diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Core/Form/JavascriptStatesTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Core/Form/JavascriptStatesTest.php
index cc0c1df..7d686ae 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Core/Form/JavascriptStatesTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Core/Form/JavascriptStatesTest.php
@@ -2,7 +2,7 @@
 
 namespace Drupal\FunctionalJavascriptTests\Core\Form;
 
-use Behat\Mink\Element\DocumentElement;
+use Behat\Mink\Element\TraversableElement;
 use Drupal\FunctionalJavascriptTests\JavascriptTestBase;
 
 /**
@@ -26,22 +26,22 @@ public function testCheckboxTriggeredElements() {
 
     $trigger = $page->findField('checkbox_trigger');
 
-    // Initial state: before the checkbox trigger is checked.
+    /* Initial state: before the checkbox trigger is checked. */
 
     // Test that the textfield is visible.
-    $this->assertTrue($page->findField('textfield_invisible_when_checkbox_trigger_checked')->isVisible());
+    $this->assertFieldVisible('textfield_invisible_when_checkbox_trigger_checked');
     // Test that the details element is collapsed so the textfield inside is not
     // visible.
-    $this->assertFalse($page->findField('textfield_in_details')->isVisible());
+    $this->assertFieldNotVisible('textfield_in_details');
 
     // Change state: check the checkbox.
     $trigger->check();
 
     // Test that the textfield is not visible anymore.
-    $this->assertFalse($page->findField('textfield_invisible_when_checkbox_trigger_checked')->isVisible());
+    $this->assertFieldNotVisible('textfield_invisible_when_checkbox_trigger_checked');
     // Test that the details element is now open so the textfield inside is now
     // visible.
-    $this->assertTrue($page->findField('textfield_in_details')->isVisible());
+    $this->assertFieldVisible('textfield_in_details');
 
     // Change back to the initial state to avoid issues running the next tests.
     $trigger->uncheck();
@@ -55,19 +55,18 @@ public function testTextfieldTriggeredElements() {
     $page = $this->getSession()->getPage();
 
     $trigger = $page->findField('textfield_trigger');
+    $target = $page->findField('checkbox_unchecked_when_textfield_trigger_filled');
 
-    // Initial state: before the textfield is filled.
+    /* Initial state: before the textfield is filled. */
 
     // Test that the checkbox is checked.
-    $this->assertTrue($page->findField('checkbox_unchecked_when_textfield_trigger_filled')
-      ->isChecked());
+    $this->assertTrue($target->isChecked());
 
     // Change state: fill the textfield.
     $trigger->setValue('filled');
 
     // Test that the checkbox is not checked anymore.
-    $this->assertFalse($page->findField('checkbox_unchecked_when_textfield_trigger_filled')
-      ->isChecked());
+    $this->assertFalse($target->isChecked());
 
     // Change back to the initial state to avoid issues running the next tests.
     $trigger->setValue('');
@@ -84,18 +83,18 @@ public function testRadiosTriggeredElements() {
 
     $trigger = $page->findField('radios_trigger');
 
-    // Initial state: before the radios is checked.
+    /* Initial state: before the radios is checked. */
 
     // Test that the fieldset element is not visible so the textfield inside is
     // not visible either.
-    $this->assertFalse($page->findField('textfield_in_fieldset')->isVisible());
+    $this->assertFieldNotVisible('textfield_in_fieldset');
 
     // Change state: check the 'Value 2' radio.
     $trigger->selectOption('value2');
 
     // Test that the fieldset element is now visible so the textfield inside is
     // also visible.
-    $this->assertTrue($page->findField('textfield_in_fieldset')->isVisible());
+    $this->assertFieldVisible('textfield_in_fieldset');
 
     // Change back to the initial state to avoid issues running the next tests.
     $trigger->selectOption('value1');
@@ -112,44 +111,44 @@ public function testCheckboxesTriggeredElements() {
     $trigger2 = $page->findField('checkboxes_trigger[value2]');
     $trigger3 = $page->findField('checkboxes_trigger[value3]');
 
-    // Initial state: before any of the checkboxes is checked.
+    /* Initial state: before any of the checkboxes is checked. */
 
