diff --git a/core/modules/book/src/Tests/BookBreadcrumbTest.php b/core/modules/book/tests/src/Functional/BookBreadcrumbTest.php
similarity index 95%
rename from core/modules/book/src/Tests/BookBreadcrumbTest.php
rename to core/modules/book/tests/src/Functional/BookBreadcrumbTest.php
index 57e1b3d..69c0d62 100644
--- a/core/modules/book/src/Tests/BookBreadcrumbTest.php
+++ b/core/modules/book/tests/src/Functional/BookBreadcrumbTest.php
@@ -1,15 +1,15 @@
 <?php
 
-namespace Drupal\book\Tests;
+namespace Drupal\Tests\book\Functional;
 
-use Drupal\simpletest\WebTestBase;
+use Drupal\Tests\BrowserTestBase;
 
 /**
  * Create a book, add pages, and test book interface.
  *
  * @group book
  */
-class BookBreadcrumbTest extends WebTestBase {
+class BookBreadcrumbTest extends BrowserTestBase {
 
   /**
    * Modules to install.
@@ -148,7 +148,7 @@ public function testBreadcrumbTitleUpdates() {
     $links = $this->xpath('//nav[@class="breadcrumb"]/ol/li/a');
     $got_breadcrumb = [];
     foreach ($links as $link) {
-      $got_breadcrumb[] = (string) $link;
+      $got_breadcrumb[] = $link->getText();
     }
     // Home link and four parent book nodes should be in the breadcrumb.
     $this->assertEqual(5, count($got_breadcrumb));
@@ -162,7 +162,7 @@ public function testBreadcrumbTitleUpdates() {
     $links = $this->xpath('//nav[@class="breadcrumb"]/ol/li/a');
     $got_breadcrumb = [];
     foreach ($links as $link) {
-      $got_breadcrumb[] = (string) $link;
+      $got_breadcrumb[] = $link->getText();
     }
     $this->assertEqual(5, count($got_breadcrumb));
     $this->assertEqual($edit['title[0][value]'], end($got_breadcrumb));
@@ -183,7 +183,7 @@ public function testBreadcrumbAccessUpdates() {
     $links = $this->xpath('//nav[@class="breadcrumb"]/ol/li/a');
     $got_breadcrumb = [];
     foreach ($links as $link) {
-      $got_breadcrumb[] = (string) $link;
+      $got_breadcrumb[] = $link->getText();
     }
     $this->assertEqual(5, count($got_breadcrumb));
     $this->assertEqual($edit['title[0][value]'], end($got_breadcrumb));
@@ -193,7 +193,7 @@ public function testBreadcrumbAccessUpdates() {
     $links = $this->xpath('//nav[@class="breadcrumb"]/ol/li/a');
     $got_breadcrumb = [];
     foreach ($links as $link) {
-      $got_breadcrumb[] = (string) $link;
+      $got_breadcrumb[] = $link->getText();
     }
     $this->assertEqual(4, count($got_breadcrumb));
     $this->assertEqual($nodes[2]->getTitle(), end($got_breadcrumb));
diff --git a/core/modules/book/src/Tests/BookInstallTest.php b/core/modules/book/tests/src/Functional/BookInstallTest.php
similarity index 88%
rename from core/modules/book/src/Tests/BookInstallTest.php
rename to core/modules/book/tests/src/Functional/BookInstallTest.php
index ba70a9b..9dde5e8 100644
--- a/core/modules/book/src/Tests/BookInstallTest.php
+++ b/core/modules/book/tests/src/Functional/BookInstallTest.php
@@ -1,8 +1,8 @@
 <?php
 
-namespace Drupal\book\Tests;
+namespace Drupal\Tests\book\Functional;
 
-use Drupal\simpletest\WebTestBase;
+use Drupal\Tests\BrowserTestBase;
 use Drupal\Core\Config\PreExistingConfigException;
 
 /**
@@ -10,7 +10,7 @@
  *
  * @group book
  */
-class BookInstallTest extends WebTestBase {
+class BookInstallTest extends BrowserTestBase {
 
   /**
    * Modules to install.
diff --git a/core/modules/book/src/Tests/BookTest.php b/core/modules/book/tests/src/Functional/BookTest.php
similarity index 99%
rename from core/modules/book/src/Tests/BookTest.php
rename to core/modules/book/tests/src/Functional/BookTest.php
index cdd61c6..e56fc31 100644
--- a/core/modules/book/src/Tests/BookTest.php
+++ b/core/modules/book/tests/src/Functional/BookTest.php
@@ -1,11 +1,11 @@
 <?php
 
-namespace Drupal\book\Tests;
+namespace Drupal\Tests\book\Functional;
 
 use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Entity\EntityInterface;
-use Drupal\simpletest\WebTestBase;
+use Drupal\Tests\BrowserTestBase;
 use Drupal\user\RoleInterface;
 
 /**
@@ -13,7 +13,7 @@
  *
  * @group book
  */
-class BookTest extends WebTestBase {
+class BookTest extends BrowserTestBase {
 
   /**
    * Modules to install.
@@ -296,7 +296,7 @@ function checkBookNode(EntityInterface $node, $nodes, $previous = FALSE, $up = F
     $links = $this->xpath('//nav[@class="breadcrumb"]/ol/li/a');
     $got_breadcrumb = [];
     foreach ($links as $link) {
-      $got_breadcrumb[] = (string) $link['href'];
+      $got_breadcrumb[] = $link->getAttribute('href');
     }
 
     // Compare expected and got breadcrumbs.
@@ -690,7 +690,7 @@ public function testAdminBookNodeListing() {
     $this->assertText($this->book->label(), 'The book title is displayed on the administrative book listing page.');
 
     $elements = $this->xpath('//table//ul[@class="dropbutton"]/li/a');
-    $this->assertEqual((string) $elements[0], 'View', 'View link is found from the list.');
+    $this->assertEqual($elements[0]->getText(), 'View', 'View link is found from the list.');
   }
 
   /**