponse,
-    ];
-
-    $this->pass('Verifying BigPipe no-JS placeholders & replacements…', 'Debug');
-    $this->assertSetsEqual(array_keys($expected_big_pipe_nojs_placeholders), array_map('rawurldecode', explode(' ', $this->drupalGetHeader('BigPipe-Test-No-Js-Placeholders'))));
-    foreach ($expected_big_pipe_nojs_placeholders as $big_pipe_nojs_placeholder => $expected_replacement) {
-      $this->pass('Checking whether the replacement for the BigPipe no-JS placeholder "' . $big_pipe_nojs_placeholder . '" is present:');
-      $this->assertRaw($expected_replacement);
-    }
-
-    $this->pass('Verifying BigPipe placeholders & replacements…', 'Debug');
-    $this->assertEqual('<none>', $this->drupalGetHeader('BigPipe-Test-Placeholders'));
-
-    $this->pass('Verifying BigPipe assets are absent…', 'Debug');
-    $this->assertFalse(empty($this->getDrupalSettings()), 'drupalSettings and BigPipe asset library absent.');
-
-    $this->pass('Verifying BigPipe start/stop signals are absent…', 'Debug');
-    $this->assertNoRaw(static::START_SIGNAL, 'BigPipe start signal absent.');
-    $this->assertNoRaw(static::STOP_SIGNAL, 'BigPipe stop signal absent.');
+    return \Drupal\big_pipe\Tests\BigPipePlaceholderTestCases::cases($this->container, $this->rootUser);
   }
 
   /**
@@ -307,10 +309,9 @@ class BigPipeTest extends WebTestBase {
   }
 
   /**
-   * Checks the no-JS <meta> refresh, follows the redirect.
+   * Calls ::performMetaRefresh() and asserts the responses.
    */
   protected function assertBigPipeNoJsMetaRefreshRedirect() {
-    // Let the browser check for a meta refresh.
     $original_url = $this->url;
     $this->performMetaRefresh();
 
diff --git a/tests/modules/big_pipe_test/src/Form/BigPipeTestForm.php b/tests/modules/big_pipe_test/src/Form/BigPipeTestForm.php
index 14a040e..21b6462 100644
--- a/tests/modules/big_pipe_test/src/Form/BigPipeTestForm.php
+++ b/tests/modules/big_pipe_test/src/Form/BigPipeTestForm.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Contains \Drupal\search\Form\SearchBlockForm.
+ * Contains \Drupal\big_pipe_test\Form\BigPipeTestForm.
  */
 
 namespace Drupal\big_pipe_test\Form;
diff --git a/tests/src/Unit/Render/Placeholder/BigPipeStrategyTest.php b/tests/src/Unit/Render/Placeholder/BigPipeStrategyTest.php
index b6bd31b..63c4fed 100644
--- a/tests/src/Unit/Render/Placeholder/BigPipeStrategyTest.php
+++ b/tests/src/Unit/Render/Placeholder/BigPipeStrategyTest.php
@@ -44,7 +44,7 @@ class BigPipeStrategyTest extends UnitTestCase {
     $processed_placeholders = $big_pipe_strategy->processPlaceholders($placeholders);
 
     if ($request_has_session) {
-      $this->assertSameSize($placeholders, $processed_placeholders, 'BigPipe is able to deliver all placeholders.');
+      $this->assertSameSize($expected_big_pipe_placeholders, $processed_placeholders, 'BigPipe is able to deliver all placeholders.');
       foreach (array_keys($placeholders) as $placeholder) {
         $this->assertSame($expected_big_pipe_placeholders[$placeholder], $processed_placeholders[$placeholder], "Verifying how BigPipeStrategy handles the placeholder '$placeholder'");
       }