     // Test that textfield dependant on checkbox 'value2' is not visible.
-    $this->assertFalse($page->findField('textfield_visible_when_checkboxes_trigger_value2_checked')->isVisible());
+    $this->assertFieldNotVisible('textfield_visible_when_checkboxes_trigger_value2_checked');
     // Test that textfield dependant on checkbox 'value3' is not visible.
-    $this->assertFalse($page->findField('textfield_visible_when_checkboxes_trigger_value3_checked')->isVisible());
+    $this->assertFieldNotVisible('textfield_visible_when_checkboxes_trigger_value3_checked');
 
     // Change state: check the 'Value 1' checkbox.
     $trigger1->check();
 
     // Test that textfield dependant on checkbox 'value2' is still not visible.
-    $this->assertFalse($page->findField('textfield_visible_when_checkboxes_trigger_value2_checked')->isVisible());
+    $this->assertFieldNotVisible('textfield_visible_when_checkboxes_trigger_value2_checked');
     // Test that textfield dependant on checkbox 'value3' is still not visible.
-    $this->assertFalse($page->findField('textfield_visible_when_checkboxes_trigger_value3_checked')->isVisible());
+    $this->assertFieldNotVisible('textfield_visible_when_checkboxes_trigger_value3_checked');
 
     // Change state: check the 'Value 2' checkbox.
     $trigger2->check();
 
     // Test that textfield dependant on checkbox 'value2' is now visible.
-    $this->assertTrue($page->findField('textfield_visible_when_checkboxes_trigger_value2_checked')->isVisible());
+    $this->assertFieldVisible('textfield_visible_when_checkboxes_trigger_value2_checked');
     // Test that textfield dependant on checkbox 'value3' is still not visible.
-    $this->assertFalse($page->findField('textfield_visible_when_checkboxes_trigger_value3_checked')->isVisible());
+    $this->assertFieldNotVisible('textfield_visible_when_checkboxes_trigger_value3_checked');
 
     // Change state: check the 'Value 3' checkbox.
     $trigger3->check();
 
     // Test that textfield dependant on checkbox 'value2' is still visible.
-    $this->assertTrue($page->findField('textfield_visible_when_checkboxes_trigger_value2_checked')->isVisible());
+    $this->assertFieldVisible('textfield_visible_when_checkboxes_trigger_value2_checked');
     // Test that textfield dependant on checkbox 'value3' is now visible.
-    $this->assertTrue($page->findField('textfield_visible_when_checkboxes_trigger_value3_checked')->isVisible());
+    $this->assertFieldVisible('textfield_visible_when_checkboxes_trigger_value3_checked');
 
     // Change state: uncheck the 'Value 2' checkbox.
     $trigger2->uncheck();
 
     // Test that textfield dependant on checkbox 'value2' is now invisible.
-    $this->assertFalse($page->findField('textfield_visible_when_checkboxes_trigger_value2_checked')->isVisible());
+    $this->assertFieldNotVisible('textfield_visible_when_checkboxes_trigger_value2_checked');
     // Test that textfield dependant on checkbox 'value3' is still visible.
-    $this->assertTrue($page->findField('textfield_visible_when_checkboxes_trigger_value3_checked')->isVisible());
+    $this->assertFieldVisible('textfield_visible_when_checkboxes_trigger_value3_checked');
 
     // Change back to the initial state to avoid issues running the next tests.
     $trigger1->uncheck();
@@ -166,40 +165,40 @@ public function testSelectTriggeredElements() {
 
     $trigger = $page->findField('select_trigger');
 
-    // Initial state: before any option of the select box is selected.
+    /* Initial state: before any option of the select box is selected. */
 
     // Test that item element dependant on select 'Value 2' option is not
     // visible.
-    $this->assertFalse($page->find('css', '#edit-item-visible-when-select-trigger-has-given-value')->isVisible());
+    $this->assertSession()->assertElementNotVisible('css', '#edit-item-visible-when-select-trigger-has-given-value');
     // Test that textfield dependant on select 'Value 3' option is not visible.
-    $this->assertFalse($page->findField('textfield_visible_when_select_trigger_has_given_value')->isVisible());
+    $this->assertFieldNotVisible('textfield_visible_when_select_trigger_has_given_value');
     // Test that textfield dependant on select 'Value 2' or 'Value 3' options is
     // not visible.
-    $this->assertFalse($page->findField('textfield_visible_when_select_trigger_has_given_value_or_another')->isVisible());
+    $this->assertFieldNotVisible('textfield_visible_when_select_trigger_has_given_value_or_another');
 
