diff --git a/core/modules/taxonomy/tests/src/Functional/RssTest.php b/core/modules/taxonomy/src/Tests/RssTest.php
similarity index 92%
rename from core/modules/taxonomy/tests/src/Functional/RssTest.php
rename to core/modules/taxonomy/src/Tests/RssTest.php
index 2f22196469154f9dc3ff69bbaf7be7507ac909de..c4f48846b436e6f2911f25f988cef7fa67143d7d 100644
--- a/core/modules/taxonomy/tests/src/Functional/RssTest.php
+++ b/core/modules/taxonomy/src/Tests/RssTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Drupal\Tests\taxonomy\Functional;
+namespace Drupal\taxonomy\Tests;
 
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
 use Drupal\views\Views;
@@ -106,11 +106,7 @@ public function testTaxonomyRss() {
 
     // Test that the feed page exists for the term.
     $this->drupalGet("taxonomy/term/{$term1->id()}/feed");
-    $assert = $this->assertSession();
-    $assert->responseHeaderContains('Content-Type', 'application/rss+xml');
-    // Ensure the RSS version is 2.0.
-    $rss_array = $this->getSession()->getDriver()->find('rss');
-    $this->assertEquals('2.0', reset($rss_array)->getAttribute('version'));
+    $this->assertTrue(!empty($this->cssSelect('rss[version="2.0"]')), "Feed page is RSS.");
 
     // Check that the "Exception value" is disabled by default.
     $this->drupalGet('taxonomy/term/all/feed');
diff --git a/core/modules/taxonomy/tests/src/Functional/TaxonomyTermIndentationTest.php b/core/modules/taxonomy/src/Tests/TaxonomyTermIndentationTest.php
similarity index 71%
rename from core/modules/taxonomy/tests/src/Functional/TaxonomyTermIndentationTest.php
rename to core/modules/taxonomy/src/Tests/TaxonomyTermIndentationTest.php
index 13dcb7e1cba2a666a02cceda57d13e56c8ee7548..599b6fb2c7a790244aa18e90ba71017c0a23337e 100644
--- a/core/modules/taxonomy/tests/src/Functional/TaxonomyTermIndentationTest.php
+++ b/core/modules/taxonomy/src/Tests/TaxonomyTermIndentationTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Drupal\Tests\taxonomy\Functional;
+namespace Drupal\taxonomy\Tests;
 
 /**
  * Ensure that the term indentation works properly.
@@ -33,7 +33,6 @@ protected function setUp() {
    * Tests term indentation.
    */
   public function testTermIndentation() {
-    $assert = $this->assertSession();
     // Create three taxonomy terms.
     $term1 = $this->createTerm($this->vocabulary);
     $term2 = $this->createTerm($this->vocabulary);
@@ -43,23 +42,15 @@ public function testTermIndentation() {
     $taxonomy_storage = $this->container->get('entity.manager')->getStorage('taxonomy_term');
 
     // Indent the second term under the first one.
-    $this->drupalGet('admin/structure/taxonomy/manage/' . $this->vocabulary->get('vid') . '/overview');
-    $hidden_edit = [
+    $edit = [
       'terms[tid:' . $term2->id() . ':0][term][tid]' => 2,
       'terms[tid:' . $term2->id() . ':0][term][parent]' => 1,
       'terms[tid:' . $term2->id() . ':0][term][depth]' => 1,
-    ];
-    // Because we can't post hidden form elements, we have to change them in
-    // code here, and then submit.
-    foreach ($hidden_edit as $field => $value) {
-      $node = $assert->hiddenFieldExists($field);
-      $node->setValue($value);
-    }
-    $edit = [
       'terms[tid:' . $term2->id() . ':0][weight]' => 1,
     ];
+
     // Submit the edited form and check for HTML indentation element presence.
-    $this->drupalPostForm(NULL, $edit, t('Save'));
+    $this->drupalPostForm('admin/structure/taxonomy/manage/' . $this->vocabulary->get('vid') . '/overview', $edit, t('Save'));
     $this->assertPattern('|<div class="js-indentation indentation">&nbsp;</div>|');
 
     // Check explicitly that term 2's parent is term 1.
@@ -67,22 +58,14 @@ public function testTermIndentation() {
     $this->assertEqual(key($parents), 1, 'Term 1 is the term 2\'s parent');
 
