diff --git a/core/modules/book/tests/src/FunctionalJavascript/BookJavascriptTest.php b/core/modules/book/tests/src/FunctionalJavascript/BookJavascriptTest.php
index 0b01bb6..1af143c 100644
--- a/core/modules/book/tests/src/FunctionalJavascript/BookJavascriptTest.php
+++ b/core/modules/book/tests/src/FunctionalJavascript/BookJavascriptTest.php
@@ -3,6 +3,7 @@
 namespace Drupal\Tests\book\FunctionalJavascript;
 
 use Behat\Mink\Exception\ExpectationException;
+use Drupal\Component\Render\FormattableMarkup;
 use Drupal\FunctionalJavascriptTests\JavascriptTestBase;
 use Drupal\node\Entity\Node;
 
@@ -47,8 +48,7 @@ public function testBookOrdering() {
     $this->drupalLogin($this->drupalCreateUser(['administer book outlines']));
     $this->drupalGet('admin/structure/book/' . $book->id());
 
-    $session = $this->getSession();
-    $page = $session->getPage();
+    $page = $this->getSession()->getPage();
 
     $weight_select1 = $page->findField("table[book-admin-{$page1->id()}][weight]");
     $weight_select2 = $page->findField("table[book-admin-{$page2->id()}][weight]");
@@ -58,10 +58,10 @@ public function testBookOrdering() {
     $this->assertFalse($weight_select2->isVisible());
 
     // Check that '2nd page' row is heavier than '1st page' row.
-    $this->assertTrue($weight_select2->getValue() > $weight_select1->getValue());
+    $this->assertGreaterThan($weight_select1->getValue(), $weight_select2->getValue());
 
     // Check that '1st page' precedes the '2nd page'.
-    $this->assertFirstPrecedesSecond('1st page', '2nd');
+    $this->assertOrderInPage(['1st page', '2nd page']);
 
     // Check that the 'unsaved changes' text is not present in the message area.
     $this->assertSession()->pageTextNotContains('You have unsaved changes.');
@@ -81,30 +81,30 @@ public function testBookOrdering() {
     $this->assertSession()->pageTextContains('You have unsaved changes.');
 
     // Check that '2nd page' page precedes the '1st page'.
-    $this->assertFirstPrecedesSecond('2nd page', '1st page');
+    $this->assertOrderInPage(['2nd page', '1st page']);
 
     // Toggle row weight selects as visible.
-    $page->findButton(t('Show row weights'))->click();
+    $page->findButton('Show row weights')->click();
 
     // Check that rows weight selects are visible.
     $this->assertTrue($weight_select1->isVisible());
     $this->assertTrue($weight_select2->isVisible());
 
-    // Check that '1st page' row became heavier than '1st page' row.
-    $this->assertTrue($weight_select1->getValue() > $weight_select2->getValue());
+    // Check that '1st page' row became heavier than '2nd page' row.
+    $this->assertGreaterThan($weight_select2->getValue(), $weight_select1->getValue());
 
     // Toggle row weight selects back to hidden.
-    $page->findButton(t('Hide row weights'))->click();
+    $page->findButton('Hide row weights')->click();
 
     // Check that rows weight selects are hidden again.
     $this->assertFalse($weight_select1->isVisible());
     $this->assertFalse($weight_select2->isVisible());
 
-    $this->submitForm([], t('Save book pages'));
-    $this->assertSession()->pageTextContains(t('Updated book @book.', ['@book' => $book->getTitle()]));
+    $this->submitForm([], 'Save book pages');
+    $this->assertSession()->pageTextContains(new FormattableMarkup('Updated book @book.', ['@book' => $book->getTitle()]));
 
     // Check again that '2nd page' is on top after form submit.
-    $this->assertFirstPrecedesSecond('2nd page', '1st page');
+    $this->assertOrderInPage(['2nd page', '1st page']);
 
     // Check that page reordering was done in the backend.
     $page1 = Node::load($page1->id());
@@ -113,26 +113,29 @@ public function testBookOrdering() {
   }
 
   /**
-   * Asserts that the first piece of markup precedes the second.
+   * Asserts that several pieces of markup are in a given order in the page.
    *
-   * @param string $first
-   *   The first string to be checked.
-   * @param string $second
-   *   The second string to be checked.
+   * @param string[] $items
+   *   An ordered list of strings.
    *
    * @throws \Behat\Mink\Exception\ExpectationException
-   *   When any of the strings is not found.
+   *   When any of the given string is not found.
    */
-  protected function assertFirstPrecedesSecond($first, $second) {
+  protected function assertOrderInPage(array $items) {
     $session = $this->getSession();
     $text = $session->getPage()->getHtml();
-    if (($pos1 = strpos($text, $first)) === FALSE) {
-      throw new ExpectationException("Cannot find '$first'", $session->getDriver());
-    }
-    if (($pos2 = strpos($text, $second)) === FALSE) {
-      throw new ExpectationException("Cannot find '$second'", $session->getDriver());
+    $strings = [];
+    foreach ($items as $item) {
+      if (($pos = strpos($text, $item)) === FALSE) {
+        throw new ExpectationException("Cannot find '$item' in the page", $session->getDriver());
+      }
+      $strings[$pos] = $item;
     }
-    $this->assertGreaterThan($pos1, $pos2, "'$first' precedes '$second'");
+    ksort($strings);
+    $ordered = implode(', ', array_map(function ($item) {
+      return "'$item'";
+    }, $items));
+    $this->assertSame($items, array_values($strings), "Found strings, ordered as: $ordered.");
   }
 
 }