     // Change state: select the 'Value 2' option.
     $trigger->setValue('value2');
 
     // Test that item element dependant on select 'Value 2' option is now
     // visible.
-    $this->assertTrue($page->find('css', '#edit-item-visible-when-select-trigger-has-given-value')->isVisible());
+    $this->assertSession()->assertElementVisible('css', '#edit-item-visible-when-select-trigger-has-given-value');
     // Test that textfield dependant on select 'Value 3' option is not visible.
-    $this->assertFalse($page->findField('textfield_visible_when_select_trigger_has_given_value')->isVisible());
+    $this->assertFieldNotVisible('textfield_visible_when_select_trigger_has_given_value');
     // Test that textfield dependant on select 'Value 2' or 'Value 3' options is
     // now visible.
-    $this->assertTrue($page->findField('textfield_visible_when_select_trigger_has_given_value_or_another')->isVisible());
+    $this->assertFieldVisible('textfield_visible_when_select_trigger_has_given_value_or_another');
 
     // Change state: select the 'Value 3' option.
     $trigger->setValue('value3');
 
     // Test that item element dependant on select 'Value 2' option is not
     // visible anymore.
-    $this->assertFalse($page->find('css', '#edit-item-visible-when-select-trigger-has-given-value')->isVisible());
+    $this->assertSession()->assertElementNotVisible('css', '#edit-item-visible-when-select-trigger-has-given-value');
     // Test that textfield dependant on select 'Value 3' option is now visible.
-    $this->assertTrue($page->findField('textfield_visible_when_select_trigger_has_given_value')->isVisible());
+    $this->assertFieldVisible('textfield_visible_when_select_trigger_has_given_value');
     // Test that textfield dependant on select 'Value 2' or 'Value 3' options is
     // still visible.
-    $this->assertTrue($page->findField('textfield_visible_when_select_trigger_has_given_value_or_another')->isVisible());
+    $this->assertFieldVisible('textfield_visible_when_select_trigger_has_given_value_or_another');
 
     // Change back to the initial state to avoid issues running the next tests.
     $trigger->setValue('_none');
@@ -215,25 +214,25 @@ public function testMultipleTriggeredElements() {
     $selectTrigger = $page->findField('select_trigger');
     $textfieldTrigger = $page->findField('textfield_trigger');
 
-    // Initial state: before any option of the select box is selected.
+    /* Initial state: before any option of the select box is selected. */
 
     // Test that item element dependant on select 'Value 2' option and textfield
     // is not visible.
-    $this->assertFalse($page->find('css', '#edit-item-visible-when-select-trigger-has-given-value-and-textfield-trigger-filled')->isVisible());
+    $this->assertSession()->assertElementNotVisible('css', '#edit-item-visible-when-select-trigger-has-given-value-and-textfield-trigger-filled');
 
     // Change state: select the 'Value 2' option.
     $selectTrigger->setValue('value2');
 
     // Test that item element dependant on select 'Value 2' option and textfield
     // is still not visible.
-    $this->assertFalse($page->find('css', '#edit-item-visible-when-select-trigger-has-given-value-and-textfield-trigger-filled')->isVisible());
+    $this->assertSession()->assertElementNotVisible('css', '#edit-item-visible-when-select-trigger-has-given-value-and-textfield-trigger-filled');
 
     // Change state: fill the textfield.
     $textfieldTrigger->setValue('filled');
 
     // Test that item element dependant on select 'Value 2' option and textfield
     // is now visible.
-    $this->assertTrue($page->find('css', '#edit-item-visible-when-select-trigger-has-given-value-and-textfield-trigger-filled')->isVisible());
+    $this->assertSession()->assertElementVisible('css', '#edit-item-visible-when-select-trigger-has-given-value-and-textfield-trigger-filled');
 
     // Change back to the initial state to avoid issues running the next tests.
     $selectTrigger->setValue('_none');
@@ -242,4 +241,31 @@ public function testMultipleTriggeredElements() {
     $textfieldTrigger->keyUp(8);
   }
 