     // Move the second term back out to the root level.
-    $this->drupalGet('admin/structure/taxonomy/manage/' . $this->vocabulary->get('vid') . '/overview');
-    $hidden_edit = [
+    $edit = [
       'terms[tid:' . $term2->id() . ':0][term][tid]' => 2,
       'terms[tid:' . $term2->id() . ':0][term][parent]' => 0,
       'terms[tid:' . $term2->id() . ':0][term][depth]' => 0,
-    ];
-    // Because we can't post hidden form elements, we have to change them in
-    // code here, and then submit.
-    foreach ($hidden_edit as $field => $value) {
-      $node = $assert->hiddenFieldExists($field);
-      $node->setValue($value);
-    }
-    $edit = [
       'terms[tid:' . $term2->id() . ':0][weight]' => 1,
     ];
-    $this->drupalPostForm(NULL, $edit, t('Save'));
+
+    $this->drupalPostForm('admin/structure/taxonomy/manage/' . $this->vocabulary->get('vid') . '/overview', $edit, t('Save'));
     // All terms back at the root level, no indentation should be present.
     $this->assertNoPattern('|<div class="js-indentation indentation">&nbsp;</div>|');
 
diff --git a/core/modules/taxonomy/tests/src/Functional/TermAutocompleteTest.php b/core/modules/taxonomy/src/Tests/TermAutocompleteTest.php
similarity index 82%
rename from core/modules/taxonomy/tests/src/Functional/TermAutocompleteTest.php
rename to core/modules/taxonomy/src/Tests/TermAutocompleteTest.php
index 6304976176a7cf935a6d8395115c753104688523..ce28b1285d76055eabb959f07ae8596ef3d899cb 100644
--- a/core/modules/taxonomy/tests/src/Functional/TermAutocompleteTest.php
+++ b/core/modules/taxonomy/src/Tests/TermAutocompleteTest.php
@@ -1,8 +1,7 @@
 <?php
 
-namespace Drupal\Tests\taxonomy\Functional;
+namespace Drupal\taxonomy\Tests;
 
-use Drupal\Component\Serialization\Json;
 use Drupal\Core\Entity\Entity\EntityFormDisplay;
 use Drupal\Core\Entity\Entity\EntityViewDisplay;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
@@ -16,13 +15,6 @@
  */
 class TermAutocompleteTest extends TaxonomyTestBase {
 
-  /**
-   * Modules to enable.
-   *
-   * @var array
-   */
-  public static $modules = ['node'];
-
   /**
    * The vocabulary.
    *
@@ -135,25 +127,7 @@ protected function setUp() {
     // Retrieve the autocomplete url.
     $this->drupalGet('node/add/article');
     $result = $this->xpath('//input[@name="' . $this->fieldName . '[0][target_id]"]');
-    $this->autocompleteUrl = $this->getAbsoluteUrl($result[0]->getAttribute('data-autocomplete-path'));
-  }
-
-  /**
-   * Helper function for JSON formatted requests.
-   *
-   * @param string|\Drupal\Core\Url $path
-   *   Drupal path or URL to load into Mink controlled browser.
-   * @param array $options
-   *   (optional) Options to be forwarded to the url generator.
-   * @param string[] $headers
-   *   (optional) An array containing additional HTTP request headers.
-   *
-   * @return string[]
-   *   Array representing decoded JSON response.
-   */
-  protected function drupalGetJson($path, array $options = [], array $headers = []) {
-    $options = array_merge_recursive(['query' => ['_format' => 'json']], $options);
-    return Json::decode($this->drupalGet($path, $options, $headers));
+    $this->autocompleteUrl = $this->getAbsoluteUrl($result[0]['data-autocomplete-path']);
   }
 
   /**
@@ -163,21 +137,21 @@ protected function drupalGetJson($path, array $options = [], array $headers = []
    */
   public function testAutocompleteCountResults() {
     // Test that no matching term found.
-    $data = $this->drupalGetJson(
+    $data = $this->drupalGetJSON(
       $this->autocompleteUrl,
       ['query' => ['q' => 'zzz']]
     );
     $this->assertTrue(empty($data), 'Autocomplete returned no results');
 