+  /**
+   * Asserts that the given field is visible.
+   *
+   * @param string $locator
+   *   One of id|name|label|value for the field.
+   * @param \Behat\Mink\Element\TraversableElement $container
+   *   (optional) The document to check against. Defaults to the current page.
+   */
+  public function assertFieldVisible($locator, TraversableElement $container = NULL) {
+    $this->assertSession()->assertElementVisible('named', ['field', $locator], $container);
+  }
+
+  /**
+   * Asserts that the given field is not visible.
+   *
+   * @param string $locator
+   *   One of id|name|label|value for the field.
+   * @param \Behat\Mink\Element\TraversableElement $container
+   *   (optional) The document to check against. Defaults to the current page.
+   *
+   * @throws \Behat\Mink\Exception\ElementNotFoundException
+   *   When the element doesn't exist.
+   */
+  public function assertFieldNotVisible($locator, TraversableElement $container = NULL) {
+    $this->assertSession()->assertElementNotVisible('named', ['field', $locator], $container);
+  }
+
 }
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/JSWebAssert.php b/core/tests/Drupal/FunctionalJavascriptTests/JSWebAssert.php
index 8d3ff47..5e8bbe9 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/JSWebAssert.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/JSWebAssert.php
@@ -2,6 +2,10 @@
 
 namespace Drupal\FunctionalJavascriptTests;
 
+use Behat\Mink\Element\Element;
+use Behat\Mink\Element\ElementInterface;
+use Behat\Mink\Exception\ElementHtmlException;
+use Behat\Mink\Exception\ElementNotFoundException;
 use Drupal\Tests\WebAssert;
 
 /**
@@ -28,4 +32,92 @@ public function assertWaitOnAjaxRequest($timeout = 10000, $message = 'Unable to
     }
   }
 
+  /**
+   * Asserts that the specific element is visible on the current page.
+   *
+   * @param string $selector_type
+   *   The element selector type (css, xpath).
+   * @param string|array $selector
+   *   The element selector.
+   * @param \Behat\Mink\Element\ElementInterface $container
+   *   The document to check against.
+   *
+   * @throws \Behat\Mink\Exception\ElementNotFoundException
+   *   When the element doesn't exist.
+   */
+  public function assertElementVisible($selector_type, $selector, ElementInterface $container = NULL) {
+    $container = $container ?: $this->session->getPage();
+    $node = $container->find($selector_type, $selector);
+    if ($node === NULL) {
+      if (is_array($selector)) {
+        $selector = implode(' ', $selector);
+      }
+      throw new ElementNotFoundException($this->session->getDriver(), 'element', $selector_type, $selector);
+    }
+    $message = sprintf(
+      'Element "%s" is not visible.',
+      $this->getMatchingElementRepresentation($selector_type, $selector)
+    );
+    $this->assertElement($node->isVisible(), $message, $node);
+  }
+
+  /**
+   * Asserts that the specific element is not visible on the current page.
+   *
+   * @param string $selector_type
+   *   The element selector type (css, xpath).
+   * @param string|array $selector
+   *   The element selector.
+   * @param \Behat\Mink\Element\ElementInterface $container
+   *   The document to check against.
+   *
+   * @throws \Behat\Mink\Exception\ElementNotFoundException
+   *   When the element doesn't exist.
+   */
+  public function assertElementNotVisible($selector_type, $selector, ElementInterface $container = NULL) {
+    $container = $container ?: $this->session->getPage();
+    $node = $container->find($selector_type, $selector);
+    if ($node === NULL) {
+      if (is_array($selector)) {
+        $selector = implode(' ', $selector);
+      }
+      throw new ElementNotFoundException($this->session->getDriver(), 'element', $selector_type, $selector);
+    }
+    $message = sprintf(
+      'Element "%s" is not visible.',
+      $this->getMatchingElementRepresentation($selector_type, $selector)
+    );
+    $this->assertElement(!$node->isVisible(), $message, $node);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function assertElement($condition, $message, Element $element) {
+    if ($condition) {
+      return;
+    }
+
+    throw new ElementHtmlException($message, $this->session->getDriver(), $element);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getMatchingElementRepresentation($selector_type, $selector, $plural = FALSE) {
+    $pluralization = $plural ? 's' : '';
+
+    if (in_array($selector_type, ['named', 'named_exact', 'named_partial'])
+      && is_array($selector) && 2 === count($selector)
+    ) {
+      return sprintf('%s%s matching locator "%s"', $selector[0], $pluralization, $selector[1]);
+    }
+
+    if (is_array($selector)) {
+      $selector = implode(' ', $selector);
+    }
+
+    return sprintf('element%s matching %s "%s"', $pluralization, $selector_type, $selector);
+  }
+
 }