     // Test that only one matching term found, when only one matches.
-    $data = $this->drupalGetJson(
+    $data = $this->drupalGetJSON(
       $this->autocompleteUrl,
       ['query' => ['q' => 'aaa 10']]
     );
     $this->assertEqual(1, count($data), 'Autocomplete returned 1 result');
 
     // Test the correct number of matches when multiple are partial matches.
-    $data = $this->drupalGetJson(
+    $data = $this->drupalGetJSON(
       $this->autocompleteUrl,
       ['query' => ['q' => 'aaa 1']]
     );
@@ -185,7 +159,7 @@ public function testAutocompleteCountResults() {
 
     // Tests that only 10 results are returned, even if there are more than 10
     // matches.
-    $data = $this->drupalGetJson(
+    $data = $this->drupalGetJSON(
       $this->autocompleteUrl,
       ['query' => ['q' => 'aaa']]
     );
@@ -218,7 +192,7 @@ public function testAutocompleteOrderedResults() {
       ];
     }
 
-    $data = $this->drupalGetJson(
+    $data = $this->drupalGetJSON(
       $this->autocompleteUrl,
       ['query' => ['q' => 'bbb']]
     );
diff --git a/core/modules/taxonomy/tests/src/Functional/TermTest.php b/core/modules/taxonomy/src/Tests/TermTest.php
similarity index 95%
rename from core/modules/taxonomy/tests/src/Functional/TermTest.php
rename to core/modules/taxonomy/src/Tests/TermTest.php
index cce58da942ba60ea483ace7408bcb89caaa4f209..54309c4237e2a8f5089c93fc2c1aea53880a7eaf 100644
--- a/core/modules/taxonomy/tests/src/Functional/TermTest.php
+++ b/core/modules/taxonomy/src/Tests/TermTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Drupal\Tests\taxonomy\Functional;
+namespace Drupal\taxonomy\Tests;
 
 use Drupal\Component\Utility\Tags;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
@@ -389,7 +389,6 @@ public function testTermInterface() {
    * Save, edit and delete a term using the user interface.
    */
   public function testTermReorder() {
-    $assert = $this->assertSession();
     $this->createTerm($this->vocabulary);
     $this->createTerm($this->vocabulary);
     $this->createTerm($this->vocabulary);
@@ -407,30 +406,21 @@ public function testTermReorder() {
     // "tid:1:0[depth]", and "tid:1:0[weight]". Change the order to term2,
     // term3, term1 by setting weight property, make term3 a child of term2 by
     // setting the parent and depth properties, and update all hidden fields.
-    $hidden_edit = [
+    $edit = [
       'terms[tid:' . $term2->id() . ':0][term][tid]' => $term2->id(),
       'terms[tid:' . $term2->id() . ':0][term][parent]' => 0,
       'terms[tid:' . $term2->id() . ':0][term][depth]' => 0,
+      'terms[tid:' . $term2->id() . ':0][weight]' => 0,
       'terms[tid:' . $term3->id() . ':0][term][tid]' => $term3->id(),
       'terms[tid:' . $term3->id() . ':0][term][parent]' => $term2->id(),
       'terms[tid:' . $term3->id() . ':0][term][depth]' => 1,
+      'terms[tid:' . $term3->id() . ':0][weight]' => 1,
       'terms[tid:' . $term1->id() . ':0][term][tid]' => $term1->id(),
       'terms[tid:' . $term1->id() . ':0][term][parent]' => 0,
       'terms[tid:' . $term1->id() . ':0][term][depth]' => 0,
-    ];
-    // Because we can't post hidden form elements, we have to change them in
-    // code here, and then submit.
-    foreach ($hidden_edit as $field => $value) {
-      $node = $assert->hiddenFieldExists($field);
-      $node->setValue($value);
-    }
-    // Edit non-hidden elements within drupalPostForm().
-    $edit = [
-      'terms[tid:' . $term2->id() . ':0][weight]' => 0,
-      'terms[tid:' . $term3->id() . ':0][weight]' => 1,
       'terms[tid:' . $term1->id() . ':0][weight]' => 2,
     ];
-    $this->drupalPostForm(NULL, $edit, 'Save');
+    $this->drupalPostForm(NULL, $edit, t('Save'));
 
     $taxonomy_storage->resetCache();
     $terms = $taxonomy_storage->loadTree($this->vocabulary->id());
@@ -580,7 +570,7 @@ public function testTermBreadcrumbs() {
     ];
 
     // Create the term.
-    $this->drupalPostForm('admin/structure/taxonomy/manage/' . $this->vocabulary->id() . '/add', $edit, 'Save');
+    $this->drupalPostForm('admin/structure/taxonomy/manage/' . $this->vocabulary->id() . '/add', $edit, t('Save'));
 
     $terms = taxonomy_term_load_multiple_by_name($edit['name[0][value]']);
     $term = reset($terms);
@@ -588,19 +578,19 @@ public function testTermBreadcrumbs() {
 
     // Check the breadcrumb on the term edit page.
     $this->drupalGet('taxonomy/term/' . $term->id() . '/edit');
-    $breadcrumbs = $this->getSession()->getPage()->findAll('css', 'nav.breadcrumb ol li a');
+    $breadcrumbs = $this->cssSelect('nav.breadcrumb ol li a');
     $this->assertIdentical(count($breadcrumbs), 2, 'The breadcrumbs are present on the page.');
-    $this->assertIdentical($breadcrumbs[0]->getText(), 'Home', 'First breadcrumb text is Home');
-    $this->assertIdentical($breadcrumbs[1]->getText(), $term->label(), 'Second breadcrumb text is term name on term edit page.');
-    $this->assertEscaped($breadcrumbs[1]->getText(), 'breadcrumbs displayed and escaped.');
+    $this->assertIdentical((string) $breadcrumbs[0], 'Home', 'First breadcrumb text is Home');
+    $this->assertIdentical((string) $breadcrumbs[1], $term->label(), 'Second breadcrumb text is term name on term edit page.');
+    $this->assertEscaped((string) $breadcrumbs[1], 'breadcrumbs displayed and escaped.');
 
     // Check the breadcrumb on the term delete page.
     $this->drupalGet('taxonomy/term/' . $term->id() . '/delete');
-    $breadcrumbs = $this->getSession()->getPage()->findAll('css', 'nav.breadcrumb ol li a');
+    $breadcrumbs = $this->cssSelect('nav.breadcrumb ol li a');
     $this->assertIdentical(count($breadcrumbs), 2, 'The breadcrumbs are present on the page.');
-    $this->assertIdentical($breadcrumbs[0]->getText(), 'Home', 'First breadcrumb text is Home');
-    $this->assertIdentical($breadcrumbs[1]->getText(), $term->label(), 'Second breadcrumb text is term name on term delete page.');
-    $this->assertEscaped($breadcrumbs[1]->getText(), 'breadcrumbs displayed and escaped.');
+    $this->assertIdentical((string) $breadcrumbs[0], 'Home', 'First breadcrumb text is Home');
+    $this->assertIdentical((string) $breadcrumbs[1], $term->label(), 'Second breadcrumb text is term name on term delete page.');
+    $this->assertEscaped((string) $breadcrumbs[1], 'breadcrumbs displayed and escaped.');
   }
 
 }
diff --git a/core/modules/taxonomy/tests/src/Functional/TermTranslationTest.php b/core/modules/taxonomy/src/Tests/TermTranslationTest.php
similarity index 97%
rename from core/modules/taxonomy/tests/src/Functional/TermTranslationTest.php
rename to core/modules/taxonomy/src/Tests/TermTranslationTest.php
index bd9085017b64c6da7fef6e745c909a8ee9d5b9d2..ccb16f611db5b7471a9252b4d8ca1ab58c16cf3a 100644
--- a/core/modules/taxonomy/tests/src/Functional/TermTranslationTest.php
+++ b/core/modules/taxonomy/src/Tests/TermTranslationTest.php
@@ -1,9 +1,9 @@
 <?php
 
-namespace Drupal\Tests\taxonomy\Functional;
+namespace Drupal\taxonomy\Tests;
 
 use Drupal\Core\Url;
-use Drupal\Tests\system\Functional\Menu\AssertBreadcrumbTrait;
+use Drupal\system\Tests\Menu\AssertBreadcrumbTrait;
 
 /**
  * Tests for proper breadcrumb